The Micro Lathe: Putting the Spindle Together
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- Опубликовано: 7 сен 2024
- A second video on the micro lathe! In this video I show how I designed and put the spindle together. This spindle runs up to 7000 RPM and can take a ridiculous amount of transverse load (on paper -- there's no way my lathe could even load it up that much!) I haven't measured the runout yet as I haven't dialed in the position on my lathe yet (I have to keep taking it apart for RUclips videos and things!). If you wish to see more of this build and some of the exciting upcoming videos I'm planning, like and subscribe! You can also follow the build more closely on Instagram, at hlaps1990
im sick and bored as hell and just got the idea to design and build a mini cnc lathe and these videos are gold! thank you!
Bonne chance ! je me suis un peu cassé les dents dessus perso
Good idea to break in a newly assembled spindle, otherwise the extra grease is what causes it to overheat. Most common I've seen is running at a very mild modest speed (say, 1-400 rpm depending on bearings and spindle) for between 12-24 hours before running at operating speeds. This will allow the grease to flow where it is most needed and thin it out where it would cause the most extra heat. I've talked to a couple spindle rebuilding shops and they say it's especially important on spindles made for higher precision work.
Designer guy again. Great part.
Some things that I’d like to touch on, even tho you are likely aware. I’d run it unloaded for a while to monitor heat build up, see if it’s linear with respect to time. The thermal coefficient of the aluminum housing is double that of the steel rotor ( collet ). This will obviously increase the preload of the opposes cone bearings with thermal gain.
For rigidity, I like the idea of using standard lathe spindle practice, and piggybacking the forward cone bearing with another rolling element bearing for rigidity, say roller / ball. Also, maybe run oil inside with a flinger on the rear side with a labyrinth non-contact seal.
The only problem with that is the extra heat generated with the necessity of one contact lip seal. Not sure if two labyrinth seals are correct for that application . Anyhow, oil would help dissipate the heat better to the housing, it will get very warm at elevated rpm. Good logic.
Hi. I just stumbled on your channel and I'm very impressed. So far I've watched this one and the miniature turret. It looks great and I'm definitely looking forward to going through your other videos. I like your style - you don't cover up mistakes and have a subtle, dry humor. Keep up the good work!
Thanks!
the eccentric feature was a legendary thought
Thanks! Now I just need some way of marking it so I can repeatably remove and replace it.
Except that there is no real way for repeat-ability when he takes it out and puts it back in. I would end up getting it where I needed it, removing the entire housing and drilling into it and then threading that with a pointed set screw to hold it in place concerning where it needs to be, though he will figure this out if this lathe ever starts to be used.
um... also there is no grease seals on the shaft front and rear so if coolant is used that grease will become diluted and the bearings will go poof. Look at a trailer spindle and see how the grease seals work and also notice the good trailer spindles now use oil and not grease, and run much cooler due to this. Over all, very nice but I don't see it as a final version.
Excellent work. The sign of a true machinist. Loved the video and Thank you for sharing.
Thanks!
Very interesting build........from experience over the last 60+ years of my previous occupation I have found that a bearing in the end to end configuration like this one will run hot if the adjustment is too tight and cold if it's too loose.....after about 1/2 hour of running the nearing housing should only get warm...........progressively running and tightening the bearing will get you there.
Grease is supposed to flow and it will carry the heat to the housing. Some lathe mfgs recommend adjusting the after-break-in preload to achieve the right temperature. Colchester uses springs to tension some versions of their spindle bearings. It allows for expansion and contraction of the assembly. You can turn your too-large pulleys on a mandrel.
Check the break in instructions for a new lathe with similarly sized and type bearings. I would put a temp gauge on it for break in and heavy use. Most of the power of your motor will be going through that spindle and a fraction of that will generate heat. The aluminum housing should grow faster than the spindle thereby loosening the preload on the bearings. Some early Colchester lathe bearings use springs for preload and to compensate for temperature changes.
Some bearing companies have extremely detailed installation and lube info, loads, rpm. As I recall Timken may be one.
+Toby W Ya i know SKF and NSK do too
I just looked for a way to make a spindle to be attached to a wolfcraft drill press stand. This way, I can attach the drill to the spindle and hold the spindle instead of the drill to increase rigidity. I'm working on a low-budget project to transform a wolfcraft drill press into a hoppy metal milling machine. If that was a success, I'll continue to make it a 4-axis CNC 😆.
Subbed for the fasteners. So many, many fasteners.
