Toolpost Grinder Part 24: First Test Grind
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- เผยแพร่เมื่อ 30 ก.ย. 2024
- The day has arrived! We finally test the toolpost grinder on a poor, unsuspecting piece of mild steel. After some experimentation, it turns out the best recipe is just a dressed wheel and soluble oil coolant. We also try some other common tricks, like beeswax and polishing compound on the wheel.
Drawings for this project are available here: clough42.com/20...
If you haven't seen the previous videos, a playlist with all of the parts of this project is here: • Making a Toolpost Grinder
If you're following along, here are some of the tools and other stuff used in this video:
*This site contains affiliate links for which I may be compensated
Noga MC1700 Mini-Cool Kit (Amazon*): amzn.to/2qgemiM
CRC SL2512 Soluble Oil (Amazon*): amzn.to/2qhWswk
Pig Mat Universal Oil Absorbent Roll (Amazon*): amzn.to/2H7Rb4H
Green Polishing Compund (Amazon*): amzn.to/2JxrRU8
GX16-4 Aviation Plug Connectors (Amazon*): amzn.to/2JrNhCh
Shars CCMT0602 RH turning tool holder (eBay*): goo.gl/Q1Jsdp
Kyocera CCMT060204-HQ Cermet Inserts (eBay*): goo.gl/pDhFAs
This could be my eyes....but I am seeing your lathe running 'into' the rotation of the grinding wheel.
This means you have to subtract the 150 rpm the lathe does from the rpm the wheel does.
The lathe should be running in reverse and faster. So you can add the surface speeds of both!
Your finish will be a lot finer and you will develop less heat.
Is the grinder running at max rpm? It sounds like it isn't.
On a different note.... I am glad you have gotten enough beeswax for all of us LOL! (a tiny bit of beeswax is ok...'less is more')
loading up the wheel with polishing compound stops it from cutting.... not a great idea. (barely a spark after you put the green goop on)
That said.... great design for a toolpost grinder!
Paddy
I was wandering if I was wrong about the rotation of the two parts. I was doing something like this in the past and was finding that if running "into" the rotation of each part that the grinding wheel was being ruined and the part was not better for it. You would be basically "driving" the parts together with the force that the lathe could cause! Yes it looks shinier, looks like the water is helping.
@@rogero9633 bb7
Yes, it seems intuitive to me to have the part rotating up against the wheel rather than with it. The way shown seems to be the equivalent of "climb milling", kind of grabby in a way.
I was thinking the same thing
If the lathe is running at normal rotation, counterclockwise, the grinding wheel should run in a clockwise direction from the end of the wheel. In other words, against the rotation of the part. Tool post grinders usually run rapidly, around 6,000 for larger wheels to as high as 10,000 for smaller ones. The higher the speed, the better, up to the rating of the wheel. Internal grinding wheels can run at 15,000 rpm. Then you add the rotation of the lathe to that and you get a very high speed. For steel, never put any crap in the wheel or the part, just water soluble oil as you’re grinding. That will keep the cut clean and cooler.
I spent 2 days binge watching the whole build series. Great job and the first results seem to show a lot of promise. You should feel proud of the whole build in my opinion.
Thanks. It was a long build, but I'm pretty happy with how it turned out.
Hi James, I'm not a grinding expert by any means, but I think you're going to want to have a narrow band of the wheel touching the part rather than the whole face. You only cut with the first narrow band that touches anyway, the remaining contact just builds up heat in the part. You can see that for yourself on the bench grinder. If you use the corner of the wheel by sweeping across it, you can grind for an indefinite period without the tool bit (or whatever) getting too hot to hold. If you plunge the whole thing into the face, it gets hot quickly, and doesn't really remove a proportionately larger amount of material. Anyway, I'm not sure if canting the wheel at a very slight angle or relieving the better part of the edge is the better approach, but that would be the idea. Solid Rock Machine Shop is a TH-cam channel by a very experienced grinding hand. I learned a lot from him and he's responsive to questions: th-cam.com/channels/KPqKYF73sJbFUSzo5dQxtQ.htmlvideos Congratulations on finishing the build! :)
Thanks for the tips. I learned a lot doing this, and that's one of the things I picked up. Because my diamond was going away while I was dressing, the right side of the wheel ended up slightly larger than the left. This meant that it was constantly engaged over the entire face and it left a small taper (a couple of tenths) on the last half-inch of the grind. Had the dress been cylindrical, it would have just been cutting on the leading edge, working across the face of the wheel as it wore. I have a new diamond now, and I'll be dressing more quickly, finishing left-to-right to focus the wheel contact. I suspect that will work better.
