The Jeweler's Lathe Part 1: The Spindle

This is a sort of medium-length project I am taking on in preparation for some longer term projects I want to start in the future. I consider this a bit of machine design practice for my next big project. I'm calling this a Jeweler's lathe; a manual lathe that is laid out for small to mid-sized manual turning of ornamental shapes. This is part one, where I design and make the spindle. All CAD and drawings can be found on my Patreon.
Instagram: hlaps1990
Patreon: www.patreon.com/hlaps1990
Music from Soundtrackuniverse.com

[@asid61]

Wonderful video. I love hearing these engineering explanations! Definitely going to use some of these tips for my own lathe.

[@joshwarner5676]

Awesome video. Definitely a well explained process path from cutting requirements to bearing choice and shaft design. Super cool to see this whole process, and I'm looking forward to the next video in the series.

[@TabletopMachineShop]

Thanks Josh!

[@robmckennie4203]

For the benefit of anyone who was confused, the unit Ws/mm^3 is a bit messy, but it makes more sense when you break it down a little. A watt is just energy per time, 1 joule per second, so the seconds cancel out, giving J/mm^3, which is just the amount of energy required to remove a particular volume of material. The reason the more complicated unit was used is because it makes the working out in later equations easier

[@johneric3886]

Excellent video, very clear and thorough communication skills.

[@Aletaire]

Never thought about the making of a lathe before. Pretty interesting and well explained process on calculating the parts you need. Good video.

[@TabletopMachineShop]

Thanks! There's a few intermediate steps that I didn't show, but I want to make a video about bearings that will hopefully contain all of that. Thanks for watching!

[@jameskourmadas]

Really appreciate trudging through the design engineering equations on this! Most DIY machine makers on YT just trial and error everything.

[@TabletopMachineShop]

Thanks! I really try to strike a balance on and off KZbin between trusting my gut and taking a bit of time to do the calculations. I don't think I've ever had a calculation reveal an imminent failure due to my tendency to overbuild things, but it certainly makes me more comfortable when using stuff I've made!

[@user-pr2fy2oi5k]

i love your smart way

[@mr1enrollment]

Nicely done, I am an EE learning to do metal working so I find your engineering background pleasant.

[@TabletopMachineShop]

Thanks!

[@robmckennie4203]

I only just saw this channel for the first time, all the projects you list sound super cool. Home made machine tools are a particular interest of mine, I subscribed and I look forward to seeing more cool projects

[@Freetheworldnow]

A novelty on KZbin: SS machining! Verry refreshing. You have a great lathe and well tooled by the way... Very interesting project. I will view your next episodes on this great lathe building project. You seem to have quite some knowledge in various fields. Thank you for sharing.

[@thomasblackwell9507]

FANTASTIC! You actually engineered this lathe and you did it extremely well.

[@TabletopMachineShop]

Thanks Thomas! Ive been a little light on the engineering for the last few videos because they were mostly structural components, but i may need more conventional engineering for the axis components

[@Mister_G]

I know it's old, but it's an excellent video. The calculation bit was very well presented and succinct. Looking forward to watching the rest of this project.

[@teddytavernier7522]

would love to see another video going into calculating the spindle size, theoretical deflection ect! Great work, keep it up! You do a great job of explaining the calculations and showing your decision making process.

[@TabletopMachineShop]

Thanks, I'll make sure to keep that in mind! I foresee more spindles in my future...

[@bobiggins8027]

excellent and informative, love it when youtubers play with the math

[@TabletopMachineShop]

It's certainly hit and miss, some like it, some hate it. I don't prefer it, but as with the whole process, you can't really skip it and have everything make sense !

[@awc.sorensen]

Looking forward to the rake storage video

[@TabletopMachineShop]

Maybe it will involve machining and clearpath motors

[@stefandebruijn3167]

Whoa. Very nice video! Do you already have the bearing video as well?

