Tuesday, 8 March 2016

CNC spindle upgrade

We've had our old desktop CNC collecting dust for quite a while now.
It's a beast of a machine (for a little desktop thing) and really sturdy, built from lumps of aluminium bar all bolted together.

But it does really get the use it deserves.
Partly because it's really slow.
And partly because it's quite noisy.
But mostly it's been because the dremel clone we were using for routing was knackered; and Dremels in general have too much run out to be used for anything other than simple, coarse shape carving.

So while we're waiting for a few controller boards to arrive, to upgrade the entire drive system to GRBL (it uses a nasty parallel interface and Mach3 as the controlling software) we went and ordered - and have since now fitted - a new spindle.

We took the old mounting plate off the z-axis - one of the nice things about the whole frame being bolted together is that it makes working on just parts of it really easy - and marked it out for drilling.

It was very tempting to just attack the aluminium with a household drill. But the new holes for the new spindle mount were going to be right on the very edges of the aluminium block, so it was important  to make the hoes truly vertical. This, of course, meant a trip to BuildBrighton hackspace to use the pillar drill.

The holes were drilled with a 5mm bit and tapped out with a 6mm tap-n-die set. From the photo it's clear how very near the edges of the block we had to drill.

An hours bus-ride later (after hopping on a wrong bus and ending up in the bowels of Brighton's suburbia) and the new CNC spindle was ready for fitting to the frame.

The controller board requires a dedicated 24V supply so we're going to have to cobble something together from an old PC supply if possible; otherwise it'll be another week or so delay while we wait for one of those to arrive too!