how strong steppers are?
ฝัง
- เผยแพร่เมื่อ 5 เม.ย. 2018
- test on 2 steppers, nema 23 and nema 24 in cnc machine.
lead screw 1605 which is 5mm travel per revolution.
Driver gecko540,
Z - Dual Shaft Nema 24 CNC Stepper Motor 4Nm (566 oz.in) 60x60x100mm 8 Wires
X - Dual Shaft Nema 23 Bipolar 1.9Nm (269oz.in) 2.8A 3.2V 57x57x76mm 4 Wires - วิทยาศาสตร์และเทคโนโลยี
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This is what i've been looking for. Everyone keeps telling me calculate This and that, and you made it so simple. Cheers
Thanks for your video. I appreciate your real world measurement testing. I was surprised at how strong your Z axis Nema24 is.
Your build is amazing! I love the granite construction :D
My calculations were about 25% higher than your measurements, so you're right, you gotta meassure it :)
Thanks Piotr, way different than I predicted! Very nice. 👍🏼
keep in mind that steppers have peak torque as you approach 0 rpm. As you increase rpm the torque decreases exponentially. For example, your nema 23 has more torque at 5 rpm than my nema 34 at 500 rpm
Great point!
Same applies to Nema 23?
Ive done some calculations and im very glad this video confirmed it, thank you very much.
Great help as I'm currently searching for the most ideal motor for my DIY CNC built
great help . i never think about that much. shot and helpful. thanks.
Fantastic! If the scale reports fast, it would be nice to have a few measurements at different velocities. Looking forward to the "will the bit break?" video.
wow really nice I bought a nema23, but did not realize the power it has
The sound the machine makes when it creeks under high load sounds like when you browse through GTA San Andreas' menu.
omg yes
Thank you very much for your video, sir. I need this data for thesis. It is really helpful. God bless you
This is a real test, this allows me to have a clear idea about how much weight can I handle in a real world!
This is amazing. The torque is really high.
Love it,,😋😋😋
Thanks for the reply..have to agree with you as it makes sense.
pl make more videos on types of linear guideways/couplings.ballscrews-leadscrws and how to select them. you are too perfect and explanation is very practical. thanks
wonderful.... clarified all dobts . nice of you. pl make more ....
Era exatamente esse teste que eu estava procurando!! Muito obrigado. Saudações do Brazil.
Very interesting ! Thanks for sharing !
its really great measuring.
awesome man , subscriber from Egypt.
I realy like what you do !!!
Very cool video! When not operating the stepper motor, would the max load be much higher? For example, while the stepper motor is stationary, how much more load could the structure handle? (stepper motor powered off and something pulling the C clamp translating to the right). I'm thinking of using a stepper motor to lift up a wooden platform (think of a large 3D printer), so I'm interested in understanding how much load that platform could take with a stepper motor below it.
Very Cool.
Many thanks.
Firstly, thanks a lot man! It is exactly the data I needed for a project. Second, just for info, the stepper force would be even higher if you could apply the load in the longitudinal direction of the screw.
In your configuration, as in most machines, the direction of force tends to bend the nut and screw, hindering the sliding efficiency. I plan to make a DIY tensile tester with a Nema 23, but with a tube around the nut to pull the sample, so that the load does not bend the nut. I hope to hold even more than 200 kg, lets see !!
Very helpful test for me. Thank you so much 🤗
I'm glad it was :) thank you
Thanks for that really interesting and somewhat helpful ! I'm about to use a stepper to drive a mini mill for metal and was thinking of using a Nema 23 420oz which if I'm right is stronger than both of yours ? I'm not sure if I need that large but bigger is better in the metal world ! You must have faith in your machine build to do that test !
Hmm.. sure you can use as big stepper as you want. But I don't think you will use endmill in the size of your arm;) you don't put much force on the end mill while milling. Otherwise it will break, chip, deflect etc.. So going for monster stepper won't have any effect on milling. Perhaps it could run colder ;) or it could have so much power that at crash it will bend your machine or ball screw. So bigger is not always better ;)
Wonderful video thank you bro.