All of the fasteners!
micro cnc lathe v2 full detailed build video please. ive built multiple cnc mills and your videos motivated me to design and build a cnc lathe. i'd love to see how you made this one in more detail, but sadly i cant. thats a really sexy ass lathe though. props. give the v2 lathe a second thought and maybe concider trying to make a mill someday. its a lot easier in my oppinion lol
Agree on the J belts.
Very smart to use a straight shank collet holder as spindle !
Yeah it worked out well! Prehardened with like 0.0002" of runout for $50 USD. Not bad!
Hello. Beautyful spindle 😍. I will be a similar. Greetings from Argentina
I just found your channel and binge watched all your videos. This is awesome man!
Thanks! I should have another one for you this weekend :)
hlaps1990 Looking forward to it!
super super craftsman , learning a lot from you
Dude, where did you go? WTF? We're getting blue balls here waiting for another video! You're channel is among the best.
Love the height adjustability
Cog belts tend to get noisy when tightened too tight. On cars you should be able to turn a reasonably long belt a quarter turn under fairly light pressure - unlike v-belts, no preload on the belt. You can also just loosen the belt till the noise goes away. At least thats the way they work on car engines...
Bolts hold things together by stretching until the elastic modulus applies enough force to hold things tight enough to keep things in place. I.e. not finger tight, not too tight.
You're probably right with the cog belt. I see the tension was too high now, but I've since used a J section belt which is much quieter and works quite well.
Tabletop Machine Shop , I have also seen flat pulleys used with an inverted cog belt. It would likely float at high rpm. Cog belt with servo drives on spindle and carriage could be used for CNC threading.
Great work on the TableTop Lathe with tool changer! I hope that you sell or post a plan set for building one.
Beautiful!
Lots of small fasteners should avoid distorting the housing as much as a few big ones. Tightened screws exert a force that spreads the threads radially as well as the more obvious axial forces which hold things together. A thread acts like a wedge.
That's a good point. I'd certainly rather have 8 small fasteners over 4 big ones :P
A heavy enough preload to overcome side forces should probably have a high flow of thin oil to keep it cool. There should be a break in period where it runs hot -run it for a half hour, then let cool, and then not that it does not get too hot. Square tooth timing belts on cars are noisy when too tight. Should have little preload. There were some belts that had more-rounded tooth x-section that may have been quieter, but I never had a chance to experiment. The cars I worked on needed a half twist between the thumb and forefinger. Since you have no valves to bend, you can fiddle with tension to your heart's content. Hope this is of some help in your somewhat different case than auto timing belts.
BTW, if you need a pressing die for installing bearing races, you can cut a bearing race in two in one side, say with a die grinder with an abrasive cookie, and it reduces the tension so you can tap them on and off of a shaft or a bore easily. Treat bearings gently, you can dent races and rollers/balls sometimes by wailing away on them. Pressing is best.
Thanks for the tips Toby! Next time I use timing belts I'll try your tension trick! I think my next spindle is going to use a light oil rather than a grease, as you suggested
nice idea with the excentrical cone :)
Thanks! If you can't make something accurate, make it adjustable!
>>> physically and mentally exhausting
Looks good, man.
I’d put tapered pins in the cap (drilled in situ). Looks like you have room for them, as if they were the 4th fastener in your row of 3.
You mean for alignment?
Amazing build on ur cnc lathe! great detail work, Would love to see a video of how much or how lil run out you have in the spindle assembled. also Im sure you know this already but you don't want to be in even the same county with a machine head coming apart at 7krpm. it was a lound "chonk" and a big hole in first the poly carb cabinet then the wall into the next lab. blood shed was involved.
+charrontheboatman wise words. Its limited to around 3500 at the moment, but even then i plan on adding some guarding around the belt and index disc. I'll do a runout measurement at some point, though the runout of the collet chuck the spindle was machined out of is allegedly 0.0001", so I would anticipate most will be from the bearings
Thanx for such a promp reply, I would love to see the tech drawing or cads for this build if your willing to share them, I am specifically interested in ur mods.
Nice videos thanks for posting it.
we would like to see more of this video.
Greeting from Malaysia.I subbed without hesitation.
+yustech i appreciate that! More videos are coming!
Many thanks
I love this video, but I'm a bit confused about the o-ring location for the grease retainer. It looks like the o-ring is pressing on the face of the spindle housing, but the bore that the spindle goes through is un-sealed. Would it not have been better to use a lip seal on the spindle itself? That would keep the grease in and the crud out. Am I missing something here?