Agreed. I think the width of the wheel should correspond with the power of the grinding spindle. (and the rigidity of the setup)
@@Clough42 A Cold Gun would help keep the heat off the part. Plus run the part in reverse will help with the finish.
I don't recommend using coolant on a Manuel Machine.
Old Guy Machinist
As for getting the diamond to stay intact, you have to cool it down. Point a mister or flood coolant against it or the epoxy/resin/watever will melt away. It also prolongs the life of the diamond itself.
Your wheel should be running in the opposite direction of your part. You can't run them in the same direction. Make another video going in an opposite rotational direction. Also, change to a different wheel. One last thing, the material you are grinding is not that great to grind so that also comes into play.
You are climb grinding. You’ll get better results if you reverse your lathe spindle and conventional grind.
I always thought the work had to spin opposite the grinding wheel, maybe it doesn't matter but as mentioned your losing grinding wheel speed that way, also the work will be pulled round by the grinder.
Is it not?
It does matter. The grinding wheel should turn into the part rotation, not with it.
@@melgross I thought so, thanks for clarification
Bees wax and jewellers rouge are normally only applicable to grinding soft metals like aluminium and brass. They keep the stone from loading up with metal.
Part of your problem here was also the grit of your stone. 45 grit is a medium to course grade stone fro surface grinding. 70 to 180 grits are preferred for glassy reflective surfaces. Normally aluminium oxide is the most common abrasive used but recently there is a new player on the market which is ceramic aluminium oxide which is ideal for surface grinding. Ceramic aluminium oxide is very hard and strong and has the ability to fracture at a sub micron level to continually expose fresh cutting points for smoother more precise surfaces.
Lastly, your technique. Surface grinding in a lathe requires cooling if you want a good job. Surface grinding a flat surface on a surface grinder is normally larger parts and your surface area to dissipate heat is larger because you are only grinding one of four or more surfaces (the other surfaces act to remove heat into the air) thereby giving less distortion. However, even on a surface grinder it is generally recognized that coolant will given you a better finish. In a lathe, coolant is virtually mandatory since you are grinding not just one out of four sides but all around and the heat cannot dissipate as rapidly. ALWAYS REMEMBER that heat always travels to cold. When you grind without coolant on a lathe, the heat is travelling to the core of your part causing expansion and distortion. When using a coolant, the coolant is normally cooler than your part and the heat draws into the cooler coolant and away instead of your part.
Your grind went south on your very first pass because you tried to take too much material. Place your stone over the material and use the full face of the stone and not just the leading edge. The slowly and carefully feed your stone into the surface. As soon as you hear the stone come into contact with the material STOP FEEDING. Make a pass and let it linger for a second or two at the end of your pass before pulling off. Repeat until you have the finish and measurements you are looking for. The reason you linger for a moment at the end is to allow the stone to finish the grind. When you are travelling along the surface you are exposing your material to the complete face of your stone gradually as it passes over the surface. If you don't have a runoff area at the end of your grind, you must ling for a second to get a full grind. If you don't you will gradually grind a taper.
Another way is to grind down to your finish end, linger for a second or two, and then grind back to the start end. This will give an even better surface than pulling off. Think about it. When you run a surface grinder, your piece is run back and forth over and over while gradually feeding your way across the entire surface. You never lift the wheel so you never lose your depth setting. When you complete your cycle over the surface, you drop your wheel a few tenths and grind back to the far or starting side unless you are satisfied with the grind you have. When you pull off like you did in the lathe, you lose your setting and have to start all over again on the next pass. Your chances of repeat-ability are greatly reduced. If you grind both ways this factor is removed from the equation. SLOW AND SURE is the best way to surface grind. It is not a process that can be rushed.
Thanks for the info. That's very helpful.