So useful. I am about to start buying parts for a new CNC machine (made out of 20mm aluminium plate) and I was tossing up Nema23 (like I have at the moment) or 34s... Clearly some middle of the range Nema23s are just fine! Do you have a thought on closed vs open loop steppers? I also like the look of the clearpath servos, but am sure I don't have a need for anything that flash
In my humble opinion, you should be fine with nema 23. Try to imagine you standing on a spindle with extra bag of the concrete to move it through milled material. Where vertically it might be not so bad but sideways it's just insane. Instant tool brake. Not mentioning frame deflection etc. Closed loop steppers are unnecessary for cnc. If you loose step and you need closed loop to bring it back to the position your part will be damaged already. So it's better to don't lose steps ;) one good thing of closed loop stepper is higher top speed and better acceleration. If you want to mill stuff faster than 3000mm/min then I would recommend closed loop. Btw faster you go, lower torque stepper has. I'm milling everything 1000mm/min it's fast enough and I take 10mm - 20mm deep cuts at once.
Hey plz make a video about the complete electronic setup of your machine... The circuit diagram, the component specification and all other stuff related to it such as setting the whole setup with mach3
Watched all the 'granite CNC' vids... really love the idea. But in this video I noticed you drilled a grid of holes in the surface plate. Any vid on that? Did you also glue threaded inserts in the holes? And how about cooling water/fluid that stays in those holes or are they drilled all the way through? And what about chips getting stuck in the holes? Just curious. Really nice build!!
those holes are done the same way as in previous videos. I thought there wont be much sense to make another video about drilling more holes :) inserts are glued just like any other inserts in my machine. i drilled holes 21mm deep for 8mm stainless steel insert. if i would drill it right through it would weaken granite too much. What about chips and water in them? i was worried about it myself. First test was to cover them with screws. but then heads are sticking out and make cleaning much more annoying. i could use grub screws to cover those holes. at the moment concept is not to worry :) then time come i will just use compressed air from the compressor to blow out whatever is inside. as long i won't put screw in clogged insert it won't compress chips beyond point of blowing them out. so far it doesn't look like its going to be an issue.
@@PiotrFoxWysocki Wouldn't it be easier to use the router as a drill? maybe with a drill instead of the spindle, but that would automate the problem.
Thank you !
thank you very much for this video, very useful. I'm looking at different motors for a project I'm working on which requires high torque, but never really found a video to visualize the actual weight being pulled by motors like you do. This is without gearing right?
5mm pitch no gears
@@PiotrFoxWysocki thank you :-)
Posiadasz jakies plany swojej frezarki?? Nagrasz film pokazujący sztywność maszyny ?? Pozdrawiam ;)
Very cool!
Muito bom! Este vídeo foi muito útil para dimensionar motores para minha máquina! Obrigado
Obviously, you don't want your machine to ever miss a step under load, I tend to set the stepper driver current just above that point, to limit the damage from a crash, and protect the ballscrews and rail bearings, and to let the drivers run cooler.
very interesting idea!
Great experiment that I've never seen from any build. Thank you for the clarification again. But the main question mark in my head is the Y axis which is carrying the most load. Are you planing to make a video about the Y axis.
I think this experiment is proofing the holding torque of the steppers with 5mm pitch leadscrews but the main concern has to be the inertia factor for your spesific build. And the way to measure your limitations on your machine is to write a G-CODE with difrent rapid axis movements and diffrent plunge depths, and run it with diffrent feedrates when cutting an actual material. this way you can find the feedrate that your motors stall when cutting.
