Mini Metal Lathe

Hack a power drill into a mini metal lathe with precision speed control.

I used a couple of broken power tools for the drive components in this mini lathe.

It features a powerful motor and small size.

The speed control hack is shown in step 5.

The video shows a functional speed test of the lathe. There is a vibration from the motor coupling which is quite evident as the speed increases.


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I have added another video in the more tweaks step.

I am starting to think that I need a laser etcher to make a micrometer tool holder for the next round of tweaks.
 

Step 1 Materials

There are some specialized items needed for this Instructable.

The base materials are from Bosch Rexroth. The extruded aluminum base, t-nuts, inside brackets, end caps are all Bosch Rexroth. The extruded member is 45X90 and 14 inches long.

The support blocks are from VXB.COM Part number WH12A

The Skate bearings are form VXB.COM Part Number 608ZZ. Yes I know that these are not taper bearings (ideal choice) but they do work for this application.

The flex motor couplings and rubber spider are from PrincessAuto.com

I used a 12V DC motor from a Black and Decker cordless weed trimmer

I used a variable speed switch from a Milwaukee 18V Li-Ion cordless drill

The rest of the materials are presented as needed in the instructions.

Comments

[ninteriorplasterer]

This is seriously cool.

The first thing I thought as soon as I saw it though was this :

Hmmm... so theres something I can do with that old tile cutter I got from the local dump for $5 - I was thinking of dismantling it to use parts on bicycles / art projects... and it just so happens I have an old drill laying about - now, just to make the time to do it... maybe next winter (southern hemisphere).

Seriously - look at a tile cutter, then look at the lathe... ready made?

This picture is from the first result on google image search and is a Husqvarna TC470 - credit where it's due and all

[lloydrmc]

Wow - no kidding. What an imaginative hack! Make sure you take pictures so you can post an instructable.

[htbeef]

Don't want to sound like a commercial, but a company called Misumi (full disclosure, I work there) sells a ton of mechanical components (shafts, bushings, bearings, bearings in housings, metal plates, brackets, etc.). They have a catalog that specializes in parts used for assembly automation. But, what makes them probably most useful for the Makers out there is that there are no minimum order quantities (you can order one of anything in the catalog, including springs washers, screws, bolts, and nuts) and you can order everything online with a credit card (they deal directly with the end customer). I only mention this because I saw many components that can be purchased directly from the catalog (bearings in housings, motor mounting bracket, extrusions, hardware for the extrusions). Plus many of the components are "configurable" (with the extrusions, for example, you purchase them in 0.5mm increments in length anywhere from 50mm to 4000mm), which means that you don't have to modify them when you receive them (the motor mounting bracket, for example, would come with all of the holes in the correct locations already).

Again, I didn't want this to sound like an ad, but I think that this catalog would be very useful for many of the Makers our there.

[lloydrmc]

Nothing even slightly wrong with presenting this information, given your disclosure, and the perfect topicality for this project - more so given your specific examples.

For my part, I'm very glad that you did, as I can see that, at some future date, i may well have use for what they sell.

[eBandit]

Cool, I was thinking of making one of these mini lathes using a linear guide from Misumi. I was checking their site and the linear guide (not sure if need heavy duty or not) "may" make a decent lathe bed and also the carriage part both???

[doxsys]

Misumi makes very nice parts, and they're accommodative to hobbyists. I've ordered from them a number of times and haven't been disappointed yet.

[overblast]

Thank you, just signed up at MiSumi.

[MattyBoJangles]

We use Misumi parts at work in our designs. Very High Quality parts.

[rgeelen]

i like the way he says that he doesnt want to look like a advertisor but stil advertiser neverless its still very useful, i mean im 16 yrs old and even i understand it all. so thx for the nice non- advertisement.

[marg_nukem]

i have to disagree on that, I see advertisers all the time and i can tell for sure when i spot one, he never mentions prices or why they're product is better not even a single link to a webpage or email, i really think he did it on good faith, actually i didn't knew about misumi and it help me cause i always struggling to find parts like those... just my two cents...

