Insufficient extrusion after retraction FIX!!!
Posted by galaxyman7
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Insufficient extrusion after retraction FIX!!! June 09, 2016 03:03AM |
Registered: 15 years ago Posts: 198 |
Hi everyone! I have had problems with under extrusion after retraction for a while, and I never knew why! See the attached picture to see what I'm talking about. I would call it webbing, stringing, gaps, , localized under extrusion, etc. It only happened after doing a lot of small moves. I ended up trying to reduce the retraction speed from 100mm/s to 40mm/s, and it worked! I had no idea why it worked until someone on facebook told me that there is a limit in firmware for 50 mm/s... so basically the gcode is telling it to go faster than it can go, and it retracts too much as a result. So either you reduce the retraction speed below 50mm/s, or increase firmware limits.
Just an FYI for anyone having trouble out there. I know I searched all over the place and couldn't find a solution, so hopefully people can find this post on google or something.
Just an FYI for anyone having trouble out there. I know I searched all over the place and couldn't find a solution, so hopefully people can find this post on google or something.
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Re: Insufficient extrusion after retraction FIX!!! June 09, 2016 04:50AM |
Registered: 9 years ago Posts: 3,525 |
Its good to post solutions.
Often people set in their slicer a retraction speed such as 150mm/s which is a) not possible for their extruder to actually produce or b) limited by the maximum feedrate in their firmware. You can turn those maximums up if you first test to see if your motor can reverse at the speed you're asking it to, which can be improved by getting the current right or considering gearing etc...
Another fix is to add a little extra length on restart, I find about 0.05mm just prevents the first 10mm of perimeter after a layer-change-retract from being stringy. Any more and you risk over-extruding around areas with a lot of fine detail and therefore multiple retracts in short succession, the little extra length's add up.
Simon Khoury
Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
Often people set in their slicer a retraction speed such as 150mm/s which is a) not possible for their extruder to actually produce or b) limited by the maximum feedrate in their firmware. You can turn those maximums up if you first test to see if your motor can reverse at the speed you're asking it to, which can be improved by getting the current right or considering gearing etc...
Another fix is to add a little extra length on restart, I find about 0.05mm just prevents the first 10mm of perimeter after a layer-change-retract from being stringy. Any more and you risk over-extruding around areas with a lot of fine detail and therefore multiple retracts in short succession, the little extra length's add up.
Simon Khoury
Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions
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Re: Insufficient extrusion after retraction FIX!!! June 09, 2016 11:47AM |
Registered: 9 years ago Posts: 413 |
Thanks for the Fix galaxy...
This could explain issues others have had and on the face of it looks like a software bug in the firmware.
You would expect the firmware to just replace your 100 speed with 50. Since its under extruding its either retracting a longer distance or just not feeding until some time limit.
This could explain issues others have had and on the face of it looks like a software bug in the firmware.
You would expect the firmware to just replace your 100 speed with 50. Since its under extruding its either retracting a longer distance or just not feeding until some time limit.
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