1 Topic by nevrgonastopme00 (edited by nevrgonastopme00 2013-05-23 18:18:00)

  • nevrgonastopme00
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Topic: Highest flowrate without extruder gear skipping

I have an SD2, and it seems that whenever I NEED to get something done, I have issues.  I don't think I am fighting a clog, but I will still try and clean it out.  I was curious what a good flow rate is?  I never had luck, ever, with the default configurations, be it skeinforge or slic3r.  The default flow rate would always cause my extruder gear to skip.  I can't seem to find an acceptable number any where. 

So I ask here, what kind of flow rate (in mm/s) should I be able to get out of my extruder? I set my hot end to 195C as IIRC was recommended back when I first got my unit.

In repetier, I have my manual set to 50mm/min and it still SOMETIMES skips, anything higher and it skips more often.  I have my SD2 open air, nothing is blowing on it, I have made a filament bushing for the feed hole in the back, and taped up the top angle backet to prevent dust.  There is no filament dust anywhere that I can see.

2 Reply by IanJohnson

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Re: Highest flowrate without extruder gear skipping

You might be fighting a partial clog- try poking a small wire like a guitar or violin E string into the nozzle and see if that improves.  It may only be temporary if it does.  There might also be something going on in the "cold end" at the end of the barrel inside the black PEEK.  If the zone of melted filament gets too high, it can be harder to push.  Also if a gap develops between the end of the barrel and the PTFE liner inside, it can fill with melted plastic which also causes problems.

What you can try is cooling the upper part of the hot end with a fan.  The simplest way is to take out the screw on the extruder that goes into the lower left hole on the motor.  Get a longer one (M3) and run that screw through the upper left  hole of a 40mm fan on the way back into the extruder motor. That will hold the fan in just about the right place.  You can power it with a 12v wall wart with the barrel plug cut off and replaced with a male connector to match the fan. 

My local thrift store had a basket full of wall warts, and I found a few 12v for $2, so you might have similar luck if you don't already have one lying around.

3 Reply by nevrgonastopme00

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Re: Highest flowrate without extruder gear skipping

Sounds good, ill give that a go tonight and see what happens.  I have everything laying around except a spare 40mm fan.  I am on a time crunch and wont have the time to take the hot end apart to find out whats really going on if anything >_<

Are you able to make a comment on what I should be seeing as a flow rate without the gear skipping?

4 Reply by IanJohnson

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Re: Highest flowrate without extruder gear skipping

The default of 300 should be fine for extruding into air, even up to 400 or 500.

5 Reply by elmoret

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Re: Highest flowrate without extruder gear skipping

I've printed at 175mm/s before, and extruded into air at 500mm/min before. Those are not typical - the stars aligned and I was using MG94 resin, a particularly high-flow polymer.

Filastruder - the robust, inexpensive filament extruder
E3Dv6 All Metal Hotend - the premier 3D printing hotend

6 Reply by nevrgonastopme00

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Re: Highest flowrate without extruder gear skipping

Wow.  Yeah, I definitely have something funny going on.  Thanks.

7 Reply by elmoret

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Re: Highest flowrate without extruder gear skipping

I like to keep a fresh, known good hotend on hand. Makes it less frustrating to clean one if I can still print the print I want in the meantime.

Filastruder - the robust, inexpensive filament extruder
E3Dv6 All Metal Hotend - the premier 3D printing hotend

8 Reply by nevrgonastopme00

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Re: Highest flowrate without extruder gear skipping

Tore the nozzle off, soaked it in acetone, put it back, prints like a beast now.  I am glad I have the baseline of flow now so I can tell when things are, off.  Thanks again!