I would love to see the limit speeds of this kind of a rigit and precise homemade machine on rapid movements when cutting. Thank you again and keep up the great work. Greetings from Turkey ;)
Y axis has 2 x nema 23 so we could assume that it can move 210kg (105kg per stepper) gantry weight is around 60kg. so i have 150 kg to spare.
i did some tests on the acceleration when i was setting up steppers in Mach3, my goal was to have it moving smoothly. i kinda settle with 3000 mm/min as my top speed. steppers are running on around 2.2 amps they could handle more but i didn't wanted them to overheat. anyway im cutting everything with 1000mm/min with maximum cutting depth of 10mm-20mm at once. and it just go like a knife through the butter :) greetings to everyone in Turkey :)
Thank you for your answer Piotr this clarifies my question marks, keep up your great work ;)
yeah stepper at low speed mad hard ) even whit smaller ones i used to brake bits 5 mm easy ) go whit 8 sure you brake them ) especially if go whit some force of inertia ) whill be fun to watch or when bit bites in so you got force of twist on mill bit and latheral force that might brake even 12mm ones )
Helped alot..thanks
good work
Excelent test!! Could be improved with a micrometer that measure the misallignement in case of non centered load applying due to beam affect.
my question is, is all this strength really necessary ??
how much force does it actually need to mill brass, copper, aluminum ??
I'm thinking of making a small cnc, and I would like to understand if nema 17 can be enough
Can you check deflaction VS the force applied ?
What is the holding torque set at though? Many machines wouldn't be at 100% current when holding so it might be able to take more maybe??
If I install a 1.7 Nm Nema stepper motor in my CNC, will it also be able to create a pull of about 100 kg?
so the 105kg is the nema 23..??.. how many microsteps you have on that motor?
is that using gearbox my friend..thank you
Czy ja dobrze zrozumiałem , czy to błąd w opisie pod filmem , na "zetce" masz mocniejszy silnik niż na "x". A ogólnie to dziękuję bardzo za ten test , jestem przed wyborem silników krokowych do mojej maszyny cnc i powiem szczerze nie myślałem że takie małe silniki mają taki udźwig.Wielkie dzięki za ten film.Maszyna wyszła super. Pozdrowienia z wiosennego Poznania.
Ano mam ;) że miałem 3 Nima 23 z chińskiej 40x60 cnc. To użyłem 2 na Y i jeden na X. A na Z mi zabrakło to wsadzilem co tam mi się w garażu walalo ;) pozdrowienia z jesiennej Nowej Zelandii ;)
I want replace my 3hp ac motor to stepper motor. Which stepper i should use
Czesc bardzo dobry film. Twoja CNC wyglada bardzo solidnie jakiej twardosci materialy mozesz obrabiac (tylko aluminium czy tez stal)
zrobilem ta maszyne z przeznaczeniem do robienia czesci aluminiowych, chociaz zdarzylo sie ze musialem cos wyciac co bylo stalowe o twardosci okolo 65r. wyciac wycielo z bardzo gladkim wykonczeniem. tyle ze do wycinania stali potrzeba spindla co sie wolno kreci i ma duzo mocy przy malych obrotach. a nie odwrotnie.
@@PiotrFoxWysocki czesc Dziekuje za szybka odpowiedz. Mam kilka pytan odnosnie cnc I czy bylaby mozliwosc rozmowy z Toba Skype czy what's up? Pozdrawiam Pawel
@@pawelgalecki2487 spoko. Dzwon na wazupa:)
Did you compare to calculated values? I assume you calculated axis thrust in the design stages, so was this test to prove the motor ratings?
no i didn't. i just used my educated guess based on my previous experience with steppers and fact that i had 3 nema 23 steppers from my previous machine. so i just used those. it turned out that they are more than enough so there was no point calculating anything. and if they would stall i would have a reference point of how much more power i would need. I wasn't to troubled by it because i have quite big stock of all sorts of steppers from nima 6 to 42.
What was the microstep config you had on this test? I read that holding torque decreases to around 70% at 1/8 microstep. I’d be happy with that strength... my leadscrew has 2mm pitch nema23 i have is a bit less than 1.9Nm but i have two of them that share the load of the axis i am worried about
microstepping was and is 1/10
My friend... why don't you use servo motors? there are some very inexpensive for sale in aliexpress. Or even steppers with encoders?
BTW what power supplg do you use? It has alot to do with the torque the motor can produce ..
as far i remember 48v 10Amp
Just curious what the strength of your y-axis steppers are? I'm building my first CNC so i have no reference as to adequate stepper strength, but im doing a steel/epoxy granite build so our axis are similar weight and my target top speed is only ~2000mm/min
Y are 2 nema 23 steppers just like the one on X axis. So over 200kg. Parameters of the stepper are in the description under the video.