[MatthewEnderle]

also McMastercarr has a huge variety of parts. I was going to order from there, but then I cancled my 10W Laser cutter. At 16 i can't get to well of a paying job to satisfy the projected cost of $1500.

[lloydrmc]

Nowadays, if you're 16 and can get any job at all, it's a miracle!

[MatthewEnderle]

Not quite... I'm trying to get a job in the Information Technology and other outdoor labor forces (landscapeing, Excavating - which i did last summer, and anything else). And my dignity refuses to work in a large chain store or fast food area.

[lloydrmc]

Ahh, dignity! I have forgotten what that felt like! :)

[brainpuddl3]

Thanks, looks very useful!

[TT01Fanatic]

Hey, just found this instructable, lemme first say this is some GREAT stuff! I've always wanted a mini lathe, never realized how easy it really was. Anyways, I'm wondering how the finish on the part is after taking it out of the chuck, it looks as it the allen screws would scratch the surface, and with even my little amount of experience in this field, they have done the same for my pieces. Do you have an alternative that might correct this?

[mwhite16]

You could use shims to prevent marking. (Very thin pieces of metal, like paper thin, or up to 1mm thick), which would absorb the scratching, but still provide enough clamping so as to not allow the work to spin in the chuck, which produces terrible marks.

If you use aluminum shims, they can be a bit thicker, but provide good grip. Try any machine shop for some scrap to use as shims, or buy a small sheet of very thin steel or aluminum to cut up and use. One tip for using shims though, is to have one shim per chuck jaw, don't try to use one piece and wrap it all the way around. It can make it sit unevenly in the chuck, and not spin true, and use the same thickness at each chuck jaw.

I hope this helps.

[clazman]

Very innovative.


haven't read all of the comments except for the one that mentioned plastic screws.

Why not just use brass screws?

I had an occasion where steel screws were riding in a groove in a mild steel shaft and creating an slight burr on the groove edge. This burr created havoc with the aluminum component that slid over the groove. I simply replaced the steel screws with brass ones and problem solved. I have seen very little wear on the replacement brass screws and even if I did the replacement of two crews was much cheaper than the replacement of the piece of steel.

This situation, I might add, was a component of a $27,000 power chair that my wife requires to make her life less restrictive.


Again, a nice piece of work!

[Rockil]

i use brass shims for just about anything that i do not what marked up or try useing a brass button on the end of the screws

[Random_Canadian]

Thanks. I am working on a new design that should give better clamping without the marking.

[ironsmiter]

as long as your pieces will hold up to it...
try brazing tiny ball bearings to the dimple in the end of your set-screws ;-)

Another thought...
Since this is a TINY lathe, and parts don't need a ton of clamping force, even at high speed, epoxy/glue nylon puck onto the end of the set-screw. or even use plastic screws!

Or, pay-to-play, using y ideas... that I now see aren't nearly as novel as I first thought.
http://www.lexingtonsetscrews.com/

[Bill280]

I know I'm a little late to the party, but why not "decouple" the motor entirely, set it on it's own stand behind the lathe and run the lathe with a belt ( I know that's how a lot of factory lathe are made -- probably for a reason). Keeps all the motor vibration away from the lathe and eliminates having to align the motor shaft with the lathe center.

[jeffrey4283]

This is great! A well executed project. I plan to build one of these as soon as I'm done with my 3D printer.

[halfmumi]

1 word: Flawless................

[throbscottle]

This is brilliant! I love the way you have used nuts and bolts to make a cross slide - shows how you can use cheap and widely available parts to make something fairly sophisticated without precision tooling. shame my blowlamp isn't powerful enough to braze anything that big, since it's only a normal plumbers one. This is extra interesting to me because I've just been designing a wooden cross slide for my own mini-lathe project, so it's nice to compare methods (mine has a turntable to cut angles, but I don't know if it will be solid enough until I get round to actually making it).

[bulent123]

good work.

[pietzeekoe]

How much was that aluminium profile?

