I have a twin extruded Rostock Max, and normally use Ex1 for ABS / Ex2 for HIPS. Today I ran an ABS only print and got terrible extrusion... very gappy 'dotted line' feed coming out of the nozzle.
http://s16.postimg.org/y62hxwwhh/DSC_0061.jpg
Thinking the nozzle could be blocked, I swapped over the feed hose to the hot end of Ex2, but got identically terrible extrusion of ABS from that nozzle. I then re-hooked up the HIPS to Ex2 and am now printing the part without any problems in HIPS.
Has anyone experienced such under-extrusion problems in a similar situation? my first port of checking tomorrow will be the extruder / feeder for the ABS, I am wondering if the drive wheels are not gripping the filament properly so are unable to push it through the nozzle sufficiently.
Gappy extrusion with ABS, no problems with HIPS?
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kanDO_Bryce
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Re: Gappy extrusion with ABS, no problems with HIPS?
Can you give some more info, like temps, print speeds, nozzle diameter, hotend (assuming E3D?) and which extruder you're using (assuming the EZstruder?)
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kanDO_Bryce
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Re: Gappy extrusion with ABS, no problems with HIPS?
I am running:
2 x 0.5mm nozzles - Both nozzles at 230 C
ABS extruder set to 130% extrusion multiplier / HIPS extruder set to 90% extrusion multiplier
2 x SeeMeCNC Bowden Hotends
2 x Steve's Extruder
Speeds - this is what my speeds are when set to 'Fast'
Print Speed: 60mm/s
Outer Perimeter Speed: 60mm/s
Infill Speed: 100mm/s
Speeds - this is what my speeds are when set to 'Slow'
Print Speed: 40mm/s
Outer Perimeter Speed: 30mm/s
Infill Speed: 60mm/s
I get the same extrusion issue at 'Fast ,'Slow' and at settings in between. Also, the first layer goes down much slower than the rest.
2 x 0.5mm nozzles - Both nozzles at 230 C
ABS extruder set to 130% extrusion multiplier / HIPS extruder set to 90% extrusion multiplier
2 x SeeMeCNC Bowden Hotends
2 x Steve's Extruder
Speeds - this is what my speeds are when set to 'Fast'
Print Speed: 60mm/s
Outer Perimeter Speed: 60mm/s
Infill Speed: 100mm/s
Speeds - this is what my speeds are when set to 'Slow'
Print Speed: 40mm/s
Outer Perimeter Speed: 30mm/s
Infill Speed: 60mm/s
I get the same extrusion issue at 'Fast ,'Slow' and at settings in between. Also, the first layer goes down much slower than the rest.
Re: Gappy extrusion with ABS, no problems with HIPS?
Shoving the extrusion multiplier up to an extreme won't help you any. In fact, don't screw with the extrusion multiplier, really ever. Its only going to cause you more issues than it will solve.
If you want to get your extrusion set correctly you'll need to calibrate your extruder, and measure your filament. Generally how I do it is I disconnect the bowden tube at the hotend, cut the filament flush with the end of the tube, and tell the host application to extrude 100mm of plastic. Then I take a measuring device (usually a 6" steel rule) and measure how close it is to 100mm, then I divide 100 by the measured amount and multiply that by the current steps per mm in EEPROM. I repeat this until I get close enough (you can decide whats "close enough").
The next SUPER important thing is to measure your filament, and put this in your slicing engine. It needs to know the true diameter of your filament so it can extrude the correct amount. This will help you out a lot.
The other thing thats probably causing your issues, 230C is on the low end of where ABS can print, and in many cases it doesn't extrude well. I would definitely try bumping it up to 235-240 at the minimum. Also the Steves is pretty heavily geared, you may have issues at those speeds as the stepper may be running on the high end of its speed range. More likely its the temp though.
If you want to get your extrusion set correctly you'll need to calibrate your extruder, and measure your filament. Generally how I do it is I disconnect the bowden tube at the hotend, cut the filament flush with the end of the tube, and tell the host application to extrude 100mm of plastic. Then I take a measuring device (usually a 6" steel rule) and measure how close it is to 100mm, then I divide 100 by the measured amount and multiply that by the current steps per mm in EEPROM. I repeat this until I get close enough (you can decide whats "close enough").
The next SUPER important thing is to measure your filament, and put this in your slicing engine. It needs to know the true diameter of your filament so it can extrude the correct amount. This will help you out a lot.
The other thing thats probably causing your issues, 230C is on the low end of where ABS can print, and in many cases it doesn't extrude well. I would definitely try bumping it up to 235-240 at the minimum. Also the Steves is pretty heavily geared, you may have issues at those speeds as the stepper may be running on the high end of its speed range. More likely its the temp though.
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kanDO_Bryce
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Re: Gappy extrusion with ABS, no problems with HIPS?
Thank you very much Mike - after tightening the axle on the extruder (the rollers were indeed slipping) I went through the things you suggested, one by one, changing the setup. With each change I saw an improvement in print quality - printing slower and increasing the temperature made the most noticeable differences. It went from very shabby to nice and tidy!
Now to try printing something a little more demanding than a 15x15x7mm block and see if it still behaves...
Now to try printing something a little more demanding than a 15x15x7mm block and see if it still behaves...