Extruder stops working?

Just started running the Tantillus after a few weeks off. Did a test print Yoda head yesterday, and it worked fine up until about 95%, then the extruder gear seemed to just stop turning. No skips on the motor or anything, and it doesn't look like it's jammed or trying to turn.

Was able to unload and re-load the filament and it would stop/go/stop/go at regular intervals but otherwise worked fine. "Purge 5mm" however was unresponsive.

Just did another print, and it extruded the outline and first layer border of the print, but stopped extruding again when it got to the first layer solid infill. Tried again, and nothing is extruding now, not even the borders. Checked the RAMPS connections and everything else I could think of looks pretty normal.

If it makes a difference, we just finally got our SD card reader in the mail so these are our first prints NOT using Pronterface.

Any ideas?

Thanks

Edited 2 time(s). Last edit at 12/20/2012 01:58PM by Hobocop.

Maybe a clogged hot end building up backpressure?

You could take the extruder motor off the extruder and run a test print with it still hooked up to RAMPS, that way you can isolate the electrical from the mechanical. If the motor runs the whole time then I'd think it's probably a jam/friction or something else mechanical.

Also seems like it could be a loose/intermittent electrical connection, but sounds like you already checked that.

That's all I can think of at the moment, good luck

Edited 1 time(s). Last edit at 12/20/2012 05:34PM by Eric Young.

There is a small chance that it is the driver miss behaving. The original drivers shipped with the kits had a very finicky current setting and if it is at all too high it will slowly over heat and shut off. If this is what happened on the Yoda then maybe the driver got hot enough to effect the heat sink or soldering and now it shuts off earlier. To test try turning down the current a tiny tiny tiny bit and see if it works again. If it does than that is your problem and you should contact me directly and we will see if we can exchange that driver for one of the newer ones.

Other possible issue is with the temperature. If the thermistor wires are loose it will trip the temperature protection and the extruder will stop. If this happens it will say Dwell on the LCD screen or you will see the temp drop below room temperature or go way above expected temp.

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Thanks guys,

I took the extruder motor out of the assembly and ran a test-print, and the motor did not turn at all. It can be turned manually with little effort no problem. I will look over the instructions and try to figure out where to turn the current down.

Additionally, the temperature does fluxuate a lot more than it did previously when hooked up to pronterface. Typically it heats up VERY fast, hits 200 in about 20-30 seconds where it would take at least a full minute before. The temperature peaks around 220, then slowly fluxuates down to about an even 200-204 before starting to print. No "Dwell" on the screen and otherwise seems like everything is normal.

Cheers
Jon