Prusa Mendel i2 Extrusion Problem

Hello all! I recently built an i2 Prusa Mendel, and it has been working great. A couple days ago it suddenly stopped extruding (extrudes very slowly). I figured I might have developed a clog in the nozzle, so i attempted to clean it. Same problem. So I bought and installed a new hot end. Same problem. The strange thing is the feeder has more than enough power to feed the filament. So my question is what could be the problem?

The filament that does come out seems to have bubbles in it. Its ABS, and the hot end is set to 230, but because of this problem I've tested it at several other temperatures also.



PS: I've also changed out the RAMPS 1.4 board with a spare that I keep around for good measure.

Thanks in advance to anyone who can help!

Have you checked the extrusion length without load (no hotend tip)? This tells you if it's a calibration of drive issue.

If it does ok with no load, try it with a little loading (lightly grip the ingoing filament) if that makes it fail then you have a grip problem (dirty hob, missalignment) or a friction issue (hob missalign, bearing issue) or your driver/motor isn't powering.

Sorry I don't have the experience with the RAMPS to say how to check the correct stopping and amperage is being supplied (I have multiple extruders/heats, so I swap with a "known good" for testing things like that)

The hobbed bolt was my first suspect, but it seemed decently clean, but I still cleaned it and got the same problem. It almost seems like the problem has something to do with the Arduino not working right with RAMPS, I have reloaded its firmware only to run into the same issue. I'm running Sprinter.

Edited 1 time(s). Last edit at 12/19/2014 02:42AM by joshuah459.