motor strenght

Hi,

I have some problem with the extruder motor: it lose some step, it seems like it isn'n strenght enough to extrude...

if I try to load the filament quickly than 5mm/sec, the motor start to click, and the same happen during the print.

Anyone that can remember me the string that I have to inserti in my config to increase the step motor current?

(i've try to search in the forum but every search I try give me 0 results...)

thanks

Hi Zonzo

M906 X1000 Y1200 Z800 E1200 ; Set motor currents (mA)

Erik

Maybe you should check the nozzle for an internal obstruction. It shouldn't really take that much current if the filament delivery system is healthy.

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RS Components Reprap Ormerod No. 481

thanks Erik, and also thanks Radian,

I found that problem when I update the firmware after a long time, so I'm sure to have already change the mA set on my old config file, but I don't remember if I've change also the Extruder...

in any case a quick check to the noozle is a good idea

actually I've this set:

M906 X800 Y1000 Z800 E800 ; Set motor currents (mA)

so my first step is to set the E1000 to see if that is enough

Quote
Zonzo
Hi,

I have some problem with the extruder motor: it lose some step, it seems like it isn'n strenght enough to extrude...

if I try to load the filament quickly than 5mm/sec, the motor start to click, and the same happen during the print.

Anyone that can remember me the string that I have to inserti in my config to increase the step motor current?

(i've try to search in the forum but every search I try give me 0 results...)

thanks

I would not expect to be able to extrude much faster than 5mm/sec unless you increase the nozzle temperature above the normal printing temperature. 5mm/sec at the extruder is equivalent to about 50mm/sec at the nozzle, assuming a 0.5mm nozzle and 1.75mm filament. 10mm/sec would be equivalent to 100mm/sec.

It is important that when the nozzle is obstructed or you are trying to extrude too fast, the current is low enough for the motor to skip steps. Otherwise, the hobbed insert will chew a notch into the filament, and extrusion won't restart when the nozzle obstruction is removed. So be careful not to set the motor current too high. I use 1000mA extruder motor current on my Ormerod.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks David.

I'm sorry for the bad explanation: my E motor skip step when I load filament on the ptfe tube at a speed more than 5mm/sec, i have write extrude but I mean forward.

Aniway all the information is good information, my print have just finish so, during the lunch I'll check the noozle for obstruction, then I decide if still necessary to set the mA to 1000
thanks.

A current of 800mA should be plenty to load filament (not extrude) at far more than 5mm/s. I think your extruder must be too stiff. How easy is it to turn by hand (with power off)? Try with and without filament. If it is stiff with no filament, maybe one of the gears is rubbing against the extruder body or the gears are too tightly meshed (gear wheels a tad too big), or you have not assembled it quite correctly (e.g. missing a washer at the bearing). I occasionally put two small drops of 3-in-1 oil onto the gears.

If the extruder becomes stiff only when a filament is loaded (but not inserted far enough to reach the nozzle), then the hobbed part might be clogged or the Bowden tube has a kink or has not been drilled out where it screws into the brass part. Another possibility is that the filament has worn a groove inside the curved entrance tube (in the printed part), and is binding in that. My filament eventually wore its way right through the printed extruder and started getting wedged in the slot it had cut. I replaced the extruder body with a modified design that takes a PTFE tube in the entrance channel and have not had a problem since. You could also try printing the spring-loaded extrusion design.

Dave

Quote
Zonzo
Thanks David.

I'm sorry for the bad explanation: my E motor skip step when I load filament on the ptfe tube at a speed more than 5mm/sec, i have write extrude but I mean forward.

Aniway all the information is good information, my print have just finish so, during the lunch I'll check the noozle for obstruction, then I decide if still necessary to set the mA to 1000
thanks.

did you use a 2mm drill after you put on the bowden brass end? this could be cousing some problems loading the fillament into the bowden ptfe tube if you did not.

Edited 1 time(s). Last edit at 06/15/2015 02:16PM by Darathy.

Ok,

This morning I've print the spring loaded extruder, and after check the nozzle (that's look clean) I've tried it... Incredible how much the spring work!
I've print the one with the ptfe tube inside exactly ad your recent suggestion.

Before left office I've only test some quick filament feeding inside the tube without change the mA, no step was left.

Tomorrow in the morning I want to print a plate of upgrade with ABS and then the final test for that extruder is a low quality PLA gold filament with irregular diameter.

I let you know if tomorrow I've again problem