Okay - after a fun Christmas Day (love my Kindle!) it was time to get serious about Motorama 2012. We have the week off this week, so looking forward to a getting a whole bunch of building done. As we're waiting for parts for the new 'bots, and didn't much fancy tackling the wiring on Unlettered Understrapper 2.5, we decided instead to spend some time working on the chassis for our other new beetleweight Versatile Villain 0.9. Hit Back after viewing an image.
Our mill vise can't handle the 8.75" chassis block, and given our problems working on the fairyweight chassis with it in the vise, we decided instead to try bolting it down to the cross-slide.
We elected to tackle the milling in three segments - middle, front, and back - with the front being to the right in the picture. There were a couple of spots where we weren't entirely sure about clearances of the bolts for the clamps, but we figured we'd give it a shot anyhow!
A quick shot of the CNC control system - Mach3 - running our G-code. There are a number of functions we still haven't figured out yet, but we appreciate the opportunity to practice. It was actually a bit daunting going straight for a one-off block we don't have spares for should something go wrong, but there's no time like the present!
Oops! We hadn't entirely positioned the block properly, because we hit the extend of the Y-axis. So we stopped the G-code program and repositioned the block. We were aligning the block with the edge of the cross-slide, which allowed us to keep 0 on the x-axis in the same place, and just had to recalibrate the Y-axis.
And we're off and running! We're going in three passes - 0.375", 0.75", and 1.125" deep. It's only UHMW and we could probably do more at a time, but we wanted to be a little careful.
Having completed the first pass in the middle section, we took a quick photo and reset for the next round.
Cool! The middle section is done, so it's time to adjust the clamps, and load up the G-code for the front third.
We've reset the clamps, and we're about to get the next section underway. We did take a sanity check to ensure that the spindle will keep clear of the clamps, and it does, barely - but "barely" is enough :-)
After some more 220V consumption we have two-thirds of the milling done. Time to readjust the clamps again for the final third.
Here's a gratuitous shot of the last section underway. You don't have to click on this one ;-)
And hey presto! We're done! Actually, we're not done because the original material was actually 1.5" thick and the 'bot is only 1.25" tall, so we'll need to load back up tomorrow and take the base down a bit. You'll also notice that the top plates don't quite actually fit, as we were a little off in calculating the curves, so we'll have to touch them up a bit too.
We also milled slots for the weapon arm in the front and back walls. We'll need to run a razor blade over the base to clean up the 'hairy UHMW' from cutting in the 'wrong' direction. CNC'd material always end up looking nifty.