Tune in next week for the dramatic conclusion. Already up to 3mm DOC in steel and I can definitely push it further. EDIT: Alright the internet convicted me to change the wiring, no need to comment further. Also the wring is already delta, you can probably see the connection terminal in the top right corner at the 16:36 mark. See you this Saturday
We should all pitch in and get this gentleman a band saw, I've seen him use a hacksaw in his videos more than I've used one my entire life. Great content 👍
@@woozhi9218 imo, stiffness. Stiffness is the biggest issue with these tiny lathes. When you get a motor with real power it twists these lathes like a noodle.
At 3:31 I totally expected you to say "I also can't stress enough how much it feels like a blue monster staring back at me". Those cable glands look like eyes!
Nice! I run a 2HP 3 phase on my mini lathe as that's what I had spare. You need to operate the VFD via remote, you can probably use the controls already on your lathe for the variable speed and forward/reverse, it saves having the VFD near the lathe and getting it oily with your fingers. Steve Jordan did a great video on doing it.
You only need an on/off switch, a direction switch, (You can combine both and use only two wires, and a potentiometer to control many VFDs. Add some safeties like the emergency stop and you are done. Keep the control box small voltage and current, and any actual power switch in a dedicate box with the VFD. Add RJ45 connectors at both ends, and you can place the control box whenewer you want. If you need more wires, use DB15 or DB25 connectors. Remember to keep the start/stop intelocked swhitch in the main power. You dont want the power going out and the lathe to start itself when it returns.
Great work. Got to say it's equal parts fun and scary to watch 😁 One of the more practical reasons to use an over-size motor, is that you can still get ample power out of the motor, even when it's running below rated frequency. This makes the single belt/pulley position a lot more usable than it otherwise would be. Good stuff.
Love it! I own a chinese mini lathe and one of my biggest complaints is the very low torque at slow speeds. I replaced the fuse with a circuit breaker and will overload and trip it when I'm trying to torque up on something at a low RPM. One must keep a meathook on the speed control to pull this off. It's one of several reasons that I'm on the hunt for a used 'big boy' lathe. Not only can I handler larger parts which has been another problem, I can get higher torque at lower rpm. Of course a motor swap out like this is another solution but I'm going right to a more complete solution to the shortcomings of the mini lathe. Don't misunderstand me. I've made a lot of great small precision parts with mine but if I had it to do all over again I would have bypassed the purchase and saved my money for a better lathe. I've also spent a fair bit of time making improvements to the mini lath. Hindsight of course always being 20-20.
Wow, what an upgrade! That is like a V8 weed wacker! I have a 15" swing gear head lathe that weighs 2300 LBS (1043 Kilos) and it uses a two speed, three phase, 3 HP motor. With that much power, depth of cut no longer becomes an issue for the hobbyist. Your new problem will be rigidity and damage if / when you make a mistake. I love the creative solutions to your problems, thank you for sharing.
Damn,I really ran the same thing with a 0,3 hp motor from ASEA motors(came with an old twin spindle attachment that was sexy enough at the time for me but while the whole contraption came as a "vintage" ARO drill mod 76** C,just for $460 while the brand new attachment from Rand Ingersoll costs about 4500$ alone so I took the deal of course!)-so it is obviously enough for an amateur machinist..Meanwhile I never understood why ever since 1980-s those "pneumatic auto feeders" are almost as expensive as they were yet barely anyone still uses them and their attachments are still produced by different companies and yet I see some of them on eBay for quarter of the price of the new..So anyway I just bought a real monster of a drill as an investment/for the ridiculously powerful 25hp motor that it has..And the only time I used it even to a fraction of it's power(BTW it has a 4" stroke,it's vertical and has a twin spindle attachment with 2×13mm chucks size)-it drove two carbide bits through a 5cm thick titanium piece without even slowing down,or any effort-and the whole thing is just over 120 lbs with motor and manual control unit,pneumatic self feeding system,cooling system and the rest..Just 10 seconds,one stroke,3900 rpm,air cooling selected-just a nice fire show of turnings and the drill just retracts up in less than a second..Isn't that insane?Nearly overloaded the grid of an entire house and according to the manual it can draw up to 1040 amps at 24vdc so quite serious even for a machine shop..Probably would easily power an entire array of similar drills along with a number of other automation systems,pistons and other stuff..
I can't believe I bought the same motor , well a 1.5kw 2hp version. I was thinking about the 3hp one but chickened out. I fitted it a week ago and I'm loving it, great motor and what a price.
Love the logic 'three is bigger than two' Glad you explained why your using carbide tooling, makes perfect sense when you have enough power and can't get low rpm. I have wondered what would happen with a two hp motor as I just happen to have one, going to three is total overkill but great fun. For brazed carbide, use a Dremel and a cheap Chinese diamond bit to re-shape top cutting edge for aluminium
I must admit I missed seeing the hacksaw in action when cutting down your 20mm flatbar to length.. I doubled the HP to 1hp on my small scope multi function machine and it made a big difference, 3hp is going to be interesting!
Two things I learned from welding classes: #1- When welding two pieces of steel like you did, grind a groove into both sides before welding to make a more solid weld. #2- Flux spray EVERYTHING to be welded for the most reliable and strongest weld possible!😊
my god. that thing is a real beast now. I have one of these 7x12 mini lathes, but I have never considered going to this level of extreme. I don't think the 42" toolbox that I have my lathe bolted to would be able to handle that level of upgrade.
LOL I thought putting 2HP on my Seig C6 was going to be overkill, however Im thinking of getting a 3HP one now to replace it and using the 2HP for my belt sander im building, thanks for all your videos I never miss one, as your are running pretty much the same kit I am.
Thank you very much for sharing your creation. In my mini lathe I made smaller motor pulley combined with bigger input at middle pulley and smaller output in the middle pulley also, if I needed i could have made a bigger and shaft pulley but didn't needed, it just became powerful enough too burn cutting tools and the lathe won't stall. The lathe has two set ups 1) 2500rpm that was useless for me. 2) 1250rpm which was good but i wanted more torque. Now after pulleys mod it runs 830rpm max and it's good enough speed with very good torque and it stalls only with parting tool sometimes. The pulley grooves was a perfect match with metric thread cutting tool for my mini lathe.
Just a thought - The three screws may have been intentional to avoid warping, since 3 points define a plane and the 4th may be over-constraining. Not sure if that applies here given all of the mating surface, though.
Possibly. However similar type lathes have 4. Mine does. Seig type. Vevor model. Sometimes they are lazy at the factory. You'll have bosses that aren't drilled and tapped yet should be. Missing screws, metal shavings in the headstock, Sand in the headstock....etc..... Good ol Chi-nuh.
I've got an old hafco al51 and the first thing I did was exactly this, a 3hp 3phase with a vfd, and I used two peices of 6mm flatbar under the lathe which made it easy to get the bed leveled. A lot more rigid than my old mini lathe and capable of far greater doc than would ever be done in practice. Had it taking 6mm doc in 6061! The ability to run more speed is nice which is great for the carbide I use, unfortunately not so great for vibrations due to my mounting
I have the same lathe as well. I just put a 2hp 3 phase and it's not bad but these videos make me wish i went for more. I am currently machining a replacement for the compound because it's flexing and wobbling all over the show. I wonder if you have the same crappy design and how you fixed it? It's just a thin plate held on with two small bolts that go into the T-slots. It's handy to have the compound but I am trying to eliminate as much flex as I can Apart from that, so far I really like the Lathe.
Be careful with the motor cooling while using VFD's . If you plan it to run a lot of time under ¿40 % - 30%? frequency the motor will burn after long sessions of use. The reason being the stock fan (mounted on the motor axis) is designed to keep it cool it at 100% frequency . Half the speed you around half the cooling (but not the heat ! it's more inefficient running it with an VFD!). For short sessions it should be okay. Or look for Forced Ventilation fan kits . Those have the fan with their own independent motor .
Its a 900 rpm motor, so its generally being run close to its normal speed. And for what it's worth, its not drawing a huge current, definitely no where close to 2kw. I had it running in today and for an hour or so in some 4140 and whist there is some heat being produced, its not close to being something i'd be concerned about.
That motor is Cookie Monster. I'm sitting here thinking how much it looks like Cookie Monster, and then here comes an Oscar the grouch mug on the screen suddenly, and it's like I'm on the set of Sesame Street.
