Part 0004 finished

I made 2 more of these yesterday afternoon and I made 3 more of them this morning, so that is the 6 required.
With my method of clamping on to a sacrificial piece of hardwood, there are inaccuracies in thickness of the parts. If I clamp tighter, I get a thicker piece. Most of these pieces are between 9.96mm and 10.02 at the edges and about 9.85 to 9.95 near the middle ( depending which part you measure ), because of the way the piece is bending when clamped. But one part is about 9.88 all over, where I didn't clamp it so hard ( to try to reduce bending ). I could improve this, by using some aluminium to act as the sub-table, but this would make everything more expensive. I think these are meant to be fairly low cost parts. I will try clamping more gently for the facing operation, but adding 0.1mm to the programmed depth.

Part 0004

I made Part 0004 correct, first time. There are 6 in total wanted of these. I got the chamfer to within 0.1mm of what I wanted, I think; it's hard to measure the chamfer. The subsequent copies should be more relaxing to make. There are no tags on this part. I cut the outside profile in two separate operations, so I could remove two of my four clamps and replace them to get to every part of the profile. I put my fingers on the part as it was being cut to catch the piece of scrap that falls off and to damp vibrations.

Part 0003

I made Part 0003 correct, first time. I was able to re-use some of the operations from Part 0002.

This video shows the rough profile pass for the outside shape, done in two steps of 5mm.

Part 0002 finished

I did Part 0002 again with no mistakes.
The chamfer is about 0.2mm under size. I don't think this will be a problem.

Part 0002 again

Only one mistake, this time. The chamfer was too big. I worked out what I did wrong. I wanted to offset the path 1mm from the part, so I told the software it was using a 1mm slot drill. I should have told it it was a 2mm slot drill. The chamfer is 3.8mm instead of 3mm. I left on 0.2mm for safety, but it was not enough.

Part 0002

I am making another part using HeeksCNC 0.13.0 and my Sieg KX1.
I made several mistakes and the part is scrap, but I didn't break any tools.
Mistake 1: The clamps were not far enough from the toolpath. I loosened one clamp and moved it and retightened it during cutting. This let the part lift up a little and I cut too deep. I should have pressed STOP, then moved the clamp, then restarted the operation.
Mistake 2: I zeroed the Z of the chamfer tool assuming it comes to a sharp point, but it has a small flat. So the chamfer was cut too big.
Mistake 3: I saw 5 holes and assumed they were all the same size, but some of them were smaller.
I will try again with no mistakes.

Part 0001

I have made the easiest of the Delrin parts. First I sawed out a piece.
Then I clamped a piece of wood and pocketed an area big enough for the Delrin.
I clamped it down and pocketed a rectangle at z10 with my 6mm slot drill.
Then I changed tool to the 3mm slot drill and pocketed and profiled the holes.
Then I profiled around the outside shape with the 6mm slot drill. The first operation used two depths of cut and left 0.1mm around the outside, climb milling. The second op used one depth of cut and took off the 0.1mm.
I used two tags.
I was pleased with the accuracy. I sawed out the part and sanded off the tags.
All done with HeeksCNC software ( www.heeks.net ). Although I did find some problems and improvements which I had to make to the software before I could get the toolpath.