After multiple jams from bulging filaments on two spools I'm getting frustrated. One, right before a job was done.
Is there something I can do to prevent these bulges in filaments from ruining jobs?
What can I do to prevent this from happening in the future before it's a disaster?
He's a picture of one I found using google.
How to catch and fix these on the fly? That would be difficult..
But this is an issue you really should not have.
Could it be an issue with filament storage?
Or is it coming from the manufacturer with these bulges? If so, I would try contacting ( you may have gotten a bad batch? ), or finding a new retailer if this happens often.
I have gone through a lot of pounds of both ABS and PLA and never come across this.
Bottom line: The easiest way to prevent this is to avoid cheap filament.
You can get mid-grade filament for a few dollars more than the ultra cheap stuff.
In other words I tried out some 10$ stuff from ebay, and while it might print for a little while it notoriously clogged in any prints greater than 1hr.
20-25$ is the going rate for mid-grade filament on amazon and check the reviews I've had good consistency there.
There is a filament width sensor design at http://www.thingiverse.com/thing:454584 -- cleverly, the author tweaked Marlin so it adjusts extrusion in real time to correct for variations.
That said, I agree with several others that buying filament with better quality control, and keeping it dry and unchewed by Labradors, should be enough. :)
That's my picture :-)
I use a filament monitor with an encoder wheel that pauses the print if the filament stops moving (because a bulge got stuck, or filament ran out, or the hot end jammed, or whatever). I have a bunch of these on multiple printers: http://www.toybuilderlabs.com/products/tunell-3d-printer-filament-monitor
The Tunell monitor works with Sailfish, Marlin, and Smoothie to my knowledge. This particular one doesn't work with Repetier, but you can wire up a simple encoder wheel to use Repetier's filament monitor functionality.
Like other people have mentioned, you should avoid cheap filament, and return spools with bulges. I personally only see bulges like that maybe every 20 spools or less.