Love this build. As others have noticed, the spindle locking nut sits quite far back due to the wider spindle pulley. To get more threads engaged by the spindle locking nut, you could machine yet another spindle pulley larger in diameter to accommodate a large diameter counter bore for the locking nut. The counter bore would be just deep enough to allow the nut to engage all the threads. Of course this restricts access for a spanner wrench, so that problem would need to be solved. An offset wrench, or a pin style wrench might solve that issue. Of course the larger pulley gives a slower speed for the same motor rpm, but that might not be an issue. You could always change the motor pulley if that even made sense.
It’s sat like that for the past 3 years. It’s always been one of those things I’d get around to doing. Like a custom nut but never had to time to. But hey it’s never been a huge problem. Yet anyway
nice work. I quit fighting my mini lathe and just went with a 10x22. the biggest headache ive had is putting it on a wooden workbench. everything else has been gravy.
To get slower speeds from a drill press you need to use the spindle of the drill press as a countershaft. I'm doing that, i got a central machinery 5 speed drill press and it has a 2/5 HP motor, better than 1/3 and not as good as 1/2. If you use the spindle as a countershaft then you can gear it down more and get more torque and slower speeds. The slow speed on the drill press is 760 but using the spindle as CS I get half that on the lathe. I had to take the spindle out and turn down the part where the chuck goes to 12 mm then I got a 17 tooth timing pulley with a 12mm bore, that is the same number of teeth as the lathe motor came with. The nice thing about that is that you can use the whole drill press head casting so it's all lined up. Then you just need to come up with a slide for the whole assembly for belt tension.
Next step - put stepper motors on the lead screws and turn it into a CNC lathe. There are some low cost GRBL control boards that you can run it with. If you don't wanna wire up the VFD you can have a servo motor controlling the knob directly xD
I have just installed a 2hp 3 phase motor with a VFD on my Clarke CL430 lathe replacing the 3/4 hp single phase motor . I only used 2Hp because a used one came up on eBay with a quality KBAC inverter. It was a bit of a challange to get the motor to fit the existing adjuster plate and get it all lined up. It is now so much better to use with 170 to 1700rpm without swapping belts.
Fair bit to discuss here. Firstly, I have a minilathe as well - maybe slightly bigger than yours (what would be considered a 7" lathe, but has more mass) - I run a 1.5kW 3ph motor - but I wire it in 415v mode ("Star " aka "Wye" configuration) on a single phase 240v VFD - I can tell it's the same as how I saw how you have wired yours, where the resulting power maybe ends up around half that, and this is more than enough to perform huge depth of cuts, but you're still in the "grey area" of snapping cast iron in half if you crash it. DO NOT WIRE IT IN DELTA CONFIGURATION - that would remove all doubt to causing permanent damage. Next, with VFDs, the lower the frequency, the higher the current draw - now you've wired it in star config - which is a good start as the coil resistance is increased, but you should be cautious of running the motor under 20Hz - there is a small risk of blowing up the VFD (recently happened in a FB group I'm a member of), but that risk is lowered due to the star config and 240v input. If you read the VFD manual - it should have a "Max current" setting - good to set to the max rated current on the motor's spec plate + 10%, and "Minimum RPM" (Set to 15-20Hz). Max RPM is typically 80Hz before 3ph motors begin being inefficient, but if you're finding yourself at 80Hz and wanting more - you should probably redesign primary the pulley ratio, or add pulley ratio options so it requires a belt change, 95% of your work should be within the 25-75Hz range without any belt change. Some other VFDs can also display "Alternative RPM" (by using a multiplier against the frequency) - so depending on your pulley setup, you can have it read out true spindle RPM instead of just the 3ph frequency. I never got around to doing this on mine and have come to know it intuitively, but might be beneficial to you if you get this set up before you end up getting used to it, like I have. With bigger depth of cuts, more RPM, more power - come more heat. It's time to invest in a "mist cooling system". They're $30 on eBay and need a 30psi air feed and (ideally) a source of semi-synthetic coolant mix (or plain water at minimum). It's either that, or you'll continue to burn out your carbide. I'm very much like you in that respect - just preferring to use carbide, never had HSS - but you'll find that has it's limits as well, so do yourself a favour and get a coolant setup going. Next, consider a diamond wheel setup where you can touch up your tools - a couple of 6" diamond wheels is $150 on eBay (600 grit, 120 grit), and makes for another decent project + learning curve to build the sharpening station and technique to use it, to optimise your lathe work. A properly freshened-up, mirror-finished brazed lathe tool is really something to behold. Love your work - as I continue my own journey somewhat in parallel to yours.
Cheers mate. For what its worth, the manual for the VFD states to use triangle/delta for the wiring and not to use wye. Doesn't look like I'll be going below 20hz for this motor, unless in reaming or threading. Already looking into a spray coolant, the work is really heating up with these cuts.
-All 3 phase motors are wired Delta even when you supply them with y like 120/208y. Delta is a phase to phase reference and y is a phase to ground reference. -amps will go up with load not frequency or cycles.
@@LitchKB Because this HELPFUL drivel is actually correct.The voltage specified is 240/415, which means a single winding should not exceed 215V. Using delta on a star motor will result in too high currents and thus irrevocable damage. There is only ONE exception and nobody ever tried to explain it properly. Which is the case of single phase to three phase converters. The voltage between phases will become 230V instead of the normal 400V you would normally get from real three phase power.
@@patrickd9551 out of context morons arguing points that were never made is unhelpful drivel. The spec plate will show the voltages and wiring configurations. Simple. That, in addition to using VFD current and power limits is how it's done. No on is telling anyone to wire the motor in delta with star voltages, so again you're just another nuffy arging with a point that was never made.
Wow Bold move with the 3Hp. It's nice to have variable speed capability but safety must come first as this motor will put so much torque that the spindle and chuck may suffer. We would all like a lathe to cut deeper and faster but there are limits to all tooling and a 2mm cut for this type of lathe is very good. As machinist quality of manufacture should be our objective at the lost cost possible. Looking forward to your up coming builds,
I actually have a 1.4KW three phase motor attached to the minilathe, new from the factory when I put my hands on it. Salvaged from an industrial diswasher broken water pump. If you know where to look, it's not dificult getting this kind of motors for free, even new ones. I must recognize I have it very easy, I'm the head (and only member) of the returns and guarantees department of an spare parts seller for hostelry appliances. I just need to pick what seems interesting from what I send to the trash for reasons like damage during delivery and not economic to repair. I have more monophase motors at home that I can use in my whole live, a wide range of powers. :-) (And some nice three phases ones). But seriously, learn where to look for these motors and other parts. A lot of industries dispose of perfectly working motors because the part they are part of have some flaw that doesn't affect the motor and is not economic to repair.
I love the idea, and I always see your videoes, keep up the good work! When it comes to motors, you should look more at torque than HP, but it is very common also amongst car and motorcycle enthutiast, that the relation between torque and hp is misunderstodd or forgotten. Torque can be stationary, torque does not say anything about movement. HP is both torque and movement in the same designation. That means that hp is both torque and rpm in the same designation, where torque is only a force. To compare motors, you need to know both the hp, torque and the rpm, because on the lathe you will gear it to suit the rpm with pulleys. You have chosen a 900 rpm 3 hp motor, that motor have 22,5 Nm of torque and comes in a 112 frame - no wonder you think it is big, it has the same torque and frame size as a 9 hp motor that runs 2800 rpm. That is a lot of motor for that lathe 🙂 All that said, I have 4kw 27 NM 1400 rpm motor waiting for my 13" lathe, just like you, I don´t want to fiddle with belt and pulley change. I don´t know if I can post links, but here is an easy chart, where you can compare motors. www.seipee.it/wp-content/uploads/2019/03/Motori-Standard_JM_GDM.pdf
That's pretty neat. It will be interesting to see if you can resist the urge to push the lathe til something fails. Hopefully not. I almost bought a used chY-knees mini-lathe that had a motor upgrade done to it. The seller was selling it without the motor for only $100 usd. Everything else seemed to all be there. I inspected it carefully and noticed that the bed had a slight twist in it. I assume it had a sudden stop/bind that did it in. Just be aware. Good luck.