Thank you :)
this is incredible , I always read " your gonna need giant steppers for that "" and its almost always false.
yeah same thing apply for saying need very ridged frame where if use propper coolant flood and remove vibratian by having your mill floating in my case its 3040 on soft rubber sponge makes aloot of better finish like my whole 3040 shakes like hell when cutting acrylic but makes finest finish but if i make it rock solid frame to floor than finish suffers
you need torque for acceleration. CNC jobs do not run in straight lines all of the time. Then stepper motors lose torque at higher speed. So if you want rapid speed you need powerful motors.
@@1pcfred the question being, *how* powerful is enough?
@@scottwillis5434 No simple answer to your question. You need a torque/speed diagram to make sense of what the manufacturer intended for that particular motor. The torque advertised by the manufacturer is the holding torque, which is of little use to you, if any. By and large, 300-500 rpm is the best compromise between not losing too much of a torque, having enough speed and stepper not getting too hot from continuous use. Between 300-400 rpm you can count on getting half of the holding torque. So, if you buy a 3,5 Nm stepper (holding torque) you can use about 1,7 Nm of REAL torque, at around 350 rpm. Now, if you need to know how much real/actual torque is needed to move a gantry, that is quite a challange to say for sure, because it needs some calculus of different parameters. Just as an example, about 0,003 is the coefficient of friction of either the ballscrews (no preload) or linear guideways, which means that with 1,7 Nm ,5 mm ballscrew pitch and virtually no acceleration (say 1 rpm of stepper) ,you can move about at least 3 tonnes of gantry for a distance of 1 mm in maybe 10 minutes ! This is no mistake: at least 3000 kg. There is nothing practical you can do with this figure, but it helps to highlight that once you want some acceleration, the game changes dramatically. The calculus is complex, but I can tell you for certain that with 1,7 Nm real torque (3,5 Nm nema 23 holding torque) and 5 mm ballscrew pitch you can move at least 300 kg of gantry, having a cutting force of at least 100 Newtons (you can cut steel with 100 N, and obviously aluminium too), at around 300 rpm of the stepper (which means 1500 mm/min cutting speed) and acceleration time of 1 second. The greater the acceleration time (which means the lazier the machine), the heavier the gantry that can be moved and cutting+friction forces to be overcome, and viceversa. Please be aware that in DIY setting the linear quideways will never be PERFECTLY parallel (hence the friction coefficient when moving the gantry will be greater than 0,003); the same goes for perpendicularity. So, the game changer is speed/acceleration. To give you an ideea, the torque that has to overcome the inertia is: Tj = Total moments of inertia (gantry, ballscrews, steppers) x angular acceleration ( which is angular speed / acceleration time). If you convert 300 rpm of stepper in rad/sec, you get 31,4 rad/sec as the angular speed; if you divide it by t=1 second, you get an acceleration of 31,4 rad/sec^2. With this value, you can calculate the torque that rezists inertia , by calculating the inertia of each moving element first. This torque will be added to the torque needed to overcome friction and cutting force ( Torque = Force of moving the portal and cutting the material x ballscrew pitch / (2 x pi x efficiency of ballscreew (about 0,8)). Do bear in mind that the bigger the stepper, the bigger the inductance (the steppert is getting hotter at greater speeds). Conclusion: in DIY setting, if you don't need a lot of speed, you can use 3-4 Nm steppers to move hundreds of kilograms of a gantry. Have fun !
Awesome video.
Now do nema 17s 😂
z axis, what about z up test? the z axis have a spindle weight.
I need to move a slide laterally with a total load of 40 kgs at 10mm/second. The slide is on hiwin linear guides. The calculations are done considering a 12mm ball screw with 4mm lead and the required torque is much below .25 Nm. I am guessing a nema 23 would be sufficient to move that load. Would that be right?
theoretically sure, but practically will be way more, plus inertia. i would recommend 2-3Nm nema 23. or something around this number.
very useful........got it
Steppers or servos for cnc?
