Teeth marks after feeder, normal? Also Feeder click.

[axislab 8]

Are the gear marks in filament generally this prominent, after passing through the feeder?

I have the tension set nearly to the lightest (top). Clicks badly if I go lower.

I do still get feeder slip/clicks about every 30 seconds as well.

Pla. I have ranged temps from 200 up to 225 with no difference, speeds from 40-60mms, and filament is measuring at 2.89mm.

 

[donmilne 2]

Yes, it's normal for the impressions to be prominent, though I can't really tell from the picture if those are especially deep. The filament itself looks mishapen, but that might just be a camera illusion.

I find that the depth of the impression is my main guide as to whether my tension is right. Impressions too light? The drive wheel might slip or grind. Impressions too deep? I might get skipping or stalling. If it looks like the knurled wheel has a good enough (but not too much) grip, then I should get reliable feeding. Basically I'm looked for the knurling and the impressions to mesh like gears.

The feeder clicking makes it possible that the tension is too high, and the filament is having trouble even making it through the feeder. Ditto the fact that temperature makes no differences (obviously that can't help the feeder end).

Incidentally, I suggest you switch to Robert's feeder. Among many other advantages it's a lot easier to tune the tension.

 

[fluxline 0]

a great http://www.extrudable.me/2013/04/18/exploring-extrusion-variability-and-limits/ by illuminarti discussing extrusion and under extrusion, one of the indicators to look for are the teeth marks in the filament. a great read.

 

[axislab 8]

Thanks for the link. Great guide.

Turning the feeder down to the lowest setting, does seem to eliminate the clicks. But of course I know that is just masking the real issue, and not the ideal solution.

Thanks Don for pointing me too the Roberts Feeder. After searching for more about it, and seeing how many people have gone to it, It is going on the list for sure.

I'm new to the forum, so there is a lot to study up on, but one thing is for sure, Ultimaker makes some amazing and beautiful machines.

 

[anon4321 16]

I assume that you have a UM2. I don't so take my advice with a grain of salt...

I believe one problem people have with the UM2 feeder is the motor heats up and transfers the heat into the knurled driver. This heat softens the filament.

So if I were you, find the minimum pressure and then add a little so you get good traction. Then remove the filament and let the printer cool (overnight) and then swap in new filament. If the first part of the filament has less sever indentations and the indentations get worse after printing for a while check how warm the knurled driver is. If it's warm, you can try reducing the motor's current to the point you miss steps (be sure to check retraction) and then increase it slightly. The stepper should run cooler and so should the driver and filament.

 

[gr5 2,173]

Clicks badly if I go lower.

 

That's bad. Better to click than have the filament slip.

There is a test you can run to see if something is wrong with your printer. Make sure the feeder is tight enough so that it's making good impressions in the filament and sometimes clicks backwards. Then at 230C print this test cylinder:

http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/

Also realize that the printer can barely print at 10mm^3/sec at 230C. At lower temps it needs to print much slower. In fact I recommend printing at half the value of the dark blue line in this graph - the dark blue line is the absolute limit:

http://umforum.ultimaker.com/index.php?/topic/4127-um2-extrusion-rates-revisited/

If you can't print above say 7mm^/sec on the cylinder at 230C then it's time to figure out what is wrong with your printer. But 8 to 10mm^3/sec failures I consider "normal".

 

[axislab 8]

Okay, here's what I got with that file, at 230. PLA

Clicking started right after 4mm^3/sec. And when I say "clicking", I guess that's the same as what is called slipping. The feeder skips back on the material.

This is some older material. I just received a brand new spool of Colorfabb, I'm going to do a run of that and see if there is any improvement.

 

[axislab 8]

Still running, But I think it's clear I found the answer to my problems. Bad filament.

With new material it is a world better.

This is actually somewhat disappointing, these Ultimakers are full time eNABLE machines. They are both personal, and classroom used, for making hands and education.

I was graciously donated 12 spools of older filament, to get started. Sadly I don't think the material will work.

The bright side, is with nicer filament, the machines are going to run GREAT!!

time to start working on building a filament collection.

Thanks guys for helping me through this.

Finished

 

[donmilne 2]

When you say "old filament", do you mean that you were running towards the end of the spool? If yes then it could have been the high curvature of the filament caused binding and friction, rather than the filament per se. It's a problem.

The clicking btw is caused by the stepper motor not having enough oomph to reach the next step, so on the step after that it jumps to the nearest stable state - hence the audible click. It tells you for certain that there's a big buildup of pressure and/or friction somewhere.

Now that you have a working printer, I'd get Robert's feeder printed, even if only to be held in reserve!

 

[randyinla 14]

You'll want to print the feeder out of PLA so that if any particles rub off and on to the filament, it'll be melted in the hotend. ABS melts at a higher temp, so any of that would get clogged while printing something out of PLA which has a lower melting temp. Read through the description and comments for the feeder. I cut off 1/4" of my bowden tube and pushed it into the bottom of the feeder so my filament is never in contact with the PLA.

And while you're at it, print up Robert's Low Friction UM2 Spoolholder. It incorporates bearings for an ultra smooth spin (watch the video)

https://youmagine.com/designs/low-friction-um2-spoolholder