When I seen that bit of plate I thought holy crap! And then you said that you were going to cut it down to size. 🤣 Then I thought, how on earth is he going to cut THAT? That's a gutsy effort cutting a bit of 20mm plate with an Ozito 4" angle grinder. Then you backed it up and did it again. GO YOU LITTLE AUSSIE CHAMPION! Have you thought about putting a recess in the spindle pulley so the nut gets a little more purchase on the threads? I know you are probably going to anyway. You really should have double insulated wiring for the motor. Because safety. And some proper start stop switches with a magneticly latched E-stop. That thing has decent power now. Will be good to see what can be done with that machine. Nice one.
Man that there is awesome. Over here in the u.s we use commercial sewing machine motors. Most of them come with a variable speed controller and produce a insane amount of torque and be 3× smaller than the 3hp motor you used. The range on most of the sewing machine motor is 100 rpm up to 4000 rpm. Even though small chucks aren't rated for more than 2500 rpm max 😂. Glad to see the upgrade though man. You may or may not be familiar with the guy, but his name is ade. His channel is Ades workshop. That guy is super smart with mini lathes as well. Might be worth your time looking into his channel and gain more knowledge or ideas for your shop.
I would not have thought a sewing machine motor was suitable. They are series-connected universal motors, which means their RPM is inversely proportional to torque. This means the chuck rpm will vary a lot depending on depth of cut, turning radius, etc. Also, they are not designed to work full load for any length of time - that's why they can be so small. A lathe will make the motor work CONSIDERABLY harder than a sewing machine will.
@@keithammleter3824 have you looked at the power of a commercial sewing machine motor? The materials those thing have to push a needle through, there's no stopping that thing nor slowing it down. For a mini lathe, there almost perfect match.
@@artisanmakes yes that's what they call them servo motors. That's cool part about mini lathes you can use just about any motor to run them as long as it makes decent torque.
Also called consew motors, I have a 1hp one on my lathe with a small 4 rib belt, has a serous crash a few months ago, and it smoked the belt instead of stalling the motor.
16:30, i'd take a look at the wobble on the pulleys. That could end up bad if you're pushing the lathe and the motor puts too much torque on the spindle. Also those welds for the baseplate for the motor looks like an extra safety feature for over torque :D Also also, watch the temperature of the motor when using it at low speeds and pushing the motor. The VFD only changes the frequency, not the amps, so the motor will still use a lot of amps and with the low speed, the fan would have less effect because it's directly connected the the rotor. But great video and hope to see more niece upgrades for the mini lathe and mill.
The threads themselves are a little eccentric. There’s not much that I’ve ever been able to do about that. The heat ain’t much of an issue. We aren’t really using that much current to take the cuts, at least nowhere near the motors rating
The current drawn depends mainly on the mechanical load applied. The no-load current is very low, only overcoming friction in bearings and belt, plus any fan loading and windage. Available torque drops significantly at low speed, mainly because the frequency slippage (ratio of applied to actual) is limited- this reduces the current taken.
@@Tensquaremetreworkshop Along the lines of this, I measured the current draw from the wall and it is rarely going over 1000w. All in all the heat is not so bad and very manageable
@@peterfitzpatrick7032 It is not the load of the motor that is the problem. Problem is that motor still gets 2,2kW of energy, but slower RPM is also on the fan that is cooling the motor and this way motor does not get enough cooling. Believe me, this is problem for this kind of setup.
@@Slemi The motor will not "draw" 2.2 kW unless the torque is at the maximum allowable level. The VFD varies the current depending on the load. You're still correct that the fan will be less efficient at low speed, but it's not as bad as full current and full voltage all the time.
Eh, nothing an RPM-triggered blower fan a few inches away from the motor fan intake can’t handle... I mean something like ‘if rpm below xx, fan ON, else OFF’
I've been thinking about taking one of these and doing an upgrade series. Starting with the small mods, eventually casting it in epoxy granite and bolting it to the bed of my 10hp Daewoo. And of course, running a driveshaft to the spindle of it to have a 10hp minilathe. Maybe someday haha.
Why is the pulley on the lathe shaft wobbling? That could damage bearings or give you uneven finish on the parts. Also, I noticed to provision for belt adjustment.
You seem to be doing exactly same steps I did with my lathe. It's bigger and came with 1.1kw motor. Next phase would be to make variable transmission which uses scooter belt. It's quite simple since ratio is manually adjustable. It provides much better stability and torque on low rpm's. It have clear influence on surface quality. By the way, in your setup, you must add separate cooler for your motor. Otherwise you burn it with low rpm.
limiting factor on this mini lathes are the headstock bearing, spindle and casting size/thickness/intended duty and the bed/crosslide widths. Interesting experiment nontheless.
With increasing your lathe’s power you may also want to consider taking a look at your tool post. In many tool post systems the sizing is determined by lathe power, presumably so it doesn’t break. The multifix style tool post I was recommended by the spec sheet for my 3kW lathe is surprisingly big. Maybe consider a faceshield in the meantime ;)
@@artisanmakes Keep eye out for developing cracks in the casting now that you have lots more power and more over temperatures of different parts. On glance those wires going from VFD to motor seemed bit thin. My unit is way smaller and need 2.5m2 wires, those looked like 1.5m2. Also since its lathe and there will be wire spaghetti, you might want to add wire cover and strain relief for the cable, well as prevent any of those going into wire port and touching up into the poles. Unlikely event but its tool and anything can happen and you dont want sparks flying or shorting the VFD if spaghetti catches on the wire for instance. Dont get me even started with the metal dust. Belt cover and boxing the VFD with remote control box would be good addition as well. We all know those are not cheap so might as well go extra mile protecting it.
Have you changed the motor connection from star to delta ? You won't get full power with vfd without it. You need to turn 3 bars in the motor terminal block
You can bolt a plate to the headstock. And connect it with a thick metal piece down to the table. It would be more sturdy and have less flex when turning harder steels.
I think the headstock was way too small to be bolting that much to it. In any event I don't think there was much left to come out of it, regardless of where the motor was bolted
Very cool upgrade. I have the same issue with my lathe. I plan on using a sewing maching adjustable speed motor - and yes, motors prices have gone through the roof!
Didn't read all the comments, so I'm not sure if someone already said this, but when running a VFD from single phase, you need to de-rate the VFD by 50%, so you need at least a 6hp VFD to run a 3 hp motor at full load on single phase
You say you've fitted a 3hp motor to your mini lathe, but I think it could easily be argued that what you've ACTUALLY done is fitted a mini lathe to your 3hp motor ! :D
Yes, a bigger motor is definitely an improvement but I see this more as a way to get a more stable speed than doing heavy cuts. With a big motor, you risk damaging your spindle bearings, shearing off the compound slide (that you luckily already removed) or even twisting the bed. My Wabeco D4000 mini lathe has a 1.4 kW motor which is what it comes with from the factory and I think this is still on the small side since the spindle speed varies quite a bit - especially on the start of a cut.
It’s in the works but I just haven’t had the time to get around to do that. Plus the old big v belt got burnt up last year so I’ll have to order a new one
I was always told to go about 10% over on VFD's and more on chinese ones but i take it you have a good supply to your house/garage so its probably not a big deal (Also worth checking how balanced the lines are into the motor underload cause they can burn out quicker similar to running them off rotary phase converters)... Only real word of advise i can give for having that much power is having a safety guard and the use of steady rests etc because if a piece slips out it will do real damage ( I have a hercus 9" i had this upgrade on but went back to smaller motor when i brought a big 7hp turret lathe..both will kill without a 2nd thought) Awesome work and keep it up :)
You should make yourself a small power hacksaw. I used to have one that took 10” blades, could do whatever size blades you use. It would only need a small motor and save you a lot of effort on cutting your stock. Done right and it would always cut super straight as well. Wouldn’t always replace the hand hacksaw but would be good for cutting bar stock
That’s the same size motor as my 13”x28” southbend! And the same exact vfd. Benefit of the bigger lathe and gearing is rigidity and depth of cut. Biggest cut I’ve taken is .300” /7.6mm. Only because I ran out of cutting edge on my tool
As long as the spindle and bearings can handle it, no motor is too big 😂 You probably need a belt tensioner and a V belt that's fully wrapped, otherwise you're going to get black belt residue everywhere.
HotRod- lathe: Thanks to the VFD that big motor can always be dialed down, you can get off the throttle in a V8 but you cant get V8- power from a threebanger :)
You can't reduce the speed with the VFD by as much as you might think, because the lower frequency increases current drawn and also significantly reduces cooling in the motor.
