Extrusion calibration

[Jules]

At any point did the hot end get turned or twisted in the clamp? If the heater block is not perpendicular to the x-axis rail, you will sometimes see uneven extrusion between one side of the calibration cube and the other. (One wall will be significantly thinner than the others.)

[scampa123]

At any point did the hot end get turned or twisted in the clamp? If the heater block is not perpendicular to the x-axis rail, you will sometimes see uneven extrusion between one side of the calibration cube and the other. (One wall will be significantly thinner than the others.)

Not that I am aware of! I can't imagine it is loose...If it were moving around, wouldn't it mess up the prints even more?

[Jules]

No, not that it's loose, just that it turned. The heater block needs to be completely perpendicular to the rail before you tighten the clamp. (I'll update this with a picture in a minute.)

Like this:

[sthone]

I never really understood that theory... If the barrel is round, the nozzle is round(ish) and the block is machined correctly it really shouldn't matter which direction it's mounted. but hey if it fixes the problem...

[Jules]

I never really understood that theory... If the barrel is round, the nozzle is round(ish) and the block is machined correctly it really shouldn't matter which direction it's mounted. but hey if it fixes the problem...

I didn't either, but I've experienced it, and sure enough, turning the block back around fixed it. No idea why it happens.

[zemlin]

I never really understood that theory... If the barrel is round, the nozzle is round(ish) and the block is machined correctly it really shouldn't matter which direction it's mounted. but hey if it fixes the problem...

I didn't either, but I've experienced it, and sure enough, turning the block back around fixed it. No idea why it happens.

Hmmm . my RevE came from Makergear with the hot end rotated 90 degrees to that - the leads coming out of the right side. Haven't touched it.

[Jules]

Hmmm . my RevE came from Makergear with the hot end rotated 90 degrees to that - the leads coming out of the right side. Haven't touched it.

Not something to worry about really, unless absolute dimensional accuracy is necessary for your print, or you see a problem.

(And it might not be the same thing for the Rev. E machines...they're a different animal, and untested so far for this particular issue.)

[NF6X]

I haven't gotten the hang of extrusion calibration yet. I started off with a single-walled test square, adjusting the extrusion multiplier for 0.4mm wall thickness. I carefully avoided the bottom layer while measuring with an excellent digital micrometer, so I wouldn't be throwing off my measurements with any bottom layer smoosh. I ended up with a multiplier around 0.83-0.85, resulting in very nice 0.40mm wall thickness, but insufficient top layer fill and poor adhesion between side walls and top/bottom layers. When I tried printing something for work which required support under large horizontal flat bottom surfaces, the supported surfaces ended up stringy like mistreated bamboo. I've made a mental note to experiment with deliberately seeking that result later to simulate wood grain.

This evening, I have been experimenting with adjusting the extrusion multiplier and temperature for good top later fill of a solid calibration square (with 20% infill so far). I still have some small gaps with extrusion up at 0.94. I started at the 200C extruder temp that I had been using, then moved up to 210C to see if that might help adjacent extrusion adhesion a bit.

Tonight's experiments have been with some white PLA from esun which happened to be on the machine, but I think I'l switch back to the original black PLA that came with the machine until I become competent at slicer calibration.

I expect to experiment a bunch more before I really know what I'm doing, but I'm a bit confused that I don't seem to be getting correct wall thickness and proper top-layer fill near the same extrusion multiplier.

I haven't put on my dual extruder upgrade yet. I don't think I need that extra complication until I learn how to dial in everything very well with a single extruder.

[ednisley]

very nice 0.40mm wall thickness

Dumb question that still trips me up occasionally: is the slicer producing 0.40 mm threads?

If it thinks it should be producing 0.45 mm threads (perhaps because that's the "automatic width" setting), then forcing a 0.40 mm width with a low extrusion multipler just starves the output. Setting the multiplier to produce a measured 0.45 mm to match the expected width should get you pretty close to perfection.

Slic3r puts all its settings as a block of comments at the bottom of the G-Code file. Perhaps S3D does the same thing, so you can verify what it's actually doing or, at least, find out what it says it's actually doing.

There are also a gazillion infill settings, but if you haven't messed with those, they should be pretty close to All Good.

[Jules]

....When I tried printing something for work which required support under large horizontal flat bottom surfaces, the supported surfaces ended up stringy like mistreated bamboo. I've made a mental note to experiment with deliberately seeking that result later to simulate wood grain.

This sounds interesting....would be neat to see what you come up with.

This evening, I have been experimenting with adjusting the extrusion multiplier and temperature for good top later fill of a solid calibration square (with 20% infill so far). I still have some small gaps with extrusion up at 0.94. I started at the 200C extruder temp that I had been using, then moved up to 210C to see if that might help adjacent extrusion adhesion a bit.

Tonight's experiments have been with some white PLA from esun which happened to be on the machine, but I think I'l switch back to the original black PLA that came with the machine until I become competent at slicer calibration.

I expect to experiment a bunch more before I really know what I'm doing, but I'm a bit confused that I don't seem to be getting correct wall thickness and proper top-layer fill near the same extrusion multiplier.

I haven't had any success with modifying the multiplier either, ever since the newer versions of S3D came out, (it worked better with version 2.2 and prior). And when you get to working with the dual, you will have to have the extrusion multiplier and filament diameter set to the same number for both filaments anyway. Now I just leave the default filament diameter of 1.75 mm and the EM of 0.90, and it works fine.

The one thing I've found that does consistently work for getting good fill with the Rev.E machines is gap adjustment and fine tuning the gap using the Z-Adjust app with the G-Code modifications that the guys came up with here:

Z-Adjust Application: viewtopic.php?f=3&t=3666&p=25703#p25703

And you might want to up the infill percentage a bit - 20% is on the low side. (Better top surface with about 40%+)

I haven't put on my dual extruder upgrade yet. I don't think I need that extra complication until I learn how to dial in everything very well with a single extruder.

Smart!