[@thomaslizon2594]

Great content, the first part is pristine clear and the machining is perfeçt (I hate 6061 since I started using 2017A). This stainless shaft is a beauty. Will this inception of making a lathe on a lathe lead you to make a nano lathe with the jeweler's lathe? I hope so! Best. Thx

[@beachboardfan9544]

Ooooo yea, nerd it up, then fiddle with shafts!! 😉

[@TabletopMachineShop]

Business as usual

[@sachinkumarbadiger3541]

Could someone reply.. which is the best material for heavy duty machine spindles especially for a high precision and industrial grade machinery.

[@mattinkel7342]

Make all the machines!

[@TabletopMachineShop]

Finally someone who gets it!

[@mattinkel7342]

hlaps1990 ...of course! I just built myself a die filing machine ... tumbler polisher will probably be next ..

[@TabletopMachineShop]

Put a video up on it!

[@LaukkuBah]

Nice informative video and quality machining porn, though your voice was a lot quieter than the other sounds so I had to adjust the volume all the time.

[@TabletopMachineShop]

Well I do speak softly, and the machines are loud, so you're pretty much getting the real experience! Just kidding. Good point, I have to work on my video editing :P. Thanks for watching!

[@ExtantFrodo2]

I like how you interrupt the parting to camber the edge while there's still material to turn it. Efficient!

[@TabletopMachineShop]

I started doing that when I saw someone do it on KZbin actually!

[@dazaspc]

Ahh a couple of motorbike wheel bearings. Cant go wrong with those, Cheap to replace and for their size very highly rated. The needle roller is tricky at speed re lubrication and fit there is virtually no room for error. If your grease is to thick the elements will skip. Some NBU-15 would be the heaviest that I would use in there. If you have trouble with the needle roller just go to a single bearing like the front and give it an 1/8" end float clearance in the housing. Also a tight clearance fit on the od 0.005 ~ 0.015mm. You use a O ring or quad ring to hold the od and it will be fine. As for a belt drive may I suggest something a bit different? Try a flat microV belt drive. A 4pk should be good for 1.5 kw way more than you need. These are common automotive gear and will work well in your application. These are quiet and don't consume much power. The pulleys are easy to make and if you don't want to you could just buy a couple of inner tracking pulleys of a serpentine belt drive of a car. You would have to bush them to make drive pulleys. The last ones I bought cost $15 each Australian and a 4 pk belt was only $10 but these were automotive sizes. You could go down to your local pick a part and scrounge some idler and or alternator pulleys pretty cheaply. There is no problem running a 4 pk belt on a 6 or 8 pk pulley. Timing belts don't slip but introduce harmonics to the cut and will be noisy at speed. V belts slip to much, use a bit more power and need to much tension on small pulleys. Cheers

[@TabletopMachineShop]

Hmm motorbike wheel bearings... I didn't know that, but that's probably why, of the 3 commonly available 20mm bearing sizes, they were the cheapest by far. I think they were like $13 each for ABEC-3, and SKF no less. I'll look up NBU-15, thanks! All in all I would sum up the needle bearing experience as "sketchy", so I may try out just using a deep groove ball bearing next time like you suggest. I believe a J section belt is a micro V belt, but I'll have to look at automotive suppliers for cheapies. I agree with timing belts -- they sound like chainsaws at full speed :P. Thanks for the input!

[@msclawnmaintenance]

That was great man. Hey what about the other lathe you where doing. I sure could use a auto tool changer lol

[@TabletopMachineShop]

Still goin! I'm sort of clearing out an area at the new house for it to live. I'm getting some funny voltages on the tool changer board so I may re-solder one. I don't mind it not being perfect, but I'd prefer it didn't try to change tools randomly!

[@Asaadomar]

Great video. Thanks for sharing. I am wondering how this design will handle back facing or lt hand turning?

[@TabletopMachineShop]

Good question. The spindle is, so far, only held in place in the +Z direction with the press fit. I may thread the lip at the front and use some kind of retainer there to hold everything in place, but, for a 100-200N cuts I don't think it will be a problem:P.

