Extruder steps do not change how much filament is extruded!

[PaulB]

Hi All,

I have been suffering from poor and inconstant quality prints for a while now and have tried pretty much everything that I can think of. One of the threads was leading towards not calibrating the extruder steps which I had successfully done right back at the start (changed from 93 to 100 in the EPROM). I checked by extruding 50 mm of filament and it only moved 35!! Did the calculation and adjusted the steps, got 45 mm movement, tried just increasing by (I think) 3 and had 65 mm extruded. Took the 3 steps off to go to where I had 45 mm and this time I only extruded 25 mm!!!! Regardless of what I do the extruder extrudes what it wants to, some times when I add steps I get less movement than on the previous setting!!
Filament moves freely, the hob rotates smoothly, no slipping/ skipping/ jumping. Same result hot with nozzle (0.4 mm, diameter checked) or without nozzle hot or cold. Memory re-set performed and yes, I do always press 'Store Memory', no matter what I do I cannot calibrate the extruder steps.

One thing that is strange, I have the GT2560 Rev A and I only have 4 stepper drivers, the first 2 pages of the instructions show 5 drivers and then suddenly it shows 4!

So, should I have 5 stepper drivers? Is my board shot?? Any ideas???

Thanks in advance,

Paul

[William]

Hi，you can calibrate the extruder by following this video:https://www.youtube.com/watch?v=fb7lit5 ... e=youtu.be.
As to the amount of stepper drivers,I wanna know which machine do you have?If the machine only have one extruder,4 stepper drivers are enough.

[PaulB]

Hello William,

thank you for the reply. I have tried the calibration procedure several times, that is what has highlighted that I have a problem, I get different readings every time regardless of what the steps are set to.
At the weekend I tried re-loading the firmware back on (both the original and the modified for the touch sensor) and it did not help
I fully stripped down the extruder again and found that the plastic axle that holds the tensioning lever is cracked which MAY be causing the problem. I have ordered the aluminium replacement and will fit that before I proceed.

Accepting that the machine works with 4 stepper drivers would it be an advantage to fit a stepper driver to the fifth slot???

Thanks,

Paul

[PaulB]

Got the metal extruder lever yesterday and fitted it.

First test extrusion was 27 mm out so I did the calculation and 98.9 was the steps required (I had 100 prior to my problems starting) and having set that a test of 100 mm extruded 100.5 mm so I am happy. Did 2 prints which are much better but I have messed up all of my setting now in Cura!!!!

I will test the calibration again but so far this seems to have been the problem.

Paul

[PaulB]

Around 10 prints and 3 - 4 calibration checks and I can now report that the problem was solved by fitting the metal lever. Everything working fine and changing the number of steps now changes the amount of filament extruded as it should.

However, I now have my extruder clicking occasional so I need to look at that and my touch sensor has just died.

One day I may get my printer up and running reliably for more than a few prints......

PaulB