Just saw your video.. I installed a 3hp (2.2kw) motor on my 10"x 20" lathe and I was wondering if I should use a smaller unit to save some space... then I see you have installed on a mini lathe. Anyway you can limit the power in the VFD and the bigger motor will have better low end torque so you will get the full power up to the limit in the VFD right down at low RPM.
I am putting a 2.5 HP motor on my mini mill . It has a 3/4 HP on it now but I have a need for more power .. I bought the 4 inch vice you have on you mill .. going to put it all together soon .. I think 3 HP is fine as long as you don't push it to hard .. I enjoyed , thanks ! Hey , I would enjoy more go kart vids to ..
I have watched this more than once, very exciting. I did a 1hp 3 phase with VFD about 8 months ago. Best decision ever. You'll not be disappointed. Does the VFD have an output to connect a potentiometer? It's a great way to control the rpm, also a hall effect tacho is great to read spindle speed instead of calculating any gear reduction or multiplier you have in pulleys.
It is in the wiring diagram that it can be connected to a potentiometer, and there are connections for one. I just havent gotten around to doing it yet.
You need to change the motor wiring to delta. Check inside of the cover plate / manual. Star is for 415v 3ph. Your vfd only outputs 240v 3ph, which means you need the motor in the delta configuration. I'm currently doing the same upgrade, 2hp version of that motor.
which belt do you use for the new motor? I still need to upgrade the belt of my lathe because it's slipping too much. I have a 1.5hp motor attached but it's worthless due to the bad belt.
You are going to have a lot of broke tools and possibly a broken lathe as well. Just think of the tourque with the machine in low gear. My 5.5 in center height Colchester Chipmaster had a 3hp motor. That machine was a heavy duty production machine tool that weighed half a ton.
Careful with the vfd - they are great, but most induction motors are meant to spin at a specific rpm so you lose a lot of cooling at low rpms. The other thing to keep in mind is that when you use gearing to reduce rpm you multiply torque, but when you use a vfd you lose torque the lower the rpm you run it at. Some people have trouble with stalling at low rpms. You probably already know all of this (if I remember right your old lathe used a very noisy vfd)....
Its a 900 rpm motor, so its generally being run close to its normal speed. And for what it's worth, its not drawing a huge current, definitely no where close to 2kw. I had it running in today and for an hour or so in some 4140 and whist there is some heat being produced, its not close to being something i'd be concerned about.
I was disappointed with my VFD. I have an old but much bigger 3 phase lathe and bought a 4kW VFD as, like you, I don't have 415V. Turns out the VFD is not big enough as it only puts out the rated power if you input 3 phase - otherwise divide by power at least 2. It also puts out 240V per phase not 415V, so I had to rewire the motor to delta configuration. The VFD overheats and trips out if I push it. In the end I went the other way, removed the 3 phase motor and replaced it with a single phase motor, it's much better, even if it has 1/2 the rated power of the original 3ph motor. In your case I think you will be OK, as you started with a low powered motor and the higher reduction via the pulleys will make a big difference with the higher torque. I hope the power at the high speeds are not adversely effected, and if it is possible on your motor, it might be best to rewire it to Delta. I enjoy your videos - keep it up and good luck with the project.
My physics is really rusty, but... A 3 phase supply is 415V phase to phase and 240V neutral to phase. In his street there will be 3 phase power. His house will just be connected directly to neutral and one of the phases (and his neighbours to the other phases in an attempt to keep them balanced).
@@georgescott6967 What you say is true but my VFD is 220V between phases not 415V. At the time I bought mine, VFD's were available with true 415V but cost more than my lathe. My VFD is pretty old now ~7 years the Vevor one may be different.
Great upgraded. Are you a concerned about the threads on the spindle side pully stripping off? I am thinking a counter bore insetting that retaining screw on the spindle to get more purchase on the threads on the back side spindle clamp would make sure it doesn't spin off in reverse or spin the threads when pushing it.
Cables should be double insulated, either use 3 core flex (extension cord) or corrugated conduit. Also cable looks to be 1.5mm, would not have thought less than 2.5mm would do.
I’ll bet someone already suggested this, but would the reason for (3) mounting bolts/screws for the lathe head is for leveling purposes? Another observation- in industrial plants it is standard that motors on VFDs are specifically designed for VFDuse. One reason is there are currents that flow through the motor and bearings that cause the bearings to fail prematurely. But I imagine this is not be an issue for a home shop?
Just from watching this series you have done, I see the need to use the mini for making upgrades to your setup while its still a running and operating machine... you should with patience be able to make a higher quality machine for tooling with the old one as it is now... Keep it in fair condition and its chance to do something maybe in the future that was unforeseen possible
G'day! I'm thinking about a similar upgrade but to a larger wood lathe. I realise that I'm asking a very open question, however, could you give me an idea of the Min and Max speed. Just a ballpark figure if possible. As standard my machine can run 50 - 3700 rpm over 3 ranges.Thanks in advance.
I see some very cool results from your personal build tooling, I was definitely wincing on that 2mil cut though lol Great upgrade so far, even if you didnt do anything else the variable speed and the power increase will be a huge game changer for future work. Thanks for sharing ...Oh and very pleased see that it didnt spiralise lol
![MINI LATHE TRANSFORMATION! DC motor to an AC motor 🔧 [Optimum D180x300]](/img/n.gif)
Tune in next week for the dramatic conclusion. Already up to 3mm DOC in steel and I can definitely push it further. EDIT: Alright the internet convicted me to change the wiring, no need to comment further. Also the wring is already delta, you can probably see the connection terminal in the top right corner at the 16:36 mark. See you this Saturday
Why did I suddenly have an image of a mini lathe whizzing round it's spindle? Lol
Nuts 😂
Thanks for posting this, I was pondering this idea 💡 myself. I'll definitely keep an 👁 out for the conclusion video 📹 🙂 👌
How long until the bed is bent?
I think that, as of now, the limit is where you say it is!
We should all pitch in and get this gentleman a band saw, I've seen him use a hacksaw in his videos more than I've used one my entire life. Great content 👍
But it's good for him. It makes his arm tired.
He's just doing that for exercise.
I agree, or have a raffle.
I'd Chip in some greenbacks
I just want him to address why he hasn't got a band saw yet
This has to be the most up-graded mini lathe to ever exist.
It's pretty modded..... But RotarySMP's version is also really well done - th-cam.com/play/PLHRtJd1bD3IQU-A-CPBwys-tTM3wKMOGW.html
Nah not enough it needs a hydrostatic way or somesort wear is our worst enemy.
@@woozhi9218 yeah but he could probably buy a new bed so cheap for the mini lathes
Nah. You should have seen some of them on the old newsgroups boards.
People have done some NUTTY stuff.
@@woozhi9218 imo, stiffness. Stiffness is the biggest issue with these tiny lathes. When you get a motor with real power it twists these lathes like a noodle.
At 3:31 I totally expected you to say "I also can't stress enough how much it feels like a blue monster staring back at me". Those cable glands look like eyes!
Yes cookie monster
Hah yes, I was thinking the same, and wondering why I had not yet seen a cookie monster comment.
@@BaldyTron the monster craves chips. Fat, juicy, deep depth of cut chips
Swarf Monster!
Glad it wasn't just me 😂
Nice! I run a 2HP 3 phase on my mini lathe as that's what I had spare. You need to operate the VFD via remote, you can probably use the controls already on your lathe for the variable speed and forward/reverse, it saves having the VFD near the lathe and getting it oily with your fingers. Steve Jordan did a great video on doing it.
You only need an on/off switch, a direction switch, (You can combine both and use only two wires, and a potentiometer to control many VFDs. Add some safeties like the emergency stop and you are done. Keep the control box small voltage and current, and any actual power switch in a dedicate box with the VFD. Add RJ45 connectors at both ends, and you can place the control box whenewer you want. If you need more wires, use DB15 or DB25 connectors. Remember to keep the start/stop intelocked swhitch in the main power. You dont want the power going out and the lathe to start itself when it returns.
Great work. Got to say it's equal parts fun and scary to watch 😁
One of the more practical reasons to use an over-size motor, is that you can still get ample power out of the motor, even when it's running below rated frequency. This makes the single belt/pulley position a lot more usable than it otherwise would be. Good stuff.
Love it!
I own a chinese mini lathe and one of my biggest complaints is the very low torque at slow speeds. I replaced the fuse with a circuit breaker and will overload and trip it when I'm trying to torque up on something at a low RPM. One must keep a meathook on the speed control to pull this off.