Nope, you're not missing anything. You're certainly not missing an awesome name. The O-ring was a bit of an afterthought; you're absolutely right, a lip seal would have been better, my plan is to basically maintain a fairly low amount of grease that can pool in the bottom of the cartridge while not running, or get flung off into the bore walls while it is running. Next time. Next time will be better :)
Ha! Using a flag cutter sounds like it would take a REALLY LONG TIME! I'm wayyy to impatient for that. I would have used aluminum sacrificial soft jaws and just hogged the thing out. Looks pretty good, sound a bit like a turbo whine 😂
It took a long time, but it was one of those cutting processes that looked so cool it was just fun to watch. I wasn't super keen on sticking an end mill out 2.5" on the Tormach, but on a larger machine that would probably be the way to go.
I was actually thinking about how that would look. I really like using those, it makes such a good top suface finish! Haha I definitely get mesmerized my milling at times, stuff ends up taking me so much longer than it should 😂
Nice work man!!
Thanks!
This is sweet! How would you go about making an automatic chuck and bar feeder/puller? That would be killer!
can you tell me ,if you are going to use a spindle collet, why didn't you go for the next size up? maybe one day you will need to turn a bigger diameter...
This is cool! I want to make a mini 5C lathe over the summer actually. Would you be able to share design files with me?
You need to put grooves in the pulley to reduce the noise?
I think i would have filled the cartridge w ISO 32 spindle oil and provided a fitting for topping it off. What made you decide to go with grease instead?
I think just the lower speed and poor sealing. I think if I did it again I would do it with ball bearings and submerged in spindle oil, as you suggested.
You put the locknut on upside down, but hey, it's your project...
You have to leave room for the oil/grease film or the shear forces will cause excess heat. See brg mfg engineering manual. SKF and Timken are two, SKF may be better, but worth reading Timken too.
This channel stinks, of professionalism! XD you can tell this guy is a pro
More “a student of everything and a master of nothing” :p. Thanks though!
el reten queda mal, la ranura para llave queda tapado, el reten se quema a esas revoluciones y lo rodamientos no soportan esas rpm el husillo queda flojo ya que entra deslizante y no hay sujeccion del centro eso no puede durar mucho
you didnt go full AVE and machine the eccentric out of the ER collet nut
I yelled at the screen "No don't do it!!!"
its so annoying watching videos and knowing that the mistakes have already been done!
Link to that video please? I thought I had watched them all, but I gotta see this...
You've covered the collet flats with the oil cover...
I have a very thin wrench :)
Oh awesome idea. But for what kind of chuck or thingy to turn in is the ER32 useful?
Cool! the o-rings prevent the grease from leaking "radially" but how will you protect it axially? (not sure I make sense) What I mean is that there is no oil/grease seal lip against the rotating shaft (at least yet) :) right? very interesting!
You're right, I'm sort of relying on the fact that the grease will either pool in the bottom and be contained by the O-rings, or fly radially off the shaft. So far it seems to have worked!
I like your project and your delivery :) Keep it up and good luck.
Since you say you plan to make another one you might find this interesting.
Emco V10 lathes have a similar angular roller bearing design but they do a couple of things differently (not to say correctly :))
All bearing races are press fit, you absolutely can't install the races with bare hands - I use an M8 screw and small spanners with one finger pressure to do the job.
They run the spindle at max 3k RPM and they use hydraulic oil (sae 10wt/ iso 32 or iso 46) instead of grease. I'm not the bearing expert but 7k with large bearings and grease seems a lot to me.
They keep the oil level beneath the outer race so it doesn't leak out from gravity, but the case also serves as a gearbox so larger gears fling the oil all over the inside and they lubricate the bearings like that. They have seals very similar to yours on the outside, except there's no o-ring. Instead there's a small hole in the lowest spot leading any accumulated oil back into the case - there's practically no oil leaking to the outside.
It's hard to tell from the video but your preload seems a bit light. If memory serves torque of about 100g at 50cm lever (radially) from spindle should not move it from standstill but 120g should. That comes around to about 0,5Nm of static friction. I spin the spindle by hand while setting the preload, and the sound it makes changes when I hit about right preload. The other way to tell is spindle heat - about 30C rise above ambient is fine, more than that is too tight, less then that too lose. I don't know how that relates to grease and 7kRPM in your case.
They also use plain nut with a setscrew - no nylock. Makes it a lot easier to install. A small brass disc below the setscrew keeps the threads from getting deformed.
could you add a list of parts used, bearings, er collet. and if you got some design plans to upload? thanks
Very nice project, would you make the construction available so that the Micro CNC Lathe Automatic with Tool Changer can spread?
+Joel i'm working on drawings and a plan to release them, stay tuned!
too many fasteners looks cool thou.