[@Asaadomar]

hlaps1990 this was my guess. Thx for replying 👍

[@madsbruun8423]

Hi great content!!! Would you mind sharing your source to theese calculations. The specefic energy tables, your power calculations and cutting force assumptions. I'm an engeneer so dont mind math heavy explenations :)

[@MadHatter123456]

Awesome! This very much confirmed my gut-feeling about the motor, I've gotten myself a 440W motor for my lathe. Love your videos, keep it up! Very curios about how your new lathe will turn out!

[@bobweiram6321]

What happened to this channel? There hasn't been a new video in over a year. It was one of my favorites.

[@Made2hack]

Hi, You mentioned axial loading on the choice of bearings you used. Can pillow blocks be used for holding a shaft? I understand they are used primarily for radial loads, almost exclusively. Do you know if two pillow blocks can be used to hold a shaft? Thanks,

[@TabletopMachineShop]

They should be able to... they are usually compliant in angle to compensate for misalignment, but they are axially constrained. If one bearing is secured along axially on the shaft and the other one isnt it should be fine

[@Made2hack]

Thanks for your reply. I've noticed that many lathe heads tend to use two tapered roller bearings or at least that seems to be the recommendation.

[@lewisheard1882]

Like the Vids, maybe a bit too much lathe work without commentary, found the opening very interesting though! One this I will say, normalizing the sound between the clips would be really nice, almost blew my heads out a couple of times :) Keep up the good work mate, and good luck in the new abode.

[@lucgyre9268]

Are plans available for this ??? awesome job :)

[@TabletopMachineShop]

+Luc Gyre hi Luc, thanks! There are plans available on my patreon. I upload them by subassembly, usually a few days after the video is published

[@janbeck8269]

Thanks for the video! Where did you get the bearing shims?

[@VId_Kok]

Google DIN 988.

[@TabletopMachineShop]

I got mine from McMaster-Carr (PN 98089A244)

[@janbeck8269]

Thanks!

[@madsighntist14]

WHATEVER you do, forget about "Any" of those Thumbs Down !!! I have Watched this Twice now, and am willing to LEARN More, so my Machines Run Better !!! Great job on the Simplifying, But PLEASE, always give the Detailed end of it. I have worked with several PE's in my life around Machines and I know Some who will not "Listen" to Anyone one ~without~ a PE Credential behind their name, and then there is "My Mentor" Sadly, Deceased. HE would always Listen to me, and Would ALWAYS State, "if you Think of something to make it Better, I Will LISTEN. But what does "He Know", Oh, He held the FIRST New Patent for a Product, since the 1860's ! ! ! I Must leave him at "Anonymous" by his request when I worked for him. (But he is Known INTERNATIONALLY in his Field). Keep On doing what you're​ doing, And Newton He did make good Fig Cookies !!!

[@TabletopMachineShop]

Hey thanks! I try not to sweat the thumbs downs :P. If you put a video of a puppy falling asleep in a slipper with a kitten you'd probably get some dislikes. I try to stay open to new information or opinions, I do have a bit of a background in machine design, but there's so much to know and so many tricks that they don't teach in school. Your mentor sounds awesome. I've had a few mentors like that... They're probably a big part of why I love this so much:P Greg

[@nraynaud]

Nice work. Aren't the oblique contact bearings designed (ie ground pre-loaded) so that when the inner race and the outer race flange are co-planar you have reached the manufacturer preload? I think I heard Robrentz say it on a podcast.

[@GLKeeney]

nraynaud1 Some are. Those AC bearings ground as sets or “universal” can be had with a specific preload ground in. When pressed together preload is automagically established. Other, less expensive, bearings still rely on shimming to achieve proper preload. The whole procedure makes me nervous.

[@TabletopMachineShop]

George Keeney nailed it. Im just a poor boy, I have to shim my bearings myself :(.