@@Clough42 Scooter tramp is in my estimation exactly correct with his advice. The thing that struck me was the sound from the setup whist grinding even the smallest of cuts which made me certain something was loose. I'm sure it wasn't as you are very careful but the point is the set up needs to be much more rigid as you can't do a great deal about the lathe other than getting a bigger( preferably industrial) one.A guy with your ability really should consider getting industrial equipment- it make s a world of difference. Thanks for your videos- All very interesting and well thought out.
Hello James,
I am a recently retired (2018) Science teacher, actually I was head of faculty of a large (for Australia) Senior High School. I wish to work in both metal and wood to repair/ build old clocks and work on many other projects. (I have 3 lathes and 1 Mill) However as someone new to metal lathes and mills I have found your detailed demonstrations of using your lathe most helpful. I understand many of the principles but to see you go through using the four jaw chuck then exactly how to centre (I am Australian therefore the English spelling) work pieces with copper shims was most illuminating. I appreciate your clear and thorough explanations. Thank you for making your videos I have subscribed and will continue to watch and learn.
You're welcome.
Seems like you are loosing your SFPM by having the work and wheel running the same rotation. Think about a wheel and work of the same diameter and same RPM, in my world that equals No SFPM. But then I am getting a grinder this month and I will get to experiment with such. Keep on trucking and congratulations on your work!
This is true in general, but in this case the difference is very small. The wheel is 4", spinning at 7000 RPM, for a SFM of 7330. The part is 1", turning at 150 RPM, for a SFM of about 39. So in this case, the difference is 7291 vs 7369 SFM. This lathe doesn't have tumbler gears, so if I wanted to power-feed toward the headstock, I didn't really get to choose the direction for the part.
@@Clough42 The way the grind wheel cuts changes, where I work we have extremely large cylindrical grinders. The work piece rotates very slow but they are always climbing. Its not just about surface speed. Obviously you dont want to run the wheel the opposite way though. Other comments about running off the ground area at both ends are good but not always possible. So many shafts have shoulders that prevent this. Excellent work.
Looks like coolant is the ticket. Have you tried running the lathe in reverse?
Hi James,
It was nice to see the grinder in action. If you start your cut in the relief area and cut toward the tailstock you can eliminate the taper due to wheel break down. What hardness is the wheels bonding? Also, if you have an open structure wheel it will cut a lot cooler.
Steve
Thanks for the tips. This is the first grinding I've done. The wheel I'm using is just a snagging wheel from McMaster (44611A111). The specs are sparse, but it's a vitrified clay brown Aluminum Oxide wheel in 46 grit. I've been having a little trouble finding wheels that can handle the spindle speed without spending $100 for a Du-More. Is there someplace else I should be shopping?
If the point on the diamond dresser is to sharp they can break off if dressing a coarse wheel . What grade of wheel are you using ? I see you have a few comments about the rotation , the TPG in a lathe is a completley different thing from cylindrical grinding & works best i find with slow rotation & fine feed . The work rotation you have used slows down the surface speed & in my experience with my TPG gives a better finish . Nice job , Cheers .
James, I subscribed to you recently after stumbling on to one of your videos. I love the work you do. The toolpost grinder build is fantastic. Thank you.
turn the workpiece in opposite direction to the spindle rotation ..??---so that they aggressively ENGAGE ratrher than escape contact....??!!
Your lathe should be in reverse it will cut better
Is it just me, or should you not run the lathe in reverse so that it’s bringing the mild steel up into the downwards spinning grinding wheel? 🤷♂️
If you run it in forwards then the steel is running down in the same direction the grinding wheel is turning.
Your work is rotating the wrong way, the work must rotate in the opposite direction to the Wheel, adding junk to the wheel is a bad idea you should never do this, all this will do is load up the wheel, the wheel dressing diamond was bad before you started, you could hear it when it was cutting, listen to the sound in the video the diamond was rattling around in the holder, you need to dress with a coarse pass / cut also, .0001" or even .001" on a wheel like that is not going to give you a dressed wheel suitable to grind the Mild steel, so may have to rethink the Diamond mounting as it does not look ridgid enough, for wheel dressing, the wheel being used is questionable also
Really nice work! My only tool post grinder experience is ID grinding but I’ve always had the wheel and part running in opposite directions.
It’s possible that I missed this in a previous video but I would be interested in seeing the electronics in a bit of detail. Thanks for making this and allowing us all to follow along.
