This post is about more Reprap tuning, so if you don’t find stuff like this interesting, feel free to tune in next week. The first test turned out like this:
Layer height: 0.254
First layer height: 0.35
Perimeter speed: 30
First layer temp: 190
Layer temp: 185
Dimensionally the part is close, the sides are within .1mm but the height is about 10.3, which has me worried I have something wrong in the firmware since I swapped out the z-rods. The thing I was trying to address are “blobs” on the corners of the Tantillus parts I printed last night. Unfortunately (?) when I printed this part with the same settings I don’t get those blobs. For now I’m continue to test to get the dimensions closer, and to address one distortion I’m seeing where the z axis changes layers. Second Test
Layer height: 0.25
First layer height: 0.25
This didn’t seem to improve the dimensional accuracy, and about 1⁄3 the way through the print left the table, so we should re-test with an initial height of .35 to see if the part sticks again. Third Test
- First layer height: 0.35
This didn’t appear to have any effect either, but at least the part stayed on the table. Fourth Test
- All layer temps: 190
I tried making the temp consistent across layers to see if I could get the first layer to stop shrinking relative to the others. Visually, the part looked a little better but it didn’t make a difference in what I’m testing so I’m taking the temp back down to 185. Fifth Test
First layer temp: 190
Other layer temp: 185
Retract: 0
This did wonders for the distortion when the z axis is lifted, but I’m afraid that it’s going to cause stringing so adding back .3mm of retract (vs the original 1mm). Sixth Test
- Retract: .3
This looked alright but since the cube I’m testing with won’t tell me much about stringing at this point I re-printed one of the real parts I printed last night for comparison. Seventh Test
- Extrusion multiplier:
Lowering the extrusion multipler is a way to determine the correct e-steps you need to make sure you’re feeding the right amount of plastic in to get the right amount out; too much and you get blobs, so i’m testing reducing this.