[@TabletopMachineShop]

It makes me nervous too--That's why I went for such a light preload. It really doesnt take a lot of wrenching to totally ruin your bearings lol.

[@rcdieselrc]

For the time and materials involved in this project a pair of 7204 P4 isn't much, especially on ebay.

[@TabletopMachineShop]

+rcdieselrc ive come to distrust ebay bearings... apparently theres a huge counterfeiting industry for bearings... i guess i couldnt mentally justify the cost considering the kind of cutting ill be doing. The ABEC 3 bearings i got seem to be working well... 0.0015" runout before grinding is respectable

[@PhaseConverterampV]

Your dads lathe? You are using top end tooling $$$. Sandvik Devibe bar? Nice

[@stephenbongiorno8131]

Does anybody understand how the preload works? The nut is pushing on the needle bearing inner sleeve, which had what ended up being a press fit on the shaft. Is the nut doing anything here?

[@arturocaballero7208]

I think you're right. The preload is set by the shims. The bearings being press fit makes the preload fixed. The spacer and nut contribute nothing to the preload. The reason I came into this video was looking for a way to set the preload for angular contact bearings. I found this pdf which says the bearings should be a sliding fit in some mounting schemes: mrosupply2-dyn-documents.s3.amazonaws.com/product_documents/10/100KSF/installation.pdf

[@richardwesterfield4578]

are there any plans, drawings or a parts list coming ?

[@TabletopMachineShop]

+richard westerfield hi Richard, i put the plans up on my patreon! Im hoping to stay on top of the drawings for this build

[@markhoeflinger1040]

its been a while since you did this video, so maybe this dont apply any more....... You have a nice lathe and carbide tool , the lathe is capable of cutting/ turning .100-.200--.300 cuts, in slower spindle speeds and slower feed rates.......also, if the tool bit is turned at a 45 degree angle the tool will cut better when taking these very heavy cuts....... how ever, while rough turning a piece, it will get very hot and around .010-.015 should be left on the diameter to allow for cooling and to finish turn the diameter to size........anyway looks like you did a very good job...

[@lvengineerable]

nice video. What happened to your other lathe project though?

[@TabletopMachineShop]

Still going! I'm just bouncing between projects as I wait for parts or patience :P . I'm getting a spot ready in my new "shop" area for the lathe so I can finish it off

[@lvengineerable]

Cool. Can't wait to see that

[@321sparx]

Coffee wheres the coffee...in the startup you had things to do but no coffee,i have coffee breaks all day....actually i work between coffee breaks great video,gonna subscribe for more thanks!

[@TabletopMachineShop]

Thanks! Coffee keeps this whole operation going :P

[@jacksteel9837]

would you be able to sell them on the market? i would be happy to team up :)

[@johnwalters6800]

Where did you purchase the bearing shims.

[@TabletopMachineShop]

I got them from McMaster-Carr

[@RobMan414]

+1 Sub! Not sure about anyone else, but I found your voice volume too low compared to the machining. Other than that, really enjoyed it, keep it up!

[@TabletopMachineShop]

Welcome! Yep a few others have mentioned the voice thing -- I'm certainly going to work on it for upcoming videos. Thanks for watching!

[@Alex-yq2tf]

Do you use any grease for the bearings? Why?

[@TabletopMachineShop]

Most sealed or shielded bearings come with oil or grease in them already

[@reddog69c39]

Did you use oil.

[@tonynchrissy420]

Now I feel slightly dumber because I was completely lost on the math aspect😨 but still interested and amazed😀

[@TabletopMachineShop]

Thanks! If you think theres anything i can explain in more detail, let me know! Im thinking of making a video on bearings, and it would be great to know how deep to go :p... i used to be a teaching assistant in machine design, so im happy to break it down pretty far lol

[@tonynchrissy420]

I would like all the information I can get because I am very interested in making one of my own because I am in need of a good piece of equipment and I would love to be able to say I am using something that was built with my own hands. My experience in this area is minimal at best so I am trying to absorb everything I can at this point until I can save up the money and knowledge needed to purchase the equipment necessary to begin construction on mine. Also I am going to be starting to gather info on a 3d printer and mill. So any information you can provide would be greatly appreciated. I am sure this is going to be a very long process and I am going to run into snags along the way but I am very determined to accomplish my goal. Thank you in advance for any and all information!!!

