Unimat SL modification to improve control of milling depth

[Barkersoldbean]

I am a hobby user of a unimat sl and struggled to control the depth of cut when milling - due to the crude and coarse action of the splined handle that moves the milling head up and down.

I’ve seen some rather elaborate add on devices to better control the milling depth; but these seemed to junk what is a good basic mechanism for moving the milling head up and down - it’s just too coarse.

I decided to try and retain the existing mechanism but just add a method of finer control - via a 1:30 worm drive.

Essentially, the existing splined shaft is rotated indirectly via a worm drive assembly bolted to the milling head using the existing M6 bolt holes.

It was all made on the unimat sl, works really well and cost around £10 to make - you just need to source the worm drive gears from eBay.

If anyone’s interested in exact drawings and a work plan - I can try and pull it together.