You have made same as my plan is(granit) but on hold because money... anyway I'm trying to find information about how many Nm are forces on spindle (both direction) same on linear rails... for example 6mm end mill 4flute and 1m per min @10000rpm ... this is hard to measure. But magnificent build and videos. Oh yes how much was precision granite base??
It is hard to check what is the load on the spindle. i have made a video about breaking mill bits, its my latest one. check it. it could give you some ideas. my standard speed is 1m/min with 11000 rpm, one thing i noticed that you won't break 6mm 4 flute mill, but if you go too deep or too wide you might have different problems.
in my case x axis has 120kg(f) co its not enough to break the mill because it needs double that. but if you go to wide it will get stuffed, or if you go too deep it will break flutes. i guess it will break flutes in both cases. i chipped 10mm carbide mill on the bottom of the flutes and one flute in the middle. perhaps because at some stage i was doing 3m/min. anyway steppers didnt stall. it was the mill bit which fail. if you think about it it makes sense because flutes are very thin at the ends.
now im cutting everything with recipe of 10mm deep, 20-25% side cut. 11000rpm 1m/min. for mills above 6mm.
price of the surface plate was around 600nzd which should be about 400usd
Piotr Fox Wysocki I use € :) and live just above you/ish.. and yes ..your video gave me ruff idea what numbers are there.. Oh yes there is some formula to calculate out.. Thank you again.
I think you should check it at various speed of stepper motor..and that way you have a better approximation of power of machine
Exactly. Stepper motors are approximately constant power machines. Power = rpm x torque, so as the rpm increase, the torque decrease.
Most stepper motors are sold with published rpm vs torque curves and while not linear, by the time most of them hit 300 rpm, the torque is very low.
For drilling this doesn't matter much, but for cutting it does because the tool has to be able to move quickly under load.
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It turns out that he continues with upgrades over time in future videos and the results are amazing.
hi mate. I like your idea. Can you explain me How you choose right step motor? I try choose however it really hard. My project cnc router dimension are 2000x1300x600 I cannot decide what type step motor need. have a some idea? Fallow plan Y-axis will load about 40-50 kg (or more) . thank you
For a rough idea you can calculate it, just like Fox said - torque of the motor, and the pitch of the screw, will give you a rough idea of the possible force. Go search for calculation of bolt clamping force vs torque, and those equations are the same - just remember that ball screws have less friction.
so im confused. were you happy with that or not? that seems to be in line with the size/type of your machine.
I was just showing how much power steppers have. Cause quite few people where recommending a nema 32 stepper motors for lighter machines for no reason. Anyway it was a visual demonstration how steppers behave once they are installed.
microstep have effect quality cutting model ? such angle streaky unattractive surface ?
It's not so visible on a straight line but you will see faceted edges on round corners, circles or cuts on an angle. More mictosteps cleaner the cut.
Would a nema 23 be enough to pull plastic in a packaging machine ?
impossible question to answer without any details. but i would say yes. if stepper by it self will be not strong enough use gearbox. i don't think this answer is terribly useful :)
Why do you have such a large motor on the Z? I would think that the Z would do the least heavy work of all axes
Did I just watch your z axis ball screw move upward twice? It looked like the end stop on the screw failed.
It was the top plate bending when stepper motor lost stepp it springed back. No worries I have changed the design. And by accident I crashed my new z axis into the vise with 750kg of force. New design worked just fine. But since then I have lowered torque to 80kg. (Servos)
@@PiotrFoxWysocki ouch. Bet that stung
Thanks for uploading such an interesting experiment!
I have two questions. The first is pretty dumb maybe. I saw that you're driving the axis directly. So, if I have a 1:100 gear let's say, and a rock solid setup, can I pull ~1 ton with this thing?