It's one of several reasons that I'm on the hunt for a used 'big boy' lathe. Not only can I handler larger parts which has been another problem, I can get higher torque at lower rpm. Of course a motor swap out like this is another solution but I'm going right to a more complete solution to the shortcomings of the mini lathe. Don't misunderstand me. I've made a lot of great small precision parts with mine but if I had it to do all over again I would have bypassed the purchase and saved my money for a better lathe. I've also spent a fair bit of time making improvements to the mini lath.
Hindsight of course always being 20-20.
When you did not use a hacksaw to cut the steel plate, I felt a great disturbance in the force.
Wow, what an upgrade! That is like a V8 weed wacker!
I have a 15" swing gear head lathe that weighs 2300 LBS (1043 Kilos) and it uses a two speed, three phase, 3 HP motor. With that much power, depth of cut no longer becomes an issue for the hobbyist. Your new problem will be rigidity and damage if / when you make a mistake.
I love the creative solutions to your problems, thank you for sharing.
Damn,I really ran the same thing with a 0,3 hp motor from ASEA motors(came with an old twin spindle attachment that was sexy enough at the time for me but while the whole contraption came as a "vintage" ARO drill mod 76** C,just for $460 while the brand new attachment from Rand Ingersoll costs about 4500$ alone so I took the deal of course!)-so it is obviously enough for an amateur machinist..Meanwhile I never understood why ever since 1980-s those "pneumatic auto feeders" are almost as expensive as they were yet barely anyone still uses them and their attachments are still produced by different companies and yet I see some of them on eBay for quarter of the price of the new..So anyway I just bought a real monster of a drill as an investment/for the ridiculously powerful 25hp motor that it has..And the only time I used it even to a fraction of it's power(BTW it has a 4" stroke,it's vertical and has a twin spindle attachment with 2×13mm chucks size)-it drove two carbide bits through a 5cm thick titanium piece without even slowing down,or any effort-and the whole thing is just over 120 lbs with motor and manual control unit,pneumatic self feeding system,cooling system and the rest..Just 10 seconds,one stroke,3900 rpm,air cooling selected-just a nice fire show of turnings and the drill just retracts up in less than a second..Isn't that insane?Nearly overloaded the grid of an entire house and according to the manual it can draw up to 1040 amps at 24vdc so quite serious even for a machine shop..Probably would easily power an entire array of similar drills along with a number of other automation systems,pistons and other stuff..
I can't believe I bought the same motor , well a 1.5kw 2hp version. I was thinking about the 3hp one but chickened out.
I fitted it a week ago and I'm loving it, great motor and what a price.
Love the logic 'three is bigger than two'
Glad you explained why your using carbide tooling, makes perfect sense when you have enough power and can't get low rpm.
I have wondered what would happen with a two hp motor as I just happen to have one, going to three is total overkill but great fun.
For brazed carbide, use a Dremel and a cheap Chinese diamond bit to re-shape top cutting edge for aluminium
But you do not have the rigidity in the machine itself.
I must admit I missed seeing the hacksaw in action when cutting down your 20mm flatbar to length.. I doubled the HP to 1hp on my small scope multi function machine and it made a big difference, 3hp is going to be interesting!
Two things I learned from welding classes: #1- When welding two pieces of steel like you did, grind a groove into both sides before welding to make a more solid weld. #2- Flux spray EVERYTHING to be welded for the most reliable and strongest weld possible!😊
Have you checked the alignment of the bed after bolting it down to a piece of 20 mm hot rolled. Just a thought?
Not yet, Its always been a little out of whack, so correcting it will just be moving the shims around
I'd Artisan Makes had a Patron with Blueprints to his Designs/Upgrades, I'd 110% be a happy and loyal customer ! I love everything he does.
my god. that thing is a real beast now. I have one of these 7x12 mini lathes, but I have never considered going to this level of extreme. I don't think the 42" toolbox that I have my lathe bolted to would be able to handle that level of upgrade.
Man, you outgrown your lathe many projects ago. Awesome work.
LOL I thought putting 2HP on my Seig C6 was going to be overkill, however Im thinking of getting a 3HP one now to replace it and using the 2HP for my belt sander im building, thanks for all your videos I never miss one, as your are running pretty much the same kit I am.
Thank you very much for sharing your creation. In my mini lathe I made smaller motor pulley combined with bigger input at middle pulley and smaller output in the middle pulley also, if I needed i could have made a bigger and shaft pulley but didn't needed, it just became powerful enough too burn cutting tools and the lathe won't stall. The lathe has two set ups 1) 2500rpm that was useless for me. 2) 1250rpm which was good but i wanted more torque. Now after pulleys mod it runs 830rpm max and it's good enough speed with very good torque and it stalls only with parting tool sometimes. The pulley grooves was a perfect match with metric thread cutting tool for my mini lathe.
Just a thought - The three screws may have been intentional to avoid warping, since 3 points define a plane and the 4th may be over-constraining. Not sure if that applies here given all of the mating surface, though.
Possibly. However similar type lathes have 4. Mine does. Seig type. Vevor model. Sometimes they are lazy at the factory. You'll have bosses that aren't drilled and tapped yet should be. Missing screws, metal shavings in the headstock, Sand in the headstock....etc..... Good ol Chi-nuh.
I've got an old hafco al51 and the first thing I did was exactly this, a 3hp 3phase with a vfd, and I used two peices of 6mm flatbar under the lathe which made it easy to get the bed leveled.
A lot more rigid than my old mini lathe and capable of far greater doc than would ever be done in practice. Had it taking 6mm doc in 6061!
The ability to run more speed is nice which is great for the carbide I use, unfortunately not so great for vibrations due to my mounting
I've got the same lathe, would like to see that motor setup.
I have the same lathe as well. I just put a 2hp 3 phase and it's not bad but these videos make me wish i went for more. I am currently machining a replacement for the compound because it's flexing and wobbling all over the show.
I wonder if you have the same crappy design and how you fixed it? It's just a thin plate held on with two small bolts that go into the T-slots. It's handy to have the compound but I am trying to eliminate as much flex as I can
Apart from that, so far I really like the Lathe.
4:49 For a moment I expected you to cut it with a hacksaw as usual lol
he had us worried for a moment :o
Funny, I did a similar modification to my minilathe a few years ago. I'm curios to learn how you will solve the upcomming problems.
That's ominous! Tell us more!
Be careful with the motor cooling while using VFD's .
If you plan it to run a lot of time under ¿40 % - 30%? frequency the motor will burn after long sessions of use.
The reason being the stock fan (mounted on the motor axis) is designed to keep it cool it at 100% frequency .
Half the speed you around half the cooling (but not the heat ! it's more inefficient running it with an VFD!).
For short sessions it should be okay.
Or look for Forced Ventilation fan kits .
Those have the fan with their own independent motor .
Its a 900 rpm motor, so its generally being run close to its normal speed. And for what it's worth, its not drawing a huge current, definitely no where close to 2kw. I had it running in today and for an hour or so in some 4140 and whist there is some heat being produced, its not close to being something i'd be concerned about.
That motor is Cookie Monster. I'm sitting here thinking how much it looks like Cookie Monster, and then here comes an Oscar the grouch mug on the screen suddenly, and it's like I'm on the set of Sesame Street.
Love this build. As others have noticed, the spindle locking nut sits quite far back due to the wider spindle pulley.
To get more threads engaged by the spindle locking nut, you could machine yet another spindle pulley larger in diameter to accommodate a large diameter counter bore for the locking nut. The counter bore would be just deep enough to allow the nut to engage all the threads.
Of course this restricts access for a spanner wrench, so that problem would need to be solved. An offset wrench, or a pin style wrench might solve that issue.
Of course the larger pulley gives a slower speed for the same motor rpm, but that might not be an issue. You could always change the motor pulley if that even made sense.
It’s sat like that for the past 3 years. It’s always been one of those things I’d get around to doing. Like a custom nut but never had to time to. But hey it’s never been a huge problem. Yet anyway
@@artisanmakes I suppose as long as it feels safe, there's no sense fixing something that isn't a problem.
You're a better machinist than a lot of fitter turners I've met over the years.
nice work.
I quit fighting my mini lathe and just went with a 10x22. the biggest headache ive had is putting it on a wooden workbench. everything else has been gravy.
