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Solved--Extruder step question

Posted: Thu Mar 08, 2018 6:21 am
by JohnDeere630
Hello,
I have an I3 Aluminum printer, with a lot of upgrades. I posted what I did and how as a sort of mini how-to on the forum some time back, and since than have added different Z screws and steppers, and a filament runout sensor.

Anyway, the printer works fine with my chosen material (ABS), but I have an issue that I have never been able to figure out. I had to replace the extruder early on, and no matter how I figure it, it should be 93 pulses per mm (1.8 degree stepper, 1/16 step, running a feeder wheel of 34.39mm circumference.) The default in the firmware was 95, so I'm close, but if I run it any higher than about 82 pp/mm, I get a globby mess which I assume is over-extruding. Obviously, I am overlooking something. Currently I'm running 82 pulses per mm.

Can anyone shed some light on what I am missing? TIA!

Re: Extruder step question

Posted: Thu Mar 08, 2018 6:13 pm
by William
Have you tried to swap the A4988 of Zaxis and extruder?

Re: Extruder step question

Posted: Fri Mar 09, 2018 2:05 am
by JohnDeere630
[quote=William post_id=83035 time=1520504017 user_id=51382]
Have you tried to swap the A4988 of Zaxis and extruder?
[/quote]

I have. It made no difference.

Re: Extruder step question

Posted: Fri Mar 09, 2018 4:14 am
by JohnDeere630
[quote=William post_id=83035 time=1520504017 user_id=51382]
Have you tried to swap the A4988 of Zaxis and extruder?
[/quote]

I have. I've tried 3 different A4988's, and 2 different steppers. All with the same results.

Re: Extruder step question

Posted: Sat Mar 10, 2018 4:23 am
by JustinSB
This is what you're missing:
http://print.theporto.com/posts/how-to- ... der-steps/

You need to calibrate your extruder steps, & then you need to research "Extrusion Multiplier", as that will probably be your next step, once you've got your extruder working accurately.

Re: Extruder step question

Posted: Wed Mar 14, 2018 2:42 pm
by JohnDeere630
Thanks, guys. I found it. I feel pretty foolish. For some reason, and I really don't remember changing it, the extrusion multiplier in Repetier was set at 1.1. Setting it to 1 solved the problem.