[@pauldevey8628]

Insulate the shed and put in some heaters on the ceiling and it will be nice in the winter.

[@TabletopMachineShop]

Good idea!

[@pauldevey8628]

The "Dog House"

[@holypizza1]

can you provide that excel sheet you mentioned?

[@TabletopMachineShop]

Crap I don't think I ever shared that. I'll figure out a way of making a google sheets of it and put it up on my Patreon as a freebie!

[@benalexander7388]

Have you measured spindle run out yet?

[@TabletopMachineShop]

+Ben Alexander its about 0.0015".. im probably going to grind it in though

[@koplandavid]

why does tha nut have so much play?

[@TabletopMachineShop]

I was a little aggressive on the thread cutting I think..

[@MetrologyEngineer]

What did you go to school for?

[@TabletopMachineShop]

I went to school for mechanical engineering, obviously not machining :P

[@EitriBrokkr]

so much enginerding, so little experience, don't get me wrong you do beautiful work, but I think you missed a couple classes when you were getting your degree for example, Stainless likes to gall like a mofo 101, and Galvanic corrosion 220. excellent spindle design btw, but with the addition of a spindle body cap you could have avoided needing to press the bearings in. which is usually avoided at all cost in spindle design. also that nut should have some kind of distortion locking feature, ideally a spieth nut type design or something similar.

[@TabletopMachineShop]

I won't pretend I've been doing this for 60 years or anything, but I've certainly been out of school for a few years now. Most of the classes I missed in school were in economics :P. I definitely agree that 300 series stainless steels gall like crazy, though I was pleasantly surprised by 17-4, even in the softened state. The plan was originally to harden and grind the 17-4, which would be absolutely mandatory if this were ever going to be used by someone else, but having evaluated the equipment at my disposal and the cost of jobbing it out I gave it a miss. Is your point about galvanic corrosion regarding the stainless steel fasteners? I do usually avoid them unless I'm anodizing (which these parts were), but I've never really had a problem in relatively thick parts. I've seen spindles with the bearings in caps and with the bearings pressed in -- do you just mean that it's easier to swap the bearings? I don't see myself doing that. I do have some experience in machine design, however I have zero professional experience in high speed or precision spindle design, so this was very much an experiment. I won't argue with the distortion locking nut, though the nylon locking element in this one seems to be holding up. Thanks for the comment! I hope I didn't sound glib or anything in my response. Greg

[@EitriBrokkr]

not at all, I was more worried about the bearing spacer, which I believe was aluminum, maybe I missed it and it was SS, also I should have watched additional videos and realized you anodized the whole thing, that should help tremendously. you wont distort bearing tolerances with a spindle cap. plus your right the benefit of disassembly. with the right design you can use the bearing cap to capture the nose bearings, and have the critical dimensions on the cap, which is way easier to screw up, remake, or adjust dimensions, than internally boring steps in the bore. your spindle design it awesome, I could argue AC bearing purely on the fact of, because AC bearings :) but other than that I've seen a lot of high speed ballscrew set ups done the same way. a spieth nut axially clamps the threads like well the way thready are designed to be stressed. I wouldn't buy one, they cost about a billion dollars, but you can make a similar thing in 2 pieces pretty easy, making a small one in one piece is a pia, they're really superb in allowing you to set your preload right where you want it, an then locking the nut in that position. and on the business side they stay nice and flat unlike some other "clamping nuts" I finally got sick of the crappy double lock nuts on my G0704 and built nuts for it. next time you build a machine look into it, you'll never go back to anything else.