Other question: can you please share some details from the power supply and controller? Thank you!
well... :) its way trickier than this :) i can pull 1 ton with X axis just as it is. to pull or push you don't need as much force. to lift you need much more. so this what i showed on this video was lifting power or compressing force.
with gearboxes if you have 1kg lift and you add 1:100 gearbox you should have almost 100kg lift.
power supply which i have is 48v and controller is gecko540 but i will be changing it in the future,
@@PiotrFoxWysocki Thank you very much for your detailed answer. Sorry for the poor choice of my words. I would like to lift then. :) So let's say, I would like to attach a piece of material between the moving nut and a fixed end, like a tensile testing machine. I saw that you reached more than 200 kg on the z-axis. If I would use gears, let's say 1:10 with your z-motor, and no friction, bending...etc (totally ideal case) would be there, would that mean that I could lift ~2000 kg? Thank you!
Yes, that would be correct.
@ That would alter and be altered by speed and acceleration. Yes, the force developed by the 1÷10 ratio gearbox would be 10 times bigger, but the speed of lifting would be 10 times slower. If you want some acceleration too, things change a lot.
@@mihailfelixdumitresc Thanks for the answer. In the past year (since I made that comment). I learned a lot about stepper motors, gears and stuff, so now I know all these things. Actually, the speed was not important for me. I was just amazed by the strength of a stepper. I made a setup, which is based on a small NEMA17, a planetary gear and a worm gear, and now I can exert more than 500 kg pulling force. On paper, multiple time of it, but my load cell can only go up to 500 kg. Have a great day!
made me physically ill to watch the fail, (lost steps are death to a 16hr job.) while 100kg is huge, i wonder the force of high-speed change of direction, that gantry looks stout.
can you share your x,z configuration of screw nut/carriage plates? you have a great low profile design.
gantry weight is around 60kg. so i have 150 kg to spare. and my top speed is 3000mm/min. top speed for stepper with no load was around 5000 mm/min. so i backed down to something reliable. i will share my fusion 360 files for the X-Z configuration in my next video about machine.
you guys make me do another video about steppers and speed/accelerations :) its good to have clear topic for the video :)
That comment about sharing the Fusion360 files is pretty exciting :-) ALso, are your linear rails the really cheap knockoffs from China, or genuine Hiwin? I remember you were not totally impressed with them when you got them. I presume however that they are still much superior to supported circular rails?
my rails are cheap knockoffs... dont ever buy this s#$%!. i had circular and they where much worse. about fusion i will just share the z axis, because rest its totally depended on the circumstances of your design.
Good fun!!!... bloody scary tho'! :o)
Torque stepper nema 23 🤔🤔🤔???
What stepper for lathe for wood?
Not sure on the size of your cnc. But most likely some mid torque nema 24 should be enough. Closed loop would be great
This was the same machine doing 10mm depth with 6mm step over??
yes it is. and it was 10mm deep with 8mm step over :) but since this video i have changed the spindle
@@PiotrFoxWysocki I was thinking I would have to buy 11Nm steppers for that kind of performance! It's good to know I don't need that anymore and I can save some money
i wasn't expecting that result.
216kg is 7619.18oz on Z which is way higher than the steppers oz rating. around 63 times higher.
its because you are converting lots of turns of the stepper in to small linear movement. so one turn to move it 5mm.
Beside OZ are calculated one inch from the center of the shaft.
so if you attach a 2inch/5cm pulley to the shaft this would result 1inch/25mm from the center of the shaft. When you attach rope to this pulley you should be able to lift the amount of Oz the stepper is rated to.
So 16mm ball screw is 8mm from the center of the shaft vs 25mm. So you "kinda" gain some extra power.
I only can have hope this explanation makes sense :)
It's a leverage situation. The motor applies force on its rotor at the (internal to the motor) radius of the rotor. The ballscrew outputs force at its radius.
Suppose the rotor has a 24mm radius. If the ballscrew is 8mm radius, that is a 3 to 1 lever; it increases the force at the radius of the ballscrew to 3 times the force at the radius of the rotor, and the speed at the radius of the ballscrew is 1/3 of the speed at the radius of the rotor.
To simplify comparing motors, the oz-in rating uses a standard 1" radius.
The torque is multiplied by the thread.
@@1pcfred agreed; a finer thread will trade off speed for increased force (like putting a car in a lower gear).
