SoliForum - 3D Printing Community — Filament Bunching Inside Acrylic

Re: Filament Bunching Inside Acrylic

2013-05-26T01:33:13Z

If you are using retraction settings in slic3r you may want to make them smaller. You could be retracting softened plastic and when it tries to re-extrude bunches up. Especially if you are getting through part of the print your retraction setting may be right on the edge of that happening. And as said before misalignment will also worsen the issue.

Re: Filament Bunching Inside Acrylic

2013-05-26T01:19:38Z

I've never had a single problem with Makerbot's plastic - it was just too expensive at the rate I go through it, and they were often out of stock for some popular colors.

I've had no problems with my SD3, but my SD2 did take a long time to get going as it initially had poor continuity for the extruder heater, and there were problems caused by antivirus software that kept causing prints to hang (that took weeks to figure out!). Hopefully, yours gets solved soon.

Re: Filament Bunching Inside Acrylic

2013-05-25T23:22:22Z

Yes, it is ABS. I know it is sacrilegious, but I live in NY and work right down the street from the Makerbot store. They have a big selection and I don't have to wait for shipping. I can't imagine that their quality control is poor, but if someone has had a bad experience with this brand with the SD3, please let me know. As for the room I'm printing in, it's an office with a few computers in it so I can't imagine it's too dirty.

I was going to put an enclosure on my SD3, but I would imagine that this would make the problem worse. I think the first thing I will do is swap the fan out and print at 190. I've had nothing but issues with the fan, starting with the connector being installed backwards straight out of the box. I didn't even notice it wasn't running until the second test print. After I contacted support, they told me to flip the connector around. It must happen often enough for them to suggest that. If that doesn't work, I'll try a new nozzle per Fred's recommendation. Thanks to all for the suggestions. I'll keep you posted as to what I find. It's a bit frustrating as I've had the printer for two weeks and have not made it completely through a print yet due to various problems. Admittedly, some of the issues were due to the learning curve.

Re: Filament Bunching Inside Acrylic

2013-05-25T17:14:45Z

The fan has had a bit of a problem. When it starts up, it's very loud and doesn't sounds like it gets up to speed. I actually have to stick my finger in there to stop it and get it going again. Strange, but once I do that, it seems to quiet itself down and get up to speed. Maybe it never gets up to speed? Where would I get a new fan? Is it just a regular case fan I can get at a computer store? I've dabbled in building PCs before and it looks like a regular CPU fan.

Re: Filament Bunching Inside Acrylic

2013-05-25T17:12:43Z

Morty, this is ABS, right?

I had a very similar problem when my temp defaults kept switching to 195 when printing PLA (should be 180)

Even if it is ABS, I'd bet it is still a temp problem. You might chech the high and low temps you are cycling through at 200.

Re: Filament Bunching Inside Acrylic

2013-05-25T15:21:06Z

Softening at the top like that is sometimes caused by the motor and gear getting too hot. Is the fan on the back of the extruder working?

Re: Filament Bunching Inside Acrylic

2013-05-25T15:20:10Z

If you're sticking the guitar wire and coming in from underneath, one could imagine a clog being dislodged and then reclogging once the wire is removed, but not having experienced it, I would think extended overheating would cause filament to build up on the nozzle like artery plaque, and that would keep building up after guitar wire cleaning. How clean is the filament and room you're printing in?

Filament quality can definitely play a factor, but I've never used Solidoodle's own plastic so I don't know how good it is beyond several people going with it since it is the same vendor as the machine itself. I've gone through about 20 spools and I have an assortment of about a dozen colors spread across 4 brands, and I notice few differences and only a 5 degree spread in optimal running temperatures, but others have reported more spread. I've had two bad spools total and those had that effect I mentioned of the drive gear digging into the plastic issue.

It sounds like a good idea to try .3mm for a bit, but I don't see why .1mm should be a problem with a well-leveled printer (I typically print at .3mm but it's because I print a lot and need speed and do acetone finishing for smoothing).

Re: Filament Bunching Inside Acrylic

2013-05-25T14:20:00Z

Thanks Fred. I'll try to print at a lower temperature first. Do you think the nozzle could still be partially clogged even though I can pass the guitar string straight through? I've been printing at .1mm. Maybe I'll try .3mm and see if it does the same thing. I'm also not using Solidoodle filament. Do you think that could have something to do with it? I've seen people print with this filament though.

Re: Filament Bunching Inside Acrylic

2013-05-25T13:00:48Z

I think this is normally caused by clogging in the nozzle from overheating or misalignment of the PEEK relative to the jigsaw or by heat traveling up the filament and softening it to the point that it is easier to bend than extrude.

Misalignment and clogging can be checked by simply disengaging the idler bearing tension and manually pushing to extrude plastic. If it feels relatively easy, I would think it could be softening, and I'd try printing colder.

I print ABS at 190-195, but I haven't heard of deteriorated plastic causing clogging at 200 unless there are additional causes like too much backpressure because the nozzle is too close to the bed or the flow rate is too high like you're wondering, but in those cases, I usually see the drive gear digging into the filament and lose traction before the plastic would bend like that.

Since you can get 30 minutes of printing, I would check calibration as per http://wiki.solidoodle.com/flow-rate . If it's high, then yes, your putting too much through.

Not being too patient, I'd probably try switching out the nozzle fairly quickly to see if that fixes the problem and dump the old one in acetone for a week.

Filament Bunching Inside Acrylic

2013-05-25T11:39:04Z

Hi,
I've been having trouble printing for more than 30 minutes without the filament bunching up inside the PEEK. Sometimes it gets so bad I have to completely take the Acrylic apart to get at the clog. Each time I clean it out with a thin guitar wire, it seems to do the job, but it's only temporary. After another 30 minutes of printing, it does the same thing. Is the flow rate too hight? Heater is heated to 200C. Any suggestions would be greatly appreciated.