Difference In Printed Cubes

[desman]

PLA and ABS both print in good shape. Perhaps I should not have tried to use the Madesolid profile even though it is their material. It seems their way of doing things is a bit different and just adding to my confusion.

[desman]

It appears where things got out of kilter was not taking 1.1 x .9 which would have put me at .99. My initial calibrate square was in the .36 range.

[Tim]

My initial calibrate square was in the .36 range.

Huh. I wouldn't have expected that. It's like the stuff doesn't squash at all. Maybe that accounts for the poor layer bonding that some people have found using PET+?

Also see this thread:

viewtopic.php?f=11&t=1948&p=8995&hilit=MadeSolid#p8995

which has additional useful information about changes needed from the MadeSolid example profile.

[desman]

.36mm wall thickness not multiplier.

[Tim]

.36mm wall thickness not multiplier.

Yes, I understand that. Unless you have a 0.25mm nozzle, it means that the filament comes out of the 0.35mm diameter nozzle and deposits itself with nearly zero flattening, so that it still has (almost) the same diameter as it had coming out of the nozzle. The flattening is controlled by the amount being extruded vs. the height of the nozzle above the last build layer, so that the nozzle itself is flattening the filament by forcing it to squeeze between the nozzle and the build layer underneath. It's usually sort of difficult to keep the plastic from expanding outward, getting wider as it gets flattened, which is why the automatic setting for extrusion width is always a bit bigger than the nozzle diameter (e.g., 0.42mm for a 0.35mm nozzle). So I just found it surprising that the PET+ could maintain such a low width. Your result is actually similar to other PET+ profiles I have lying around, which have an extruder multiplier of 1.04. Those are Jim's profiles, I believe, and are for the E3D extruder. I always assumed that the high extruder multiplier was due to the E3D, but maybe it's just a property of the PET+.

[jimc]

i was still running a v3b when i made that profile and it worked fine for the spool that i was using. i never consider the multiplier to be a variable that can be moved from one persons printer or spool to another. that is something that needs to be set individually by every user. my filament dia setting could have been just 1 point off which required the multiplier to be raised. who knows. these days i find that if my dia is set right then almost every fialment runs a multiplier around .96-.98.

[desman]

Jim that is good to know and can simplify things quite a bit.

[Kulturfolger]

It depends on how tight you dial in the idler. On PLA you can let it grip very gentle but on the stiffer stuff it needs to tighten a littlebit more. The wear in also reduces the diameter of the drivegear. But this takes time.

[Tim]

It depends on how tight you dial in the idler.

Of course, you "dial in" the idler with a screwdriver. Personally, I don't spend much time worrying about how much pressure is put on the filament, and have never had any problem with filament feeds (except when something jams). On the other hand, I've been using PLA and PET almost exclusively, although my one print with PVA (very soft) was a total success, without making any changes to the tension on the drive. I'm getting some eSUN polycarb soon and will see how that goes.

Can it really make that much difference to the settings? I guess I can work that out with an "engineer's approximation". . .

If the drive gear is, say, 10mm diameter (engineer's approximation---use easy-to-calculate numbers), and you aren't digging into the filament at all, then a full turn of the gear is (assuming pi = 3, another useful engineer's approximation) 30mm of filament. If you're digging into the filament by a half mm, then you reduce that to effectively 9mm diameter and 27mm of filament. The difference is 3mm / 30mm, or 10%, which is the difference between an extruder multiplier of 0.9 and 1.0. So, yes, you're absolutely right.

Kind of annoying, though, that so much variability in the settings depends on something you can't measure. Makes me want to replace the machine screw tensioner with a vernier dial, so that I can get an exact value to plug in.

[CCVirginia]

What???
The pressure would change the shape of the filament but not the amount, so unless there is slippage it should not change the extruder multiplier.