@@scottwillis5434 a thread is a lever wrapped up. Which is like a wheel stretched out. Archimedes was brilliant to conceive of it. There's only a couple basic mechanical principals so you have to be very creative to come up with something unique using any of it.
Hey gr8 test man, actually u did put u r machine at risk to help increase our knowledge. Will you plz let know how much is your machines x,y,z length. The dimensions of the rail guide and the ball screww dia and the type plz. Also the length & dia of guide and screw length on all axis....Plz plz
i will be replacing all of them because they are terrible. not even worth mentioning.
@@PiotrFoxWysocki hey thanks for u r reply... Will u plz help me with u r email, I want to discuss few things about my machine that m about to get started to build
Are you in full step? Or microstepping?
tricky question :) gecko driver has only one mode. 10 microsteps.
Piotr Fox Wysocki really? Why? :-)
Piotr Fox Wysocki. I hoped that you can show us differences between full step and microstepping. Another time :-)
There is no difference in maximum thrust between full and microstep. Thrust for a programmed position is a different story, but you have to measure position to see the results.
Have you tried it with your new setup?
beside the new spindle i haven't changed much.
@@PiotrFoxWysocki that's my fault, I am watching so many builds I thought you had upgraded to servos. I hope you don't mind but I am going to build a CNC based on your concept/design, I always loved the idea of a granite cnc bed it hadn't occurred to me to do it the way you did.
Keep up the good work your machine and upgrades are very inspiring.
@@andrewculverhouse8914 no problem. And don't worry about copping my ideas. I started documenting my build because no one did it before and there was nothing on TH-cam. I thought it was interesting project to share and for others to use granite surface plate idea in their own projects. So go nuts and have fun ;)
Have you ever considered making it 4th axis capable? I was looking at yours and thinking that I'd increased the height of the sides then build a spindle into each side (I actually have a spare Colchester lath spindle I could break down and use for this) put it on the one side on a worm drive with a stepper or servo. The advantage is the spindle I have has a through hole so if I set the other side up almost the same with another spindle or some sort of carrier I will end up with 20mm or 4/5ths of an inch diameter holding at any length as it can go through the machine and out of both sides. And if I wanted to I could bore this out on my lathe to about 40mm without affecting the strength of the spindle.
I have bought a nema 23 stepper motor kit from ebay and i can't even move my machine. 35v, 425oz./inch. Do you have any idea what is going on. ? Thank you.
This question is as generic as it is possible. I have to ask ;) did you take those steppers out of the box?? ;) I guess you have leadshine stepper drivers. I'm guessing maybe you haven't connected the ground to step and direction inputs. It takes 5v input signal and ground
@@PiotrFoxWysocki the system is working but the torgue is very low. The settings on the controllers are on max amps but also i can stop them with my hand. Is it good idea ti increase voltage from 35 to 45-50, the controllers can aford it.
@@Nikos_Katakis wow. something is seriously wrong. increasing voltage won't do a thing. more volts - more speed, more amps - more power. i have to ask, what is your power supply? Amp wise? another question would be if you are sure you connected stepper leads right? if its noisy and spins erratically it means its wrong.
@@PiotrFoxWysocki the power supply is 35v 10amps and this is for 2 motors and one more for other 2. Plenty of amps... :p a belive that the conections are good because out of the machine the motors work well with out bad noise.
@@Nikos_Katakis i presume you haven't plug step in to direction and vice versa? only one thing left are the drivers. are you sure they are not set to some minimal Amps? in some you have to use resistor and maybe resistor is 10x or 100x too big or small.
Would never use stepper motors no matter how cheap after I built my CNC using Clear Path servos.
I do very heavy rapid cutting on them and even set to only about %30 of full torque I have never had an issue with them.
Also they are no more complicated to hook up than a stepper motor
I don't know why, but I'm not able to conceive this. How can a motor rated 4N-m~= 40kg-cm produce almost 200Kg of force. From your setup, I assume the distance between the hook and the motor(Z-axis) is about say 5cm. So, by the torque formula(T=F*R*Sin(¢°), here-¢°=90°) force should be 40kg-cm/5cm = 8kg.. Technically, force should be less than 40kg for all distances>1cm..
