Any ideas??

Hello everyone. My printer has been going like a champ for a few weeks now but since I put ABS in it, and even moved back to PLA, everything has been looking like this:

I have no idea why. I thought maybe it could be that the extruder isn't clean, but when I manually extrude it with repetier host, it works fine. I'm just completely lost. I've tried everything I could think of. If anyone has any ideas, please help. The first layer seems to be okay, though sometimes the width of each line varies randomly, but every layer after that is extremely spotty. It's like it works for a mm and then doesn't, works for 2mm and then doesn't Please help if anyone has any ideas. Thank you!

You need more flow. I'm running at 240c but until I mounted a fan where filament enters the extruder and eventually a finned hotend I couldn't raise feed rate because filament was melting above the cool zone causing jams. Since fan install I'm getting 100mm/sec movements with no jams.

The only issue is that it used to work with PLA, but now it isn't even with the same settings. The only thing I changed was I added a piece of cardboard between the aluminum and hot plate so it can get hot enough.

You may have changed something in your slicer for abs and not switched back to all the same settings for pla.
I use cura and save my configuration for each nozzle size, i regularly swap between 0.5mm and 0.3mm nozzles, each material type, abs, pla, nylon, ninja flex.
Even down to colour if i find much difference in the way the filament behaves.

that way i can quickly load a basic configuration for what im printing and then tweak it.

Gordon

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Gordon
Currently have a tweaked mendel prusa i2
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If you look in the image, the problem is that it isn't shooting out the same amount of filament each time. It prints it wide then thin then wide then thin. I know it isn't too fast or anything because it worked perfectly before. I will say that I'm using a Chinese jhead, but I just don't understand.

Well I only changed the temp is the issue. I went ahead and started back to default and that didn't even work.

My prints looked the same, until I raised the z-endstop. It seems your nozzle is too close to the table?
-Olaf

I've tried every height I could think. Thank you though.

I've tried both these settings:


The second image is my normal settings.

So what hot end temperatures have you tried?

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

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dc42
So what hot end temperatures have you tried?

I'm using what I always did. That's what's so confusing. I was getting perfect prints from PLA. Now I get horrible prints. The temps ive tried are from 200-210. Bed temps are 55 for first layer and 50 for all others. I just don't see how it could be any of that because it used to work so well. I use the glue for adhesion.

Edited 1 time(s). Last edit at 05/17/2015 03:53PM by fatesalign.

My guess is that your filament feed system (hobbed bolt?) is to tight or to loose. You may not notice this problem when using manual extrusion.

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Prusa I3 kits www.schufco.com

Unfortunately it's not a hobbed bolt, but I've tried to loosen/tighten it etc.

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but since I put ABS in it...

There might be a little ABS left in the nozzle coating the outlet, so the actual diameter is smaller now.

Try to heat up the extruder to ABS-temps and manually push some PLA through it to clear the nozzle. Or change the nozzle with a new one.
-Olaf

Edited 2 time(s). Last edit at 05/18/2015 04:02AM by o_lampe.

Is the hot end holding the setpoint successfully? If the power supply is maxed out running the bed and hot end, some stray air currents on the hot end or lost insulation could cause the hot end to be unable to keep up, allowing the temperature to fall below what can successfully be extruded at the speeds you're using.