Monday, 27 June 2016

Printing some actual things, and some small dowels

Printing things! Did a test run of the adapter part of a lens extension piece ( and it fit just nicely. Now I can print the whole thing.

Decided to try out Cura for slicing. A simple test cube looked mostly good, except one corner ended up sort of sliced off. And then the piece came loose when doing the top layers, due to forgetting the hair spray. Cura doesn't allow higher temperature at the first layers, and is more aggressive with the fan.

Repeating with hair spray worked, but there was no noticable difference. I don't feel like throwing $150 at Simplify3D right yet.

Next attempt: Full height macro extension piece. First one clogged up quickly, but after a quick atomic, it went nicely. Suggests that my Z offset and/or initial layer height is too high.

The difference in magnification is noticable (note these are handheld shots, so not super sharp):

Test piece at maximum magnification with EF-S 60mm f/2.8
Same test piece, same lens, with extension tube
Over several prints, some of which jammed early on, I have come to the conclusion that the right Z height is critical. I need the nozzle low enough that I get proper adhesion, but high enough that the filament can squeeze out without too much backpressure, or the resulting grinding of filament will cause the hobbed bolt to slip more and more over time.

Initial layer squeezed out so tight it turns white
I printed a sample hinge for the piano, but smaller than necessary so it didn't hinge well.

I printed a battery dispenser for tracked charged/discharged Eneloops. It came loose from the bed while printing, and when moving across a slightly lifted layer would make a chack-chack-chack sound. Now I know what that is, at least, but the lifting is problematic. In the end, it caused a jam, though the piece ended up OK:

As part of printing a dish rag holder, I experimented with making simple dowels. A good test, for it takes only 10 minutes to print a short pair, and it's obvious whether it works.

0.2mm layer height, outer walls first: 5.80-6.05 mm male/5.30-5.40 female
0.2mm layer height, not outer walls first: 5.85-60.5 mm male/5.05-5.20 female
0.15mm layer height, outer walls first: 5.60 - 5.80 mm male/5.25-5.35 female
0.1mm layer height, outer walls first: 5.65 - 5.90 mm male/5.25-5.45 female

Trying with perimeter adjustments of 80% exterior/90% interior. Also slowly moved the Z offset up to +0.1mm, since the first layer still got squeezed enough to be white, which I take as a bad sign.

0.1mm layer height, outer walls first, 80%/90% ext/int: 5.85 - 6.10 mm male/4.75-5.00 female

This also made the sides of both pieces look funny, with extra extrusion on the top part of the female piece, and some gappiness on the male piece. Probably not a good adjustment to make. Going back to default on those, and 0.15 mm layer height, but then (just on a lark) with 0.9 extrusion multiplier.

0.15mm layer height, outer walls first, .9 extr. mult.: 5.45 - 5.55 mm male/5.42-5.47 female

That's an incredible improvement! These actually fit together with just a bit of squeezing. And they look good, too, except for rather large flanges at the bottoms:


  1. The traditional way to change temps per layer is described at

    If you have a model (and the speed/temp/thickness settings) I have access to s3d and can slice something for you as a test.

  2. Ah, I must be blind, then.

    For s3d I would want to be able to do some running tests - Thomas Riedl had enough problems that he ended up getting a refund (for a different printer). It looks like some people have done s3d+mendel90, but I'm skittish.