[@pyk_]

A little energy over a long time is greater than a lot of energy over a little time?

[@TabletopMachineShop]

A little energy over a long time is less power than a lot of energy over a little time.

[@pyk_]

@@TabletopMachineShop I was pointing out how non-intuitive that is. Sorry I got it backward.

[@Raccoonsareawesome]

25:25 is REALLY dangerous, if you care about your fingers i would recommend to keep them away from the chips.

[@TabletopMachineShop]

Hi Daniel, Fair enough, i was certainly paying very close attention, and it's not as close as it looks from this angle, but yep, I should have used a stick in the bore to catch the part.

[@chuckhuff7123]

Can't hear you

[@kevin_delaney]

"Death ray development" "Dangerous stuff" 😃 I wonder if you just like throw shit in your videos to see if anyone notices 😂 like "converting aluminum to Tostitos" hahaha your sense of humor is very entertaining

[@TabletopMachineShop]

+Kevin Delaney i put lots of little things like that in my vids... i think it helps keep me entertained when im editing. Im glad somebody notices :P

[@kevin_delaney]

😃 Well don't stop doing it because it's hysterical haha I do the same things. I leave future me something whether it's funny or helpful, totally forget about it and I'm like "Oh what? Haha thank you." Sometimes you gotta create your own fun :)

[@richardwesterfield4578]

i joined your patron web site. now i can not log in they took my money they ask me to reset my password i wrote back how can i do that not know my password it is the worst web site for getting information you can not get in touch with a human being can you help me? thank you Richard Westerfield

[@TabletopMachineShop]

+richard westerfield Hey Richard, until thats resolved just PM me your email and i'll send you the CAD. Unfortunately I don't know how to fix it!

[@richardwesterfield4578]

[e-mail]

[@lazyh-online4839]

richard westerfield you might want to stick to pm when sending personal info, otherwise anyone can see your email address which could cause you all sorts of trouble with the kind of people you find online.

[@AppleAssassin]

Please no more 13 minute powerpoints

[@TabletopMachineShop]

Ugh I agree. I don't like watching Powerpoint on KZbin either but I can't think of a better way to show calculation. If you have any suggestions i'd love to hear them, otherwise I'll try at least to break things up more in the future.

[@anameisrequired3729]

I found the calculation very helpful. It's easy to skip over parts in the video if you don't care for it, but if the information isn't there, you can't get it. I'd love to see more theory videos.

[@Thunderbelch]

I'm with @A name is required. Alternatively, you can put the calculations etc on a website and link to that from the video. But the video must at least include a qualitive explanation of the design process. Viewers have the option to skip the parts they don't like, or to go watch a channel that just shows pure machining and no useful design & engineering content.

[@user-pr2fy2oi5k]

no, don't remove 13min power point. i really hard understand english speech, but can read and understand your subs or slides, especially when you talk about calculation. so if you have much looks from other countries, don't remove power point slides)

[@JShel14]

I actually enjoyed this layout. It was really easy to follow and useful to me for my own calculations.

[@tomthumb3085]

Total waste of bandwidth. If I were to build a lathe of any size I would not design it merely to machine one size of material at a particular cut. Too much waffle for irrelevant data in the real world.

[@mechanicalmeddling8336]

Somebody didn't get their coffee this morning.

[@1berkut]

he is not designing it to machine one size or one cut he is using the maximum material size and maximum cut to determine how strong the lathe needs to be

[@Aletaire]

I think you're misunderstanding the wording.

[@TabletopMachineShop]

I love waffles. Perhaps I didn't make it clear that this was sort of my "most extreme case" of cut. I calculated this in an excel sheet and played with the cut parameters a fair amount to make sure everything was up to snuff. Obviously this isnt how DMG-Mori predicts their spindle loads, but its a good starting point.

[@mechanicalmeddling8336]

Watchmakers lathe?