+detoxrum yeah too many parts in general:p
great work!! will you add an index mark to the cartridge so you don't have to set the spindle height every time? and what about adding a grease nipple so you can grease the bearings without undoing the whole spindle? and (last question) can you still get a spanner on the back of the ER spindle so you can tighten to nut down?
I do plan on somehow marking the spindle so I don't have to keep adjusting it when I take it out for any reason -- maybe a nice brass arrow or something... A grease nipple would probably be a good idea, though I am trying to keep the grease coating pretty light (apparently too much grease makes things worse!). Perhaps in the next iteration I'll have a better seal and some kind of oiler. And, (last answer) you have astutely noticed a flaw in my grease seal ... it's a hair too thin for even the 1/8" wrench I custom cut for the job. Damn my decorative flair!
Great work! Really impressed. If you do this all over again, would you buy a prefab spindle kit as you shown or still do your own? Would like to do something similar for small robotics parts in my shop but can't decide if I should build something like yours or buy a much more expensive but almost complete machine. I'm a maker so building things is close to my heart :)
Hi Mikael, sorry for the late reply. The end of 2018 was busy :P. I have looked very seriously at Tormach and Syil's spindle cartridge kits, but, since I have the tools at my disposal and I love what I do, I'm happy to try my own. It pains me to say it, but buying machines is usually less expensive in the long term. I would definitely look at Tormach or Sherline before you start planning your own machine :P. Feel free to email me (hlaps1990@gmail.com) if you'd like to discuss specifics!
Greg
Hi @@TabletopMachineShop thx for your replay, I'll think I'll take the long version over mail :) Keep it up! Cheers!
@@TabletopMachineShop ...and would you consider trying to make an air bearing spindle next time for super precision and avoiding all the issues with lubricant (besides air) and (I guess) heating?
Grease for a high speed spindle? Wouldn't oil be more suitable? I'm wondering if the grease IS the reason it runs hot.
+somebody else ive since limited the speed to 3k RPM. My main issue here is that i wouldnt be able to retain oil, and even at 6 or 7k i think grease is acceptable. Youre totally right though, grease can make bearings overheat if theyre going too fast or even if you put too much in!
While replacing and running in spindle cartridges on a few machines in my past, I was taught by a friendly cartridge rebuild shop that the first few runs on a spindle are critical for grease displacement and bearing life. A newly packed bearing has grease in the way of the rollers that will get squished out, that grease squish-out friction will generate heat and warm the spindle. The idea is to mechanically throw/squish the grease out of the way but not allow the spindle to get warm enough to melt it and let it run off to someplace where it does no good. The grease needs to be moved out of the way of the main rotating bits but still close enough for surface tension to pull that thin film of oil from the globs all over the surfaces of the races and rollers. They recommended I run many low speed runs that last until the spindle gets warm, then stopping until completely cool, and repeat until the spindle does not get warm anymore.
For example on a Toshiba VMC75 spindle cartridge, the spindle was run at low speed (300RPM~ish) for about 15-20 mins or until warm to the touch then allowed to fully cool. This was repeated a couple times until it could run the full time period without getting hot. The RPM were increased and the procedure repeated until full speed was achieved. The low RPMs took a while but once done it went quicker through the higher RPMS. I think all this run in business is typically done for you if you have a cartridge rebuilt for common/still current machine but since the VMC75 was of the early 80's vintage and the local shop did not have a jig to mount it to, the run in was done on the machine.
Take that for what it cost you, this is not my area of expertise but it sure was fun. Good work and keep on making the videos.
Makes sense. I had to do a similar process to set the bearing preload on my ancient Atlas desktop mill and lathe. Everything is made out of rubber, and it all changes with the temperature...
Was thinking the same thing, ran a 20k rpm spindle at work and flood oiling was originally tried and the bearings were running way over temp, so oil misting was tried and no more problems.
Do you think this spindle/bearing design would be sufficient for a milling application?
Yes, but at speeds below around 5000RPM. If the spindle were vertical, I would also expect that you would need better seals than the ones I came up with, because the grease or oil would pool at the bottom
You mentioned that the spindle is eccentric so you can adjust the height and the cartridge form is to allow change of spindle easily. Are you going to stamp the cartridge with a witness mark for proper alignment or do you have some other idea?
I think a witness mark would work -- like once it's aligned so I can put it back in repeatably? Maybe even a nice brass arrow or something...
Hi there. I am currently a mechanical engineering student and i am designing a machining tool for milling. Your shaft arrangement is really good. I need to make modifications to the design to improve it and make it different. Do you have any suggestions on how i can modify this?
