STLCutter 2 - Aftermath

Because of the little time I had to spend on this part of the build, I skipped a few steps that I would like to do later on:

1. Fit limit switches
2. Get proper brackets made for the ballscrews
3. There's still some bolts left to insert
4. The PIC can be used to control the CNC machine
5. The MDF needs to be milled to be level by using the machine itself

There were also some improvements that we should make:

1. It does need a second ballscrew (and motor) for the X-axis if it's accelerating or decelerating a lot. If you get it to resonate (which happens when using EMC2's default movement distance for testing an axis), then the far end really does move. This was expected, but the extent wasn't known until tested.
2. The Y-axis ballscrew should be moved between the two bars - again, it only really happens during rapid acceleration/deceleration.
3. The Z-axis carriage does have a slight amount of movement - it's to do the 5mm plate flexing a little. For all of these, the accuracy we have is good enough for our needs, but we'll rework it later on to give us more capabilities.
4. I'll replace the Y-axis motor coupling with one the right size, to prevent slippage.
5. We need to work out a way of holding the blocks.
6. I want to change the algorithm to do more of an outline, rather than an absolute depth position. This should make it much smoother.
7. I may look at using a proper spindle mechanism - the arms for the router could interfere with the foam if I use a shorter tool. Although I could use a collet extension.