Thanks! I'll eventually put the electronics in a box, and I can put together a video on that then. It's pretty simple, though--just a power supply and an eBay speed controller.
Did you spin the work opposite the wheel direction? You should try it.
У тебя всё хорошо ! Только шпиндель нужно включить в обратную сторону!!!😊
Am urmarit aproape toate episoadele ,lucrezi foarte profesionist si corect. Toate piesele sint la nivel "de firma " .Pentru ultimul episod , viteza pietrei poate fi mai mare dar piesa de executat trebuia sa se invirta in sens invers.Lucrare de nota maxima.
I'm not sure but i think it's better if your spindle direction is clockwise !
Yes, technically that's probably better, though it probably doesn't make much difference at this surface speed. Since my lathe has no tumbler gears, I had no choice if I wanted to feed from right-to-left.
I can hear the lathe head bearings and the cross slide is not ridged enough - its a lathe remember !!!
Try turning the lathe in reverse and slowing thr Rpm down.
Nice. Is it possible you can do ID grinding with it?
As for the wheel, you might want something like an 60-80 grit wheel with quite soft hardness. Don't let the grit fool you, as diamond dressing will 'dull' the wheel and it will produce very fine surface. For extra fine finishes I would go for lapping instead of finer wheels, but 'it depends' on what you want to do and how and for how long.
Amazing work. One day I need to build one of these.
Did you measure the diameter to check for taper?
What grit & manufacture of the grinding wheel
be nice if you had the els from the future.. the grind looks perfect..the most fun is to grind really low grade chinesium and see how smooth you can get it.
Thanks so much for sharing your experience and your learning with us. Truly a pleasure it is to watch any of your videos. The shop and capabilities you have built up are admirable to say the least. Well done Sir!
I frequently grind small cylinders on a surface grinder with various "whirly-gigs" or "spin-dexers". Some keys to precision include:
-Temperature stability through the whole system (workpiece, grindwheel, bearings, machine frame, everything). Toolmakers far more skill than I have might turn their spindles on hours before chasing supreme results. Most critically the wheel grows with heat input; affecting precision, cutting-load, and heat input itself. larger wheels come with greater consequences.
-The workpiece axis and grindwheel axis need not be parallel. Parallelism of the wheel face is imparted by the dressing operation. A higher skew angle will bring a surface speed gradient which can interrupt harmonic vibrations and improve finish. Also the need to dress a relief onto the wheel face is reduced when one has to face-grind a cylindrical part.
-Do not turn off the spindle immediately after finishing a grind to allow it to dry. This is particularly true if flood cooling is used. Fluid which might have permeated the porous stone and is allowed to remain there can settle over time. This can affect the balance of the wheel at the next startup.
James,
Thank you. I have watched the whole build with great interest. As a beginner I have learned a lot. I do not think I am ready to have a go at one of these yet, but the fact that you showed the whole process: set-ups, measuring, tool selection and speeds in particular is something many of the other expert video makers tend to assume we all know and so skip over. I shall watch all your offering from now on. Thanks again.
Mitch
Hi, just finished to see the last episode of this great project, interresting subject, excelente work, congratulaciones, keep It Up ! Thank you for sharring with us.
don't know if it was the dressing of the wheel, it always wears off more at the front, try to go past the end of the grind next time and come back with another tenth of depth so the back becomes the front on the return pass - you should aim to have the grinding wheel past the end of the part on every pass and also grind both directions. That happens even with narrow wheels and dressing between passes might be required at the end to make sure it grinds on it's entire width and the part is consistent in diameter.
Yeah, I think this would make it better. I didn't take the time to cut a large enough relief for the wheel to run off the chuck end of the grind, and it is a little larger right at the root.
. . . or, at least plunge in near the chuck ad travel OUTWARDS, the trailing end oof the wheel will result in even diameter part, the leading edge of the wheel wears first.
Ciao James grande progetto, è un pò che sto pensando di costruirne uno, ora che ho visto il tuo progetto inizierò sicuramente. Grazie per i tuoi video bellissimi e anche se non capisco la tua lingua, li seguo molto volentieri. Ciao
Generally a ground finish is for accuracy. The finish is a nice residual effect, but you never put a micrometer to see the size or parallelism. Honestly, I could give a part that wonderful finish with some sand paper and finishing off with Scotch-Brite.
