1 Topic by BotBot

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Topic: Extruder is grinding filament into dust

So I was printing a couple of pieces yesterday and I come back to find that only the first two layers printed. It turns out the hobbed nut had ground a chunk out of the filament and didn't have any purchase. I have cleaned the nut three times and restarted the print every time, but the same thing keeps happening.

If I remove the filament and clean the nut I can manually extrude at the proper width, so I don't think there's a clog or anything. Maybe it's partially clogged if that's a thing. I recently changed to a clear filament from natural ABS, so I'm going to try running the natural again tomorrow to see if that makes a difference. I'll post pictures tomorrow if the filament change doesn't help.

Any suggestions would be appreciated.

2 Reply by lawsy

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Re: Extruder is grinding filament into dust

Sometimes this happens to me if the extruder temperature is not quite right. If it is too low, too much force is required to push the filament through the hot end and it strips instead. I've had to up the temp on my new hot end a few times to get the balance right.

What temp are you printing at?

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3 Reply by BotBot

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Re: Extruder is grinding filament into dust

I dropped it down from 195 for the natural to 185 for this filament because it expands so much at higher temps. I suppose I should bump it back up and just reduce the flow rate a lot more. I'll let you know how it goes.

4 Reply by BotBot

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Re: Extruder is grinding filament into dust

Here's a video of the extruder skipping.

It seem sthis person had a similar issue. http://www.soliforum.com/topic/582/extruder-skipping/ I'm going to try clearing it out with some wire and if that doesn't help I'll disassemble it and clean it.

5 Reply by BotBot

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Re: Extruder is grinding filament into dust

So I tried the wire trick with some 28ga wire. I pulled out a very tiny bit of black stuff with it. Printer seems to be running fine now.

6 Reply by IanJohnson

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Re: Extruder is grinding filament into dust

Is the clear filament clean, no contamination evident in it?  Where did you get it?  My Repraper clear has black bits in it, so I pull out only as much as I think I will need for a print so I can be sure none of them will be fed into my nozzle.

7 Reply by BotBot

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Re: Extruder is grinding filament into dust

I got it from Zen Toolworks on Amazon. It doesn't appear to have anything in it. No bubbles either. I think the problem was that I was letting the extruder idle at 100C while I let the bed warm up. It probably burned a bit of filament while waiting.

One interesting thing about this filament that I think is different from the ones you tested. Its clearness appears to be affected by layer height. When I print at .3 it looks really clear, I can even read faint text through it, but when I print at .1 it gets really cloudy. That's also one of the reasons I was using a lower temp with this filament, but it didn't seem to make any difference. I haven't found any reviews of this filament anywhere, so I'll post some pictures and comments in a thread once the semester is over and I have some free time.

8 Reply by HelmutK (edited by HelmutK 2012-12-03 20:29:51)

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Re: Extruder is grinding filament into dust

I picked up a spool of the transparent abs from Zen Toolworks also. I also have had no issues with it. Except for me it does not seem that clear after printing. I am printing at 200C but will be trying 195C next. For me it seems to extrude as good as any other spool of abs I have. Have seen one or two small flecks in the print but this seems to only happen towards the beginning of the print. I have not actually seen any black flecks in the abs off the spool. I do not let my extruder set at full temp more than 10 minutes.