HELP! Brass Extruder Nozzle Rubbing on My Prints!

Hi All,

I am a brand new RepRapper. I just put together a Huxley. I got a kit from RepRapPro.

I thought I had successfully calibrated the machine, having successfully printed some nice calibration cubes, but I have run into a difficult problem!

My extruder nozel starts to rub/drag against the objcet it is printing. The still hot pliable form squishes and bends as the extruder continues to chug along extruding filament.


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This Companion Cube got rubbed on till I canceled him.

Whats worse is, it seems to happen on more so solid objects; almost as if the more solid printed parts are expanding.

Can anyone help me? What is causing this?

try lowering the temperature a little, also try a fan blowing on the part.
check your esteps too.
print something with a couple of solid layers, after the third layer examine how it's printing, if there's too much try send an M92 Exxx
ie if your esteps are currently say 700, send M92 E680
if your esteps are too low you'll start to notice slight gaps between the extrusions

Hey Brother,

Thanks for the advice much. I appreciate your thoughts.

Per your advice, I grabbed my big fan and am building another companion cube... I need one to keep me company

I would have played with the temp, I had already started my print when I saw your post... Doh! Ah well. I will play with the temps for sure.

The Prints that were getting drug on were PLA printing at 205C; do you think that is a bit too hot?

I had already calibrated my extruder's steps per mm. I have bee, marking of 110mm of filament, heating up the hot end, and then running 100mm through the extruder. By measuring whats left of the 110 i marked off, I can derive a ratio to multiply my esteps by to get a more appropriate value. It it overkill to calibrate this way? Should I just run the filament through the extruder (bowden extruder) and not actually waste the filament through the hot end? I figured that calibrating my esteps by running the filament all the way through the hot end would provide the most accurate results.

Thanks so much for your advice. I sure hope I can figure out this extuder rubbing problem!

-Adam

yeah depending on your hotend, 205 is way high.
I print PLA at 185

if you've calibrated your esteps that way they should be fairly close, have you also measured the diameter of your filament?
measure it with a calliper in a couple of different places along the length, and also check whether it is round rather than oval
average it out and use that number in slicer for the filament diameter.
I still examine the first few layers and mess with the esteps during print anyway.

you can change the temp of your hotend during the print too. using pronterface just set it to whatever.

Thanks yo your advice, I have gotten a couple of successful prints! You the man!

Now to keep experimenting