Thursday, 9 January 2014

CNC - First real cut

 Here's the first real run with the CNC with a diamond engraving bit in the dremel.

I put a grid of silicon door bumper pads (about 7mm dia) on the bed as way to stop the acrylic work-piece from sliding.  I also used a pair of moly magnets from an old server HDD, one stick to the underside with double sided foam tape.  These things have enormous amount of magnetic pull, and with the other one directly above it, it clamped the work-piece to the bed without risk of distorting it.  Works a treat!

I used CamBam to generate the g-code, but I reckon I had the feed rate too high.  The dremel bit seemed to twitch when it got to the end of each it was under too much side load.  This did cause the letters to have a small bump at the start/end point of each character.

This run was 1.0mm deep, 0.5mm each Z step, and 200mm/min feed rate.  I might be a bit ambitious with these settings :-)

It also doesn't help when the dremel collett seemed to swing the bit off-centre upwards of 0.25mm each way (a combined runout of 0.5mm).

The CNC router upgrade may be sooner that I had planned, but in its current state, a reasonably OK setup for learning with.

Next test..cutting a profile and drilling some holes.  If I don't update this for a while, it's most likely gone all horribly wrong...but that's just me being optimistic :-)


1 comment:

  1. Stress-testing your machine right off the bat is a good practice. That way, you'll also know how far you can take the device without damaging it. There's a massive market for people knowledgeable with CNC machines. If you get to learn more from them, you could take advantage of it. Keep us posted on your next projects!

    Deborah Williams @ Choice Career College