Regular readers may know that I've not always got on well with my little mill.

In particular I seemed to keep stripping the gears – to the point where I was ordering them in quantities (admittedly small quantities, but..).

The general concensus (and certainly mine) was that this was a combination of brutality and general cackhandedness.

But it wasn't entirely me! I noticed quite early on that the gears were wearing unevenly, particularly on the low range gear. When I measured new gears I found them to be around 0.25 mm out of round. That's both the ones from Clarke and the ones from ARC. Oh – and before I put them in the mill not after.

But that's not the main thing. I always thought they weren't meshing well but it's pretty hard to prove that given that they assembly is unsupported when the top plate is taken off for examination.

One day, though I thought I'd find out why there was a slot in the support for the motor box. there are a couple of all key bolts under the motor box. You can loosen these off and twist the motor box. This appears to have the effect of bringing the gears closer or further into mesh.

This terrible photo is the underneath of the motor box showing the bolts

And this slightly better one shows what it looks inside

I tightened this up as an experiment and thought I would see how it went. If it went well, then I would take a photo next time the gears broke and report it as a useful adjustment.

That was about 6 months ago. The gears still haven't broken and I've done really quite a lot of milling!

In fact, what goes is either the overload trip or the key pops out of the keyway on the motor.

Of course this isn't definitive proof, but if you have a micro mill which goes through gears, this might be well worth a try!

Iain

It may be how well it's set up in the factory.

I've gone through 3 or 4 fuses in 2 years. but more gears until recently.

Iain