Please help me out.. This concept has always bounced over my head..
hmm.... looks like your calculation is incredibly precise. you just missed one 0 at the end of 20kg :) I prefer to test stuff instead spending time calculating something where i could miss something or put dot in the wrong place. as i mentioned before i have lots of experience wits steppers and i have a lot of all sizes, so it turns out that is too small i get bigger one.
566 oz.in means that if you attach a pulley which radius is equal to 1 inch and you attach string to it, you should be able to lift 566oz or 16.0458kg. I never bothered to find a right formula to calculate it. i guess to make you mathematical problem even more painful i want to add that i haven't been running those steppers at full power, Amp wise :)
@@PiotrFoxWysocki Oh great! Owing to the budget constraints, I tend to rely excessively on calculations beforehand investing into anything! Certainly, it's very time consuming, tedious and prone to errors but saves me some bucks to balance the equation. Anyways, loved your video! Amazing!!
👍👍
There are at least two reduction ratios:
1. (If used) any pulley ratio (minus mechanical losses).
2. Radius of the ballscrew: if stepper torque is (for example) 325 ounce-inch, a 0.5" diameter ballscrew with a 0.25" radius would give a 4:1 reduction (1" measurement radius / 0.25" radius) and 4X the ounces (325 oz-in / 0.25in = 1300 ounces).
A 0.5" ballscrew might be a bit undersized here; chosen to simplify the calculations.
3. Thread pitch of the ball screw. A smaller pitch will give lower speed and higher force. From the Wikipedia "Ball Screw" article:
F = (2 π v T) / l, where:
F is force,
v (correct Greek character is unavailable) is the ball screw efficiency: 20..25% (0.2 .. 0.25) for Acme thread, 90% (0.9) typical for a ballscrew,
T is torque applied,
l is ball screw lead (distance the thread advances per revolution)
Picking an arbitrary 0.2" pitch and the 1300 oz-in,
F = (2 π 0.9 1300oz-in) / 0.2"
= 36,757 oz = 2,297 pounds force
Which I think we can agree would be more than sufficient for this mill.
A lower overall reduction ratio for higher maximum speed seems preferable.
Suppose the stepper + drive is capable of 1000RPM:
1000 rev/min / 60 sec/min * 0.2"/rev = 3.33 inch/sec, which seems rather slow; a 33" move would take 20 seconds.
Looking at rack and pinion:
For an example 25-tooth helical gear, pitch diameter 39.79mm, direct drive:
F = 2 T / PD
(Using 2 / Pitch Diameter as 1 / radius)
F = 2 (325oz-in = 2.295Nm) / 0.03979m
= 115.2N (25.8 pounds force)
Which seems insufficient, requiring gearing or a pulley setup, or bigger steppers.
Designing for 100kg force (per Piotr's video around 3:00), 220lbf, an 8.5:1 ratio.
Fuc.. 8o A ja dzis kupilem online nema34 13Nm na Y i 8.5Nm na X hehe pierwotnie mialy byc nema24 ale stwierdzilem ze brama jezdna wazac jakies 50kg to za duzo na nema 24 a tu niespodzianka 216.5kg no coz zapas mocy tylko sie przyda a nie zaszkodzi
hmmm... mozesz miec problem jak cos zle ustawisz i maszyna sie samo zniszczy :) bo stepper bedzie sie krecil dopoki nie zacznie gubic krokow. opcje, ablo ukrecisz zlaczke, albo zdeformuje ball screw, albo rozwali ci rame. tak czy inaczej wiecej zniszczen niz pozytku
1Nm nearly 22 kg
2:00 it's on a worm screw adding power
Imagine getting pinched
i prefer not to :)
man please don't do this kind of "tests" on your machine.
steppers has enough power so machine can easily damage itself or loose alignment of some parts. especially powerful steppers/servos which you probably will use in future.
i won't do this again. but i had to do this for science and grater good :)
I'll admit, I was definitely concerned about your gantry. Thanks for the experiment "... for the greater good". ;)
50 kg