Your lathe head bearings are not good enough
If you want to hit consistent diameter from end to end, start your cut at the groove (left) end. That way it will be wearing out on the right hand side and the part of the wheel that started in the groove will be non-wearing surface, thus providing the 'sizing' for the grind. Otherwise you might end up with a slight taper up to the groove and/or loose tolerance over the whole length or have to redress and grind again.
And I'm not sure what the wheel you have is, but it sounds a grade or two too hard or the wheel is too fine grit. Typical wheel we use on a cylindrical grinder (which you basically now have) is 46 grit and it leaves a nice smooth surface.
Kick that grinder offf a couple degrees so ya cuttin with the edge not the whole face of the wheel. Less heat less strain on ya grinder. Great finish too. Cool videos by the way
would like to see a follow up with a good dress
Many thanks for the drawings!
Dang now I need a 3D printer to go along with my CNC. Nice job on the grinder and the results show it. Another successful project! Great video!
Thank you.
Congratulations James. That was a fantastic result! I wonder if the material holding the diamond was weakened when you drilled behind it?
That's definitely a possibility, and it was one of my major concerns doing it that way. Looking into the hole, I didn't think I'd gone all the way through the steel, but it's hard to tell. I ordered a new mounted diamond dresser from McMaster-Carr, and I think I'll come up with a way to mount it without drilling it out this time.
Just finished this epic journey. Well done!
Yyou need to run the laithe in reverse and at about 25rpm.
This lathe did not have a feed reverse, nor the ability to run that slow.
If you mark the work with a felt tip pen, when the wheel starts to remove it you know you are within a nats of the work.
Good tip. Thanks!
Ah OMG. The tool post grinder could be driven from the ELS as per my post on your ELS project. You've been a busy man in the design space James
Well I watched the whole series. Very disapointed that you didn't check the finished result for being parallel and round, particularly as you took great care with measuring all the way through the build.
Lots of ektsperts here. You can turn the work in any direction you want. Clockwise or counter clockwise. While the the norm would be to run the lathe reverse, it also really depends on how your specific situation works best for you. You might get better results doing it just the way you are. I wouldnt be running the lathe up to higher speeds. Grinding is slow and the grinder needs time to move over the piece its grinding. Going in the same direction - grinder/workpiece will not cause the 2 to feed into each other. This is totally absurd.
Cool, no coolant while dressing will wear that diamond quicker I know it's testing time. Idk what type of wheel that is though. At work we will have a feed back and forth and feed towards the diamond until we touch, turn on coolant, then depending on roughing or finishing 1-4thou in to dress
Are you shooting for a certain finish or just Shiny ? You need to mic the part and check for straightness , on a cylindrical grinder I would be feeding in on both ends of the part to keep it straight, not looking for a shiny part but one that is straight. Do not go off the part on either end, do a fast dress with a sharp diamond.
Those cemented/sintered diamond dressers are cheap, and useless in the long run. Spending the big bucks for a "solitaire" is actually worth it.
Undiluted coolant. The brown liquid moderately used. Excellent for Aluminum. Will sling a little but not a problem. Excellent for surface grinders. Good for steels also. Wheel BALANCE is imperative. Go with AlO3 white or pink for steel 60-36x. Try 60x. I'm sure you know...trying to help. You sure are helping/helped me.
Much appreciated. -Tom
Hi, James. Went back in time to check this out after it popped up on the sidebar while watch Mr. Crispin's latest video. As always a great video with good info (I'm not brave enough to make a grinder for my 7x16, but am always looking for techniques).
Also, continuing our conversation on weight/shape loss, I had forgotten how former you looked. I can't thank you enough for your inspiration to finally do something myself. I passed another milestone recently, getting a new drivers' license (kept the old on to remind me): unlike TSA & CIS, traffic/safety officers don't use facial recognition so I figured I better be safe (also needed an up-to-date photo so I could get served in airports and similar locations where they card everyone).
All my best, Charlie
*_The vibrations going through the cross slide and compound slid can affect things too including moving the feed into the work. I lock my gibs before grinding and it has helped a lot and stopped any vibrational feeding._*
Your rotating the work in the wrong direction, rotate the lathe backwards max cut two tenths of a thou
Thanks James a very professional build as usual......from New Zealand. Beagles.