[Random_Canadian]

i think i paid $90 for a 10 foot length. but that was about 7 years ago... check eBay for scrap pricing, if you are local to Calgary i have some small sections that I could give you.

[Hessian Nerd]

Please extend that output shaft and put a second bearing on it. Dont abuse your couplers like that, they will wear faster and the forces will prematurely wear your motor bearings as well.

[motor]=@=#==#=c

@...coupler
#...bearing
c...chuck
=...shaft

[Random_Canadian]

Yes I agree, that is an excellent suggestion.

I have been experimenting with this as a way to further reduce the vibrations with some success.

When I get the edit function corrected I will be adding what I have done to the tweaks section.

[ironsmiter]

Thought about this coupling for a few hours after reading the make.com article...

and think I'm going to cheap out, and use my thrift-store off-brand "Magic Bullet" for the motor AND coupling. Sure, it may only last a few years of moderate use... but before then, I think the Gingery method will come into play, and I'll use the lathe to make the parts for a BETTER/MORE ACCURATE lathe to replace it.

Nothing says Maker like bootstrapping yourself to a high precision workshop ;-)

[M2Field]

Why bother making a three jaw chuck?

For just $15 including postage you can buy one with far better centering capacity on ebay that will accept up to 3/8" material.

Use a second one on the tailstock for boring!

[Random_Canadian]

I appreciate the info. The Lathe chucks are far larger(usually 3 inch) than this small size will allow for. If you are referring to a drill chuck this is not usually the best alternative since the jaws are not independent and it will not hold flanged materials. centering can be a problem.

The drill chuck for boring is an excellent idea though.

I hope that this helps

[M2Field]

I should have said "Jacobs Chuck". My bad.

The fact the jaws do not work independently makes centering a breeze. Imagine if your cordless drill did not have perfect centering every time. Centering is never a problem, in fact it CANNOT be a problem!

Compared to your independent 3 screw check, that must take endless tinkering to get a piece centered a Jacobs Chuck is a dream.

I cannot address your issue with "flanged" materials. I do not know what these are.

[ironsmiter]

:-) so I take it, from your "It CANNOT be a problem" comment that you've never had to re-adjust your drill bits because of a serious off-center wobble?

Granted, on larger bits, it's not a problem, but smaller bits CAN and DO slip between the jaws, and if you're not paying attention go wobble-wobble-wobble-Wiiiiinnggggg-clatter-clatter.

Plus, one MAJOR reason to use a lathe, instead of just working on a drill press (http://www.instructables.com/id/Drill-Press-Lathe/) is so you CAN turn off-center, or non-round stock.


Have to agree with the author though, that a jacobs chuck for the tailstock is a wonderful addition to any lathe, regardless of size.

[Roninofthewest]

I'm impressed. Using nuts and bolts for the cross slide and compound rest was a very good idea especially on somthing this size. But how accurate is it? Have you thought of adding a digital readout using an old caliper maybe?

[Random_Canadian]

It is not as accurate as I would like. There is some play due to the coarse threads. This part does need some work to get tight tolerances.

[Random_Canadian]

Due to editing issues I will be adding updates to the the comments section.

I have added a brazing the 3-Jaw chuck video.

Please check out the link:

http://youtu.be/xz_PDPmp-ww

[jbradley2]

I so love this! I have made lesser gadgets with Sewing Machine motors, I want to go up and down with this project, up with a sewing machine motor, to make tough high torque projects like gun barrels, and down, with a small high speed motor to make delicate watch and mechanical releases or triggers.

The tool holder and some gear making ability could be deduced from the Gingery Workshop series of books from Lindsay Publishing!

I splurged just short of $300 for the Harbor Freight 7X10 lathe so I could make brass adapters to mate motor shafts, to tool pieces to make semi permanent grinders, and such, this would be such a better option. and a feature to make a sub micro key duplicator for quick 12 volt key duplications. well there went my sleep for the next week!

[bschroeder]

Would a foot pedal from a sewing machine have worked for the speed controller?