To get slower speeds from a drill press you need to use the spindle of the drill press as a countershaft. I'm doing that, i got a central machinery 5 speed drill press and it has a 2/5 HP motor, better than 1/3 and not as good as 1/2. If you use the spindle as a countershaft then you can gear it down more and get more torque and slower speeds. The slow speed on the drill press is 760 but using the spindle as CS I get half that on the lathe. I had to take the spindle out and turn down the part where the chuck goes to 12 mm then I got a 17 tooth timing pulley with a 12mm bore, that is the same number of teeth as the lathe motor came with. The nice thing about that is that you can use the whole drill press head casting so it's all lined up. Then you just need to come up with a slide for the whole assembly for belt tension.
Next step - put stepper motors on the lead screws and turn it into a CNC lathe. There are some low cost GRBL control boards that you can run it with.
If you don't wanna wire up the VFD you can have a servo motor controlling the knob directly xD
The inhale i made when you pulled out that plate o' steel thinking you were about to hacksaw it.
I still have mixed feelings :D
I have just installed a 2hp 3 phase motor with a VFD on my Clarke CL430 lathe replacing the 3/4 hp single phase motor . I only used 2Hp because a used one came up on eBay with a quality KBAC inverter. It was a bit of a challange to get the motor to fit the existing adjuster plate and get it all lined up. It is now so much better to use with 170 to 1700rpm without swapping belts.
This is like shoving a twin turbo v12 in a citroen 2cv. Amazing.
Fair bit to discuss here.
Firstly, I have a minilathe as well - maybe slightly bigger than yours (what would be considered a 7" lathe, but has more mass) - I run a 1.5kW 3ph motor - but I wire it in 415v mode ("Star " aka "Wye" configuration) on a single phase 240v VFD - I can tell it's the same as how I saw how you have wired yours, where the resulting power maybe ends up around half that, and this is more than enough to perform huge depth of cuts, but you're still in the "grey area" of snapping cast iron in half if you crash it. DO NOT WIRE IT IN DELTA CONFIGURATION - that would remove all doubt to causing permanent damage.
Next, with VFDs, the lower the frequency, the higher the current draw - now you've wired it in star config - which is a good start as the coil resistance is increased, but you should be cautious of running the motor under 20Hz - there is a small risk of blowing up the VFD (recently happened in a FB group I'm a member of), but that risk is lowered due to the star config and 240v input.
If you read the VFD manual - it should have a "Max current" setting - good to set to the max rated current on the motor's spec plate + 10%, and "Minimum RPM" (Set to 15-20Hz). Max RPM is typically 80Hz before 3ph motors begin being inefficient, but if you're finding yourself at 80Hz and wanting more - you should probably redesign primary the pulley ratio, or add pulley ratio options so it requires a belt change, 95% of your work should be within the 25-75Hz range without any belt change.
Some other VFDs can also display "Alternative RPM" (by using a multiplier against the frequency) - so depending on your pulley setup, you can have it read out true spindle RPM instead of just the 3ph frequency. I never got around to doing this on mine and have come to know it intuitively, but might be beneficial to you if you get this set up before you end up getting used to it, like I have.
With bigger depth of cuts, more RPM, more power - come more heat. It's time to invest in a "mist cooling system". They're $30 on eBay and need a 30psi air feed and (ideally) a source of semi-synthetic coolant mix (or plain water at minimum). It's either that, or you'll continue to burn out your carbide. I'm very much like you in that respect - just preferring to use carbide, never had HSS - but you'll find that has it's limits as well, so do yourself a favour and get a coolant setup going.
Next, consider a diamond wheel setup where you can touch up your tools - a couple of 6" diamond wheels is $150 on eBay (600 grit, 120 grit), and makes for another decent project + learning curve to build the sharpening station and technique to use it, to optimise your lathe work. A properly freshened-up, mirror-finished brazed lathe tool is really something to behold.
Love your work - as I continue my own journey somewhat in parallel to yours.
Cheers mate. For what its worth, the manual for the VFD states to use triangle/delta for the wiring and not to use wye. Doesn't look like I'll be going below 20hz for this motor, unless in reaming or threading. Already looking into a spray coolant, the work is really heating up with these cuts.
-All 3 phase motors are wired Delta even when you supply them with y like 120/208y. Delta is a phase to phase reference and y is a phase to ground reference.
-amps will go up with load not frequency or cycles.
Why is there always some nuffy contrarian who insists on posting unhelpful drivel.
@@LitchKB Because this HELPFUL drivel is actually correct.The voltage specified is 240/415, which means a single winding should not exceed 215V. Using delta on a star motor will result in too high currents and thus irrevocable damage.
There is only ONE exception and nobody ever tried to explain it properly. Which is the case of single phase to three phase converters. The voltage between phases will become 230V instead of the normal 400V you would normally get from real three phase power.
@@patrickd9551 out of context morons arguing points that were never made is unhelpful drivel.
The spec plate will show the voltages and wiring configurations. Simple. That, in addition to using VFD current and power limits is how it's done.
No on is telling anyone to wire the motor in delta with star voltages, so again you're just another nuffy arging with a point that was never made.
Great vid. The most important part of this motor is the colour. The blue looks great!
Wow Bold move with the 3Hp. It's nice to have variable speed capability but safety must come first as this motor will put so much torque that the spindle and chuck may suffer. We would all like a lathe to cut deeper and faster but there are limits to all tooling and a 2mm cut for this type of lathe is very good. As machinist quality of manufacture should be our objective at the lost cost possible. Looking forward to your up coming builds,
Captain! Hull integrity at 24%!
For a 3 phase electric motor to run on 230v you need to connect it to Delta configuration, I guess you changed it up after all.
Yes I did, almost forgot to change it to but it is laid clearly out in the vfd manual
I actually have a 1.4KW three phase motor attached to the minilathe, new from the factory when I put my hands on it. Salvaged from an industrial diswasher broken water pump. If you know where to look, it's not dificult getting this kind of motors for free, even new ones. I must recognize I have it very easy, I'm the head (and only member) of the returns and guarantees department of an spare parts seller for hostelry appliances. I just need to pick what seems interesting from what I send to the trash for reasons like damage during delivery and not economic to repair. I have more monophase motors at home that I can use in my whole live, a wide range of powers. :-) (And some nice three phases ones). But seriously, learn where to look for these motors and other parts. A lot of industries dispose of perfectly working motors because the part they are part of have some flaw that doesn't affect the motor and is not economic to repair.
I love the idea, and I always see your videoes, keep up the good work!
When it comes to motors, you should look more at torque than HP, but it is very common also amongst car and motorcycle enthutiast, that the relation between torque and hp is misunderstodd or forgotten.
Torque can be stationary, torque does not say anything about movement.
HP is both torque and movement in the same designation.
That means that hp is both torque and rpm in the same designation, where torque is only a force.
To compare motors, you need to know both the hp, torque and the rpm, because on the lathe you will gear it to suit the rpm with pulleys.
You have chosen a 900 rpm 3 hp motor, that motor have 22,5 Nm of torque and comes in a 112 frame - no wonder you think it is big, it has the same torque and frame size as a 9 hp motor that runs 2800 rpm.
That is a lot of motor for that lathe 🙂
All that said, I have 4kw 27 NM 1400 rpm motor waiting for my 13" lathe, just like you, I don´t want to fiddle with belt and pulley change.
I don´t know if I can post links, but here is an easy chart, where you can compare motors.
www.seipee.it/wp-content/uploads/2019/03/Motori-Standard_JM_GDM.pdf
That's pretty neat. It will be interesting to see if you can resist the urge to push the lathe til something fails. Hopefully not. I almost bought a used chY-knees mini-lathe that had a motor upgrade done to it. The seller was selling it without the motor for only $100 usd. Everything else seemed to all be there. I inspected it carefully and noticed that the bed had a slight twist in it. I assume it had a sudden stop/bind that did it in. Just be aware. Good luck.
When I seen that bit of plate I thought holy crap! And then you said that you were going to cut it down to size. 🤣 Then I thought, how on earth is he going to cut THAT?
That's a gutsy effort cutting a bit of 20mm plate with an Ozito 4" angle grinder. Then you backed it up and did it again. GO YOU LITTLE AUSSIE CHAMPION!
Have you thought about putting a recess in the spindle pulley so the nut gets a little more purchase on the threads?
