3D Printed Mini Lathe

11/12/2024 Update - I have added two files:
Toolpost Base - Brass Leadscrew Nut.stl - This allows you to use any 8mm leadscrew - specifically I am now using a leadscrew with a finer pitch and reverse thread: https://www.aliexpress.com/item/1005007779721345.html?spm=a2g0o.order_list.order_list_main.116.36561802dtdVet
Slidey Slides - Extended - Brass Leadscrew Nut.stl - Same as above, and this also extends the cross slide a little for easier tool access to the work piece.

This is my DIY 3D printed Mini Lathe. It started off as a project to use some parts that I had laying around which has influenced some design choices.

I would suggest printing all parts as thick as you can justify because you want everything to be as rigid as possible.
On many parts I used 7x walls of 0.5mm Thick and 20% infill.

Two Headstock Options:
Headstock-Solid.stl - This one is straight foward, print it and use it.
Headstock-Hollow.stl - This has been designed so you can fill it with cement, or resin and fillter material to add weight and rigidity.

Toolpost:
The top of the toolpost I am using has been partially fabricated out of 6mm steel plate which I tapped holes into. I have included "Toolpost Middle Section - For Steel Plates.stl" if you wish to do the same.
The other option is "Printed toolpost top.stl" which can be used if you can't fabricate the steel plates. I have designed it for M4 heat inserts. I would recomend this to be printed solid and make sure you have good layer adhesion. I have not tested this part, so I can't confirm how well it will work.

The motor mount I used was hand cut from 6mm steel. It's not pretty but it works. Hopefully most people can work out a motor mounting solution to fit the motor they choose.

BOM:
2x MGN15 rails 274mm long - Cut to size with angle grinder.
2x MGN15C blocks
2x MGN12 rails 162mm long - Cut to size with angle grinder.
2x MGN12H blocks
1x 20100 Extrusion 400mm long.
1x 2060 Extrusion 255mm long. - This was custom cut. You should be able to easily make this project work with any length extrusions though.

You do need a way to connect the two aluminium extrusions together. I used a 3mm thick 40mm wide aluminium plate and drilled holes in it.

Headstock:
SANOU K01-63 63mm Lathe Mini Chuck 3 Jaws:
https://www.aliexpress.com/item/1005002536342730.html?spm=a2g0o.order_list.order_list_main.138.4d52180258Rz1L
Tapered Roller Bearings 15x35x11mm:
https://www.aliexpress.com/item/1005007107128490.html?spm=a2g0o.order_list.order_list_main.144.4d52180258Rz1L
Hollow M14x1mm M14 Thread Spindle Shaft:
https://www.aliexpress.com/item/1005003767911053.html?spm=a2g0o.order_list.order_list_main.132.4d52180258Rz1L
15mm ID Lock Collar (may not be required if your pulley can hold the shaft in place):
https://www.aliexpress.com/item/1005002120340611.html?spm=a2g0o.order_list.order_list_main.120.4d52180258Rz1L
6x M5 bolts and T nuts to bolt the headstock to the 20100 extrusion.
2x M4 heat inserts - These holes can be used for the motor mount.

2x Leadscrews which are standard 2mm pitch 8mm diameter leadscrews that you find on 3D printers. You'll want one about 250mm long, and the other about 300mm.

4x thrust bearings, 8x19x7mm:
https://www.aliexpress.com/item/32899864102.html?spm=a2g0o.order_list.order_list_main.49.3cfa1802jB876U

8mm bore lock collars to push against the thrust washers.

2x 608 (skateboard) bearings.

M3 heat inserts.
M4 heat inserts.
Various M3 nuts and bolts.
M3 T nuts for 2020 extrusion.
2x pulleys and belt. Originally I used GT2, then moved to a 1:1 ratio with HTD3M pulleys.

For the handles:
4x 625 bearings.
2x M5 bolts.
I used a M5 tap to made the threads in the handle.
I used an angle grinder to make flats on the leadscrews.

For the toolpost, I used a small section of threaded rod and a 19mm nut. I think it may be imperial, but it's close to M12. if you can find a M12 bolt with a 19mm head that should work.

The motor and controller I used is probably overkill, but it's nice knowing that it's not a bottleneck. You could use a much cheaper brushed motor if you wanted to.
Motor Controller: https://www.omc-stepperonline.com/digital-brushless-dc-motor-driver-12v-48vdc-max-15-0a-400w-bld-510b
Motor: https://www.omc-stepperonline.com/48v-3000rpm-0-6nm-188w-5-40a-57x57x116mm-brushless-dc-motor-57bsd116-48-01

I think that's about it. Let me know if you think I have missed anything.