I think you need to run the lathe in reverse so your wheel and work are turning in the same direction..
Can you tell me which type of sharpening stone you are using correctly, is it a soft or hard stone, and can you give me the correct type and number, thank you in advance.
James I’m a subscriber to your channel. Big thumbs up to your videos. You are a fellow engineer, as I am also I have the sam equipment you do and your are a master, Sir. My hat is off to you you do so much with what you have. I can’t wait to see a project with you motor and spindle on your G0704 CNC. The grinder is a work of are really, and I enjoyed them all.
Absolutely a work of art. Yes, I had to binge watch also...😊. The electrical guard is a "touch of class".
23:31 the sparks good really good on that pass,,great DYI grinder. I have a Themac, but she doesn't get a lot of use, but a tool post grind is a must have iin the shop,,Bear
Time for a update on this project. New diamond dresser and electronics enclosure
When I was an apprentice we had to machine the OD of a Screw Pump that had its auger hard faced, we retro fitted a pedestal grinder to do the job. Then a new linisher was bought for the workshop it was instantly fitted into the tool post and performed a way better job than the grinder. The grinder was never used again.
I wonder if replace toolpost electrical motor by air motor/ Air motors have less weight /. Do you think it will make sense to do that?
I made a mdf wheel for compounds to get a mirror finish. great grinder build but a waste of time with bad dress. thanks
What is the diamond metal piece used for?? to even out the surfaces? or what
I think the wheel and the part should be rotating in opposite directions.
An excellent series, and a very fine product. Congratulations.
blaa blaa blaa
Aren't the part and the tool supposed to spin in opposite directions?
Yeah, they use flood coolant because it works the best :)
I own a machine shop we do tons of cylindrical grinding.
Have you ever noticed how when you see parts being ground the part is fairly flooded in coolant? I can tell you that's for good reason. The part must be kept cool when grinding or it will swell from heat as you soon found.
More coolant sir, more the better.
Mist is what I have, so it's what I used.
I know its an old vid. But isnt the lathe supposed to go in reverse, opposite direction of the grinder? Seem to me like the rotation speed are canceling eachother out to a certain degree..
The speed difference is so great that I makes essentially zero difference. At the time, I had no ability to reverse the feed on this lathe, so I couldn't run the spindle the other direction and still feed right-to left anyway.
can u put a gauge to see the precision of the resulting piece? How accurate can u be?
James, you are one of the very best instructive youtubers.
I have only one criticism... you should have put the link to these drawings in the first video, so I didn't have to watch 23 previous videos in the play list before getting to the one with the drawings, which would have been great to have had while watching the earlier videos ;)
Yeah, I should go back and do that. They weren't done when I made the first video. :)
Aren't you supposed to reverse the direction on one of those things that are spinning?
...Just something I heard. I've also heard that water alone is fine to use.
Honestly though, I'm a new machinist. I went to school for manual & CNC machining and have taken such an interest to it I've probably watched around 2,000 hours of machining videos on TH-cam and kept going to school till they essentially told me to get lost because they've got people to teach that are still paying. lol
Wish I would have figured out how much I love it 20 years ago. Then again, I wouldn't be a jack of all trades. We get a bad rap because nobody ever finishes that saying.
I think running the spindle in the opposite direction would be preferred, but the surface speed is so low that it probably doesn't make much difference. Since my lathe has no tumbler gears, I had no choice if I wanted to feed from right-to-left.
You have to balance the girding stone in a grinding stone balancing fixture, if not then you will get vibrations and surface inaccuracies. Normal pass depth is 0,02 of a millilitre. And it sounds like the stone is too hard. No the stone is too hard and it needs balancing. Grind a piece of harden steel RC 60 with that stone, will be a polishing process and not a grinding one. Grinding machine have increment on 0,02 millimetres and can be set to take a max depth of 0.05 when using grinding stones, using diamonds are another matter. Metal part are usually roughed to 0,2 millimetres prior to grinding. The surface is just a little too bright, a dull grey would have been better but, Well done!! A good tool and a good video.
Agreed: this particular stone is indeed too hard.
WOW. Watched the whole series. Lots of work on both the grinder and the video editing. Very nice job sir. So this was a 8 month project judging from 9/17-5/18?