I know you are probably going to anyway. You really should have double insulated wiring for the motor. Because safety.
And some proper start stop switches with a magneticly latched E-stop. That thing has decent power now.
Will be good to see what can be done with that machine. Nice one.
Man that there is awesome. Over here in the u.s we use commercial sewing machine motors. Most of them come with a variable speed controller and produce a insane amount of torque and be 3× smaller than the 3hp motor you used. The range on most of the sewing machine motor is 100 rpm up to 4000 rpm. Even though small chucks aren't rated for more than 2500 rpm max 😂. Glad to see the upgrade though man. You may or may not be familiar with the guy, but his name is ade. His channel is Ades workshop. That guy is super smart with mini lathes as well. Might be worth your time looking into his channel and gain more knowledge or ideas for your shop.
I would not have thought a sewing machine motor was suitable. They are series-connected universal motors, which means their RPM is inversely proportional to torque. This means the chuck rpm will vary a lot depending on depth of cut, turning radius, etc.
Also, they are not designed to work full load for any length of time - that's why they can be so small. A lathe will make the motor work CONSIDERABLY harder than a sewing machine will.
@@keithammleter3824 have you looked at the power of a commercial sewing machine motor? The materials those thing have to push a needle through, there's no stopping that thing nor slowing it down. For a mini lathe, there almost perfect match.
Ive seen a few people attach them. From memory servo motors no? I looked into it a while a back but went with the 3 phase.
@@artisanmakes yes that's what they call them servo motors. That's cool part about mini lathes you can use just about any motor to run them as long as it makes decent torque.
Also called consew motors, I have a 1hp one on my lathe with a small 4 rib belt, has a serous crash a few months ago, and it smoked the belt instead of stalling the motor.
16:30, i'd take a look at the wobble on the pulleys. That could end up bad if you're pushing the lathe and the motor puts too much torque on the spindle.
Also those welds for the baseplate for the motor looks like an extra safety feature for over torque :D
Also also, watch the temperature of the motor when using it at low speeds and pushing the motor. The VFD only changes the frequency, not the amps, so the motor will still use a lot of amps and with the low speed, the fan would have less effect because it's directly connected the the rotor.
But great video and hope to see more niece upgrades for the mini lathe and mill.
The threads themselves are a little eccentric. There’s not much that I’ve ever been able to do about that. The heat ain’t much of an issue. We aren’t really using that much current to take the cuts, at least nowhere near the motors rating
The current drawn depends mainly on the mechanical load applied. The no-load current is very low, only overcoming friction in bearings and belt, plus any fan loading and windage. Available torque drops significantly at low speed, mainly because the frequency slippage (ratio of applied to actual) is limited- this reduces the current taken.
@@Tensquaremetreworkshop Along the lines of this, I measured the current draw from the wall and it is rarely going over 1000w. All in all the heat is not so bad and very manageable
Yes finally, i was asking for a 3phase motor for so long.
Pd: i was expecting the hacksaw to cut that big bar
I was expecting the same. Mildly disappointed actually.
@@vaulthecreator I'm very angry he didn't use the hacksaw, thinking about unsubscribing 🤣🤣
@@ferrumignis 😆
Be careful to keep the motor cool at low RPM. You will probably need some kind of fan to cool it.
Not really, those 3 stallions wont break a sweat on this machine... 😏😂
@@peterfitzpatrick7032 It is not the load of the motor that is the problem. Problem is that motor still gets 2,2kW of energy, but slower RPM is also on the fan that is cooling the motor and this way motor does not get enough cooling. Believe me, this is problem for this kind of setup.
@@Slemi The motor will not "draw" 2.2 kW unless the torque is at the maximum allowable level. The VFD varies the current depending on the load. You're still correct that the fan will be less efficient at low speed, but it's not as bad as full current and full voltage all the time.
Amps go up load. Heat goes up with amps. I’m no expert but I can’t imagine and kind of sustained load that would cause an issue.
Eh, nothing an RPM-triggered blower fan a few inches away from the motor fan intake can’t handle...
I mean something like ‘if rpm below xx, fan ON, else OFF’
I've been thinking about taking one of these and doing an upgrade series. Starting with the small mods, eventually casting it in epoxy granite and bolting it to the bed of my 10hp Daewoo. And of course, running a driveshaft to the spindle of it to have a 10hp minilathe. Maybe someday haha.
Cracking me up that the motor is bigger than the headstock 😂
Why is the pulley on the lathe shaft wobbling? That could damage bearings or give you uneven finish on the parts. Also, I noticed to provision for belt adjustment.
Hi, did you find that the belt connection direct to the spindle pulled the spindle? Thanks Patrick
You seem to be doing exactly same steps I did with my lathe. It's bigger and came with 1.1kw motor. Next phase would be to make variable transmission which uses scooter belt. It's quite simple since ratio is manually adjustable. It provides much better stability and torque on low rpm's. It have clear influence on surface quality.
By the way, in your setup, you must add separate cooler for your motor. Otherwise you burn it with low rpm.
limiting factor on this mini lathes are the headstock bearing, spindle and casting size/thickness/intended duty and the bed/crosslide widths. Interesting experiment nontheless.
Trampo top demais
Maquininha ficou show
Saudações do Brasil !!🤝
With increasing your lathe’s power you may also want to consider taking a look at your tool post. In many tool post systems the sizing is determined by lathe power, presumably so it doesn’t break.
The multifix style tool post I was recommended by the spec sheet for my 3kW lathe is surprisingly big. Maybe consider a faceshield in the meantime ;)
The manufacturer says the tool post should be okay. Doesn’t help that I’m the manufacturer for the tool post though.
@@artisanmakes Lol! Waiting eagerly for the next video.
@@artisanmakes Keep eye out for developing cracks in the casting now that you have lots more power and more over temperatures of different parts. On glance those wires going from VFD to motor seemed bit thin. My unit is way smaller and need 2.5m2 wires, those looked like 1.5m2.
Also since its lathe and there will be wire spaghetti, you might want to add wire cover and strain relief for the cable, well as prevent any of those going into wire port and touching up into the poles. Unlikely event but its tool and anything can happen and you dont want sparks flying or shorting the VFD if spaghetti catches on the wire for instance. Dont get me even started with the metal dust. Belt cover and boxing the VFD with remote control box would be good addition as well. We all know those are not cheap so might as well go extra mile protecting it.
Have you changed the motor connection from star to delta ? You won't get full power with vfd without it. You need to turn 3 bars in the motor terminal block
Yes I did, almost forgot to but it is laid out in the vfd manual to use delta/triangle only
You can bolt a plate to the headstock. And connect it with a thick metal piece down to the table. It would be more sturdy and have less flex when turning harder steels.
I think the headstock was way too small to be bolting that much to it. In any event I don't think there was much left to come out of it, regardless of where the motor was bolted
Holy mackerel! This amazing upgrade is like putting a V-6 into your electric toothbrush! Daa-um! Great video!💪💪💪
Very cool upgrade. I have the same issue with my lathe.
I plan on using a sewing maching adjustable speed motor - and yes, motors prices have gone through the roof!
With the money spent in this video, you could have probably bought a bandsaw instead 😅
Didn't read all the comments, so I'm not sure if someone already said this, but when running a VFD from single phase, you need to de-rate the VFD by 50%, so you need at least a 6hp VFD to run a 3 hp motor at full load on single phase
You say you've fitted a 3hp motor to your mini lathe, but I think it could easily be argued that what you've ACTUALLY done is fitted a mini lathe to your 3hp motor ! :D
Yes, a bigger motor is definitely an improvement but I see this more as a way to get a more stable speed than doing heavy cuts.
With a big motor, you risk damaging your spindle bearings, shearing off the compound slide (that you luckily already removed) or even twisting the bed.
My Wabeco D4000 mini lathe has a 1.4 kW motor which is what it comes with from the factory and I think this is still on the small side since the spindle speed varies quite a bit - especially on the start of a cut.
Soon you can fabricate a better bigger lathe then what you bought! Great stuff.
Looks like you should rebuild that drill press with the old motor instead of trying to drill thick steel plate with a hand drill...
It’s in the works but I just haven’t had the time to get around to do that. Plus the old big v belt got burnt up last year so I’ll have to order a new one
That new motor looked just like the Cookie Monster when he took it out of the box 🤣🤣
I was always told to go about 10% over on VFD's and more on chinese ones but i take it you have a good supply to your house/garage so its probably not a big deal (Also worth checking how balanced the lines are into the motor underload cause they can burn out quicker similar to running them off rotary phase converters)...
