11.3 Test prints that test something
Before the real print I wanted test prints. Claude's first draft sliced the clamp and the swivel, to test the shelf fit and the stops as well. That was 1 h 53 min and 45 g, and I said it was too much. The limit was under 20 minutes each.
Then I asked the question that reset them: what are the tests for? We have the VESA mount points and we know the shelf thickness. I'd test the thread of the bolts. Print a part with a thread and a hole, and see if the bolts tighten properly.
So the tests confirm only what the CAD can't: how printed PLA takes the kit's nuts and bolts. There are three blocks, each cut from a real part with a box intersected with it, so each keeps the part's own holes, pockets and print direction:
- The spine round a joint nut slot (M6 × 10).
- The post's seat round the held nut (M6 × 20 on a washer).
- The seat round the stop's M3 pilot (M3 × 6).
The real knob is a test as well. The three blocks slice to 18 min 37 s and the knob to 19 min 3 s. I printed them as one job: 31 min 1 s and 9.47 g.
Results
The spine block and the held-nut block worked, and so did the knob. The M3 × 6 was too tight in its 2.5 mm pilot, so the pilot went to 2.7 mm.
I also measured the kit's M6 nut: 9.85 mm across the flats and 4.93 mm thick. The standard's maximum is 10 and 5.2. The jaw's nut slot had been cut at 5.2 with no clearance, so it got the tested 0.15 mm a side.
One note on print times. The slicer's estimate counts the A1's timelapse move on every layer, about 4 s a layer, which the printer skips with timelapse off. Slicing a one-part plate "by object" leaves it out.
The knob passed its test. It tested the fit, but not the turning force. That comes back in 11.5.