Probably something like that. I worked on some other stuff during that time. Like video editing. :)
The lathe should be running in reverse.
enjoyed the video, wld be even better viewing but for overzooming to the point of your camera being unable to focus. a somewhat larger frame would also convey more information..
Thanks for the feedback. I generally try to provide a mix of different angles and zoom levels and choose the shots to best illustrate what I'm trying to show. Sometimes you get to see a bad shot because the other angles I had were even worse.
The tight shots in this video were shot with large-sensor camera and a long lens, resulting in a fairly narrow depth of field. I usually focus manually to avoid hunting. In this case, I chose to focus on the middle of the grind, so you could see the surface finish, and this left the end of the rod out of focus. But since the the ground rod is basically featureless, and the wheel is blurred by motion, you can't really tell.
Sometimes my footage is out of focus because I change the setup and forget to adjust the focus; this time it was out of focus because I made a deliberate choice that didn't end up working out. :)
Would have been nice to see it being assembled after seeing all those parts being made, not always the destination but the journey...
Right 55min video making a tube but no final assembly for 25-30min!
But sir why use tool post grinding and which type of material are not finished by single point cutting tool reason behind use of tool post grinding please give me answer
For better surface finish and for final sizing of hardened materials
@@Clough42 but sir which type of material are not finished by single point cutting tool please give me information means why not use single point cutting tool & when ever use single point cutting are use for finished hard material what can effect u see in tool
The surface finish looks great. How well does it hold a diameter over the part length?
Is it matching your lathe's turning taper? Better? Worse?
It's pretty much cylindrical. It is slightly larger right at the root because the wheel dress wasn't perfect. I have since picked up a new diamond dresser (a more expensive one from McMaster this time) so hopefully that won't be a problem on the next project.
Very nice machine
thanks alot for sharing
How would changing the direction of the material rotation with respect too the grinding stone rotation affect finish and accuracy
Really enjoying the videos and your other youtuber video recommendation's. Thanks for the efforts, very instructive
The wheel surface is moving at 7300ft/min. The part is rotating at 150rpm, so its surface is moving about 39ft/min. Changing the direction would change the relative speed by about 1%.
@@Clough42 I dont know why but watching it , it seems somehow wrong to climb cut the metal with the grinder. have you tried the other direction?
I'm not a machinist, but I did grow up on a dairy farm, work as a cabinet maker for several years and now work as an IBEW electrician for 30 years.
Really enjoying yours and Blondihacks videos. I've picked up so much info on tools and techniques that can apply to so many other projects of mine.
Awesome videos and awesome work!
I have five questions questions now that you are done if i may:
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From an engineering point of view i was allways taught to press in the front bearing and allow the rear bearing to float. I assume, that you floated both bearings to help accommodate expansion of the spindle arbor due to heat. Do you feel differently about floating both bearings now that you have gotten some use out of the grinder?
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Second question: now that you are using coolant to get the best surface finish, do you see less if any heat build up in the spindle, and hence do you think it would be possible to press on the front bearing on if I chose to make a modified copy of your design.
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Three, I thought that grinders were used to true up parts after hardening. Can your design do that? Is that really what they are for?
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Fourth question, does the bellview washer provide enough resistance to movement if one were to cut on the pull stroke?
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Five, what would you have done differently were you to design a new version today.
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Thanks so much for the videos. I learned so very much from them.
Leo
Lots of questions... I chose to float the bearings just to make the construction easier. Pressing them in makes the tolerances more difficult to achive with simple tools. The forces are pretty light, and I haven't seen any ill effects so far for a light duty tool. There is some heat build-up in the spindle, but so far I don't think it's enough to cause any issues. The coolant mostly affects the heat build up in the part. My primary reason for wanting a toolpost grinder was to grind hardened parts to final dimensions. I suspect it'll actually work better for that than for soft steel. But I think that's mostly a matter of wheel selection. For grinding, I don't think there's much axial force, so I think the belleville washer is plenty for this application. If it isn't one could always double them up for more force. I'm not sure I would change much if I were to do it again. I might see if I could find a way to make the spindle more compact so I could use smaller wheels and spin it faster, but it's already about as small as I could make it and use easily-available parts.