I would recommend making the shaft as long as possible (reduce moment effects) and using ball bearings. Have a look at my jewellers lathe video on the spindle. Id recommend two angular contact bearings for the front and some kind of floating roller bearing for the rear. Id also recommend specifying a torque to tighten the preload nut to. I did it by feel, but over-tightening will kill the bearings, and under-tightening will ruin the surface finish. Let me know if theres any specific advice you need. My email is hlaps1990@gmail.com
i don't think one set screw can transfer much torque from the pulley to the shaft, you also risk to scratch the shaft's surface. A better design could be using key or cut a D-end on the shaft and put a set screw there. Does spindle bearing better suit for high speed application like yours?
You're right: A setscrew is pretty weak for something like this, especially on a hardened shaft. Fortunately, the pulley is actually a shrink fit on the shaft, so that is transmitting most of the torque. The set screws are just there so I feel better :). The bearings can go up to around 7000RPM, however as another user pointed out, the rolling elements are so heavy that the acceleration is limited. The next spindle I try will probably have angular contact ball bearings. Thanks for watching!
@@TabletopMachineShop By shrink fit you mean you made it slightly too small then heated it to get it on and when cooled it's i.d. decreased and tightly grips the shaft? But at 5:52 it's sliding on loosely. Did you buy a 2nd pulley and bore it out to make an interference fit?
Hi!
Enjoy the build!
Thanks!
what? No zirc fitting to add moar greeze?
+ArcAiN6 i just open it up periodically and add grease manually
I am wondering how you will lock the shaft when trying to fasten the ER-collet, since you covered the flat section on the shaft.
Well spotted. I have a very thin wrench :P
3:06 so how is that taper made? Is that an inner race for the bearing that just presses into the hole or was the taper actually machined into the part?
Its a race that's pressed in -- tapered roller bearings come in 2 parts, a cup and a cone, so I just pressed the cup into the cartridge.
Nice job, thank you for sharing. What are the length and diameter of shank part of the collet chuck holder?
+Y _ CNC its a 1" shank and about 5" long (i cut it down to around 4")
Can please label the series with part 1, 2 etc.
Have you got the rollers running right on the aluminium surface? How's that going?
+Pete's Shredder. No theres a steel cup pressed into the aluminum :p
Have you had tried out J belt pulleys? I'm having the same issue with my mill spindle using GT2 timing belts and higher RPMs
I havent yet, but i'm hoping to get the pulleys finished soon!
hi,
nice video...what motor are you using for your spindle? Because i am planning of upgrading my motor on my Chinese mini lathe.
thanks
+cnchobby1 thanks! Im using a ClearPath motor from Teknic. Its a CPM-MCVC-3441 ... theyre a bit pricey but they work great!
Make a video on bearings! :)
Im planning on it! I need to figure out a way of doing it without powerpoint!
Hello everything is fine? My name is Everton, I'm from Brazil, Campinas - Sp, I would like to know if you can send me the CAD for this project, so I can execute it here.
What's the runout like?
hey, please include a time lapse of the machining?
sanjay dubey i plan on doing more machining scenes as i go! Unfortunately for the first few videos i didnt take any footage when i was making the parts :(. Ive been taking a lot more now!
hlaps1990 Cool, I appreciate you for sharing your work. Could you suggest literature about how to design a machine like yours?
+sanjay dubey i like "Shigley's Mechanical Design" for all of the strength calculations, and the skf website has tons of bearing info!
where did you get the pulley? fidgets.com?
Your thread mill was a good idea the setup is what sucked next time use a V block!
+Bub Dog's What do you think? Agreed!
How did you lubricate the bearing?
I used a high pressure grease that I manually added before assembly. It seemed to work well, but an oil would have permitted higher speeds.
What was the run out?
Did you make this lathe yourself ?
Yep I started at first turret and built outwards. Not the most efficient way of doing things :P
Toi muon mua 1 cái,cho gia duoc khong?
Needs more fasteners
Moar fasteners!
What is this fidgets website you keep talking about I can't find it all I find is a company that deals with fidget spinners and that bs
Phidgets*... Probably not the best company name for word-of-mouth
@@TabletopMachineShop well I know I saw the website in one of your videos but couldn't re find that video
Can you building me a descent and compact 3 axis c
Can you build me a decent compact three axis CNC machine with a tool changer
So whats the deal here were you developing a board or software or proving a machine could be slapped together for cheap?
The mechanics of the machine all functioned but you didn’t put the effort in to make it rigid or focus toward finish quality. You’ve shown your capable of the mechanics yet short cut the necessary features.
Id like to know the story behind this because a little more work with better materials and you would probably have 1m followers on RUclips.