Only real word of advise i can give for having that much power is having a safety guard and the use of steady rests etc because if a piece slips out it will do real damage ( I have a hercus 9" i had this upgrade on but went back to smaller motor when i brought a big 7hp turret lathe..both will kill without a 2nd thought)
Awesome work and keep it up :)
That’s very interesting. Never head that, I might have to look into that. Cheers
You should make yourself a small power hacksaw. I used to have one that took 10” blades, could do whatever size blades you use. It would only need a small motor and save you a lot of effort on cutting your stock. Done right and it would always cut super straight as well. Wouldn’t always replace the hand hacksaw but would be good for cutting bar stock
I think his limitation is space for more machine tools rather than a reluctance to buy/make them.
Also if he had a powersaw he would loose 1/2 the comments in every video. That is no good for the algorithm!
@@cobre7717 - note he never replies to the bandsaw comments either 😂
And here i thought i was wild for sticking a 2hp single phase on my 10x30 benchtop lathe...
Regarding the wiring, I highly recommend using thicker gauge wire. And also, you SHOULD connect the earth wire to the lathe.
When you first showed the new motor, all I could see is Cookie Monster
When you first opened the box, I thought the motor had googly eyes on it.
That’s the same size motor as my 13”x28” southbend! And the same exact vfd. Benefit of the bigger lathe and gearing is rigidity and depth of cut. Biggest cut I’ve taken is .300” /7.6mm. Only because I ran out of cutting edge on my tool
I liked that 3 phase vevor converter
That motor has wires coming out of it's eyes!!!
As long as the spindle and bearings can handle it, no motor is too big 😂
You probably need a belt tensioner and a V belt that's fully wrapped, otherwise you're going to get black belt residue everywhere.
Already co-opted my machinist jacks as a diy tensioner
@@artisanmakes that's a clever idea!
Nice work on mounting the motor pulley.
Regarding only 3 screws in the head stock, could it be to avoid potentially warping it if the 4th point isn't perfectly planar?
Maybe but most non sieg brand mini lathes use 4 bolts in the same pattern I used
HotRod- lathe: Thanks to the VFD that big motor can always be dialed down, you can get off the throttle in a V8 but you cant get V8- power from a threebanger :)
You can't reduce the speed with the VFD by as much as you might think, because the lower frequency increases current drawn and also significantly reduces cooling in the motor.
Congrats on the upgrade... of your hacksaw...
Just saw your video.. I installed a 3hp (2.2kw) motor on my 10"x 20" lathe and I was wondering if I should use a smaller unit to save some space... then I see you have installed on a mini lathe.
Anyway you can limit the power in the VFD and the bigger motor will have better low end torque so you will get the full power up to the limit in the VFD right down at low RPM.
Great Job, that's the Aussie way if it is not powerful enough add a bigger motor will be good to see how it goes next week.
I am putting a 2.5 HP motor on my mini mill . It has a 3/4 HP on it now but I have a need for more power .. I bought the 4 inch vice you have on you mill .. going to put it all together soon .. I think 3 HP is fine as long as you don't push it to hard .. I enjoyed , thanks ! Hey , I would enjoy more go kart vids to ..
I have watched this more than once, very exciting.
I did a 1hp 3 phase with VFD about 8 months ago. Best decision ever. You'll not be disappointed.
Does the VFD have an output to connect a potentiometer? It's a great way to control the rpm, also a hall effect tacho is great to read spindle speed instead of calculating any gear reduction or multiplier you have in pulleys.
It is in the wiring diagram that it can be connected to a potentiometer, and there are connections for one. I just havent gotten around to doing it yet.
Cool and everything but no hack saw for 20 mm plate?
You need to change the motor wiring to delta. Check inside of the cover plate / manual. Star is for 415v 3ph. Your vfd only outputs 240v 3ph, which means you need the motor in the delta configuration. I'm currently doing the same upgrade, 2hp version of that motor.
Kinda difficult to see but I did change it to delta, around the 16:24 mark. cheers
which belt do you use for the new motor? I still need to upgrade the belt of my lathe because it's slipping too much. I have a 1.5hp motor attached but it's worthless due to the bad belt.
how are you going to use back gears or power the lead screw?
You are going to have a lot of broke tools and possibly a broken lathe as well. Just think of the tourque with the machine in low gear.
My 5.5 in center height Colchester Chipmaster had a 3hp motor. That machine was a heavy duty production machine tool that weighed half a ton.
Careful with the vfd - they are great, but most induction motors are meant to spin at a specific rpm so you lose a lot of cooling at low rpms. The other thing to keep in mind is that when you use gearing to reduce rpm you multiply torque, but when you use a vfd you lose torque the lower the rpm you run it at. Some people have trouble with stalling at low rpms.
You probably already know all of this (if I remember right your old lathe used a very noisy vfd)....
Its a 900 rpm motor, so its generally being run close to its normal speed. And for what it's worth, its not drawing a huge current, definitely no where close to 2kw. I had it running in today and for an hour or so in some 4140 and whist there is some heat being produced, its not close to being something i'd be concerned about.
How do you adjust belt tension?
Also please peel that clear film off the lathe name plate!
I was disappointed with my VFD. I have an old but much bigger 3 phase lathe and bought a 4kW VFD as, like you, I don't have 415V. Turns out the VFD is not big enough as it only puts out the rated power if you input 3 phase - otherwise divide by power at least 2. It also puts out 240V per phase not 415V, so I had to rewire the motor to delta configuration. The VFD overheats and trips out if I push it. In the end I went the other way, removed the 3 phase motor and replaced it with a single phase motor, it's much better, even if it has 1/2 the rated power of the original 3ph motor. In your case I think you will be OK, as you started with a low powered motor and the higher reduction via the pulleys will make a big difference with the higher torque. I hope the power at the high speeds are not adversely effected, and if it is possible on your motor, it might be best to rewire it to Delta. I enjoy your videos - keep it up and good luck with the project.
My physics is really rusty, but...
A 3 phase supply is 415V phase to phase and 240V neutral to phase.
In his street there will be 3 phase power. His house will just be connected directly to neutral and one of the phases (and his neighbours to the other phases in an attempt to keep them balanced).
@@georgescott6967 What you say is true but my VFD is 220V between phases not 415V. At the time I bought mine, VFD's were available with true 415V but cost more than my lathe. My VFD is pretty old now ~7 years the Vevor one may be different.
I saw the notification for the motor upgrade and the first thing that came to mind was a spiralised lathe ......
No scrap and cheap parts. That's what I like to see. Do it well or don't do it.
Great upgraded. Are you a concerned about the threads on the spindle side pully stripping off? I am thinking a counter bore insetting that retaining screw on the spindle to get more purchase on the threads on the back side spindle clamp would make sure it doesn't spin off in reverse or spin the threads when pushing it.
Cables should be double insulated, either use 3 core flex (extension cord) or corrugated conduit.
Also cable looks to be 1.5mm, would not have thought less than 2.5mm would do.
My bad on the first part but the cables are good for the current load
1.5mm is more than sufficient for 15A per phase.
Just one question, why a cogged belt? why not a normal V belt?
I’ll bet someone already suggested this, but would the reason for (3) mounting bolts/screws for the lathe head is for leveling purposes?
Another observation- in industrial plants it is standard that motors on VFDs are specifically designed for VFDuse. One reason is there are currents that flow through the motor and bearings that cause the bearings to fail prematurely. But I imagine this is not be an issue for a home shop?
Just from watching this series you have done, I see the need to use the mini for making upgrades to your setup while its still a running and operating machine... you should with patience be able to make a higher quality machine for tooling with the old one as it is now... Keep it in fair condition and its chance to do something maybe in the future that was unforeseen possible
G'day! I'm thinking about a similar upgrade but to a larger wood lathe. I realise that I'm asking a very open question, however, could you give me an idea of the Min and Max speed. Just a ballpark figure if possible. As standard my machine can run 50 - 3700 rpm over 3 ranges.Thanks in advance.
I see some very cool results from your personal build tooling, I was definitely wincing on that 2mil cut though lol
Great upgrade so far, even if you didnt do anything else the variable speed and the power increase will be a huge game changer for future work.
Thanks for sharing ...Oh and very pleased see that it didnt spiralise lol