A work of art from http://www.lathes.co.uk/fonly/
I will move the holding block forward to reduce the overhang of the chuck shank.

It would be difficult to improve on the simplicity of the 'fonly lathe, so I won't really try.
Here I will present some thoughts on improving its versatility, and maybe making even cheaper.

This is the original plan for the lathe: fonly page1  fonly page2
If you only need a simple lathe for wood only, take a look at this PDF file for a Dremel wood lathe.

If you already have a Dremel type tool I would start with reducing the bearing play.
How to tighten up a second hand Dremel
Dremel bearing
This may apply to other brands as well. On my model 400, the play was in the bearings themselves. I left it alone.
The screws are Torx T15 size.

Holding the work piece This represents the greatest challenge for a tool meant 1/8" maximum capacity.

This is the collet nut for the 1/8" collet that came with the tool. Smaller collets are available.
Dremel collet nut
I found these: That I can use to make a face plate and a sanding disk. Still not what I would consider cheap, but less than buying a collet set for the nut.

1/4" Dremel chuck
I turned the diameter of a somewhat worn collet nut down by running the Dremel at lowest speed and held a file against it. A Jacobs 1/4" chuck I salvaged from a dead drill motor was drilled out to 13/32 on drill press. A new 1/8" drill bit was placed in a collet and the collet nut tightened. The inside of the chuck, and the outside of the collet nut were cleaned with acetone, J-B Weld was spread on the collet chuck. The drill chuck was slid over the nut and gently tightened around the 1/8 bit. I checked for run-out but running the Dremel at lowest speed. Watch your eyes! It slung a little cement in my face. I am pleased with the results. The whole project took maybe a half hour.
Finished 1/4" chuck for Dremel 400
If you are not pleased with the alignment, you can heat the chuck with a propane torch, remove the collet nut and start over.


Larger work can be held between centers and driven by a dog. I have two thoughts here. (1) would be to sacrifice another collet chuck and glue it inside a hardwood ply disk to make a face plate, or (2) make sort of a second dog that clamps to a collet nut that has two hardwood dowels to drive a straight dog. The center can still fit inside the collet either way. A center can be made but filing/grinding down an old 1/8" grinding wheel shank. The standard angle is 60°.

A method used on jewelers lathes to hold odd shaped parts is a wax chuck, which is simply a shallow cup that hold the part with a very hard wax available from lapidary supply houses. The chuck is heated and the part pressed into the molten wax. When removed later, the hard wax can be easily chipped away. Black dopping wax  holds best and melts at 165°F.

Filing rest and index plate
In all the years I have been machining I always wanted a filing rest, but never got around to making one. I have some stainless steel tubing from the hobby store that is a good fit on 1/4" rod. This will be the rollers. Instead of a complicated method as above to adjust the height, it will be mounted on a door hinge with a single screw to raise and lower it.

Filing rest
What's it good for other than just finishing with a file? Well, lets say we want a precise square end on a round bar. On jewelers lathes, the chuck is indexed into place and held there with a pin. Since jewelers work with small items (obviously) filing makes more sense because the part can be made long before you could set up a small milling machine.
Jewelers index plate
The four sides would be filed for each individual position.  *gulp* that is an awful lot of holes to drill accurately, but I would most likely only need to index at 4, 6 and maybe 3. (4 is also used for 2, and 6 also used for 3, etc.) The holes could be color coded with a magic marker to avoid a lot of hole counting and confusion... say, red for 4, blue for 6, green for 3 etc..

On the only jewelers lathe I have ever used the index plate was large with concentric series of holes mounted at the rear of the spindle. A swing arm had a pin to insert into the selected hole. Of course it isn't possible to put an index plate at the rear of a Dremel powered DIY lathe, but one could be affixed to the front. Unlike the jewelers lathe, the index plate would attached to the frame and not the spindle. A pin in a dog would index the work.


Construction of my version