@@Clough42 Thank you very much. That all makes sense and I think I'll atempt the project just as you did. As for tight tolerances you seam to do great to me. A friend and I were watching together and he commented that you went to great lengths to achieve tight tolerances to those in the drawing, and asked me what I thought. I commented that at work we are pressed to specify only whats necessary so that the parts can be built as quickly and inexpensively as possible. It also helps prevent the machinists from getting cranky with me for slowing them down with a call for somthing to be unnecessarily tight. But if this your tool, a pride and joy, then why not do you best on all fronts ang get as much practice being tight with your tolerances when you can. Then we both remembered how much fun a home shop can be versus for profit work. Though, I think you could sell lots of those grinders. Every time I see a worn out one on Craigslist for $1k i just shake my head. Thats for the videos. They are great.
Thank you for sharing,
Enjoyed all the parts.
Also liked your lathe gear box,
Maybe you can cover more on how it works.
Don't need to cover any machining,
At least for me.
Thanks.
Dan
Do you mean the change gears for feeds and threading?
Clough42
Yes
Thanks for the suggestion. I do have that video on my list of possible future videos, and I'll add your vote to the list. Change gears are just magic to lots of people, so I do think there would be some value in a video that breaks it down and explains it simply.
Parabens pelo trabalho, ferramentas muito boas.
Thank you!
Mr Clough, many thanks for the informative video series and the drawings. No pressure, but what are we to expect next from you.
Next up: a VFD upgrade for the lathe. I'm getting tired of the belts. I have a few other projects in mind as well. :)
This was painful to watch on so many levels
After almost finishing your ELS project (and starting my own) I got this video in my suggestion list.
Now I have to watch the whole series :-D
I've seen a remark from another viewer about the spindle direction: as far as I learned you do the grinding as "traditional milling" and not climbing - at least that's true for surface grinders.
The spindle of the lathe should be rotating in the opposite direction.
Sparks mean heat is being built up, Robin Renzetti once said that your last cut should seem to not have any effect (no sparks at all).
And my last tip is about wheel wear: always start and end with the wheel away from your part. That way, every part of the wheel (and the part) see an equal grinding stroke. With this demo you start at the right of the part and end on the part - so the most left section is only touched by a thin section of the wheel whereas the rest of the part os touched by the whole wheel.
Ah yes - and the other viewers commenting about accuracy ... a fraction of that reached by professional grinders but it also costs a fraction of the price.
A project well done - I can't wait to binge watch the whole series
I made something really similar to this for engraving on a CNC mill. Even with the very minimal tool pressures of tiny engraving bits it ended up with more than a thou of runout after only a few hours of use, it was very quickly wearing the front bearing. I ended up switching to a Chinese water cooled spindle.
Too deep, wrong rotation, wrong speed. Looks mean nothing if you miss your diameter.That's just in the first 3 min. I have to change channel.
I know this is one of your old videos but I have just found your channel and become a subscriber. I have polished different types of metals threw my life and I have always used the different compounds to heat the metal up . The way I was thought was as it gets hot the molecules split in the metal and that’s when you start getting your more shinny finish but I’ve never seen compounds used on a grinding stone only buffing pads.
Wrong
I have a diamond dresser
我有金刚石修整器
Yiiha! even experimenting with it! haha.
It doesn't really seem to bog down which was my guess for that wheel and that reduction in particular, so really nice!
You should get better finish if you run the lathe against the grain (the opposite direction), given how you dressed the wheel.
There could be some adjustments on speeds of both, but given that your lathe is belted is fine.
About using stuff on the wheels, sometimes it's used to make them coarser or finer than they actually are, but usually when in a rush and you don't have the proper wheel for a job in particular, which is always a better option.
Real good job with the grinder. Looking forward to see you using it for next projects.
All the best!
Thanks! The reason I ran it in the same direction as the rotation was because I don't have a reversible feed screw, so I had to run it that direction to feed in from the end. I guess I could have run the wheel backwards, likely making a big mess. :)
heh, then better to run it forward.
Strange though, these lathes use to come with tumbler-reverse gears or mechanisms.
Mine's has three holes at different locations on the headstock casting, rigth beneath the spindle. Depending on the hole you screw the idlers, you get forward or backwards spindle rotation.
I forgot to say you should try out mdf ("wood") wheels with some mild abrasive, either with water, oil, or even gluing it to the wheel works well to get a superb mirror finish (after the part being ground, that is).