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Issues with A20M after Feeder upgrade.

Posted: Wed Aug 07, 2019 10:17 pm
by Engineero
I bought the Aluminum Feeder upgrade for feeding the filament into the Bowden 2-1 hotend, and have had problems since.
https://www.amazon.com/gp/product/B07KQ ... UTF8&psc=1

I am using the Firmware with 3dTouch from this forum.
The two filament feeders are using the same motors that came with the A20M machine.

Since using the new feeders, at first it was over-extruding and causing the Stepper gear to slip on the filament.
After reading a few posts, and watching a few YouTube videos, I tried to dial in the feedrate in the configuration.H in the firmware with these settings.

I changed the default 430 steps on E0 to 100 to try and slow the feedrate.

Code: Select all

/**
 * With this option each E stepper can have its own factors for the
 * following movement settings. If fewer factors are given than the
 * total number of extruders, the last value applies to the rest.
 */
//#define DISTINCT_E_FACTORS

/**
 * Default Axis Steps Per Unit (steps/mm)
 * Override with M92
 *                                      X, Y, Z, E0 [, E1[, E2[, E3[, E4]]]]
 */
#define DEFAULT_  { 80.3, 80.8, 400, 100 }   //Orig { 80, 80, 4000, 500 } 93*2 = DRV8825 1/32 Stepps //430 original default E0

/**
 * Default Max Feed Rate (mm/s)
 * Override with M203
 *                                      X, Y, Z, E0 [, E1[, E2[, E3[, E4]]]]
 */
#define DEFAULT_MAX_FEEDRATE          { 400, 400, 400, 45 } //Orig { 300, 300, 5, 25 } //1.0.3 { 300, 300,20, 25 }
Now the stepper motor itself is under-extruding, but also the stepper motor shaft is skipping it turns, then I hear a bump and it rotates backwards.

I run my filament for a print between 200-210, and get oozing at around 175 degrees (pre-print)

Is my motor going bad? or when I changed the AXIS_STEPS_PER_UNIT for the extruder did it throw something off so that the stepper motor isn't locking at the proper step points?

I don't know what to do, can someone help me out on this?

Re: Issues with A20M after Feeder upgrade.

Posted: Wed Aug 07, 2019 11:10 pm
by _kaktus_
Hello.
:mrgreen:

If the diameter of the gear wheel in the extruder has changed, the correction of the parameters seems justified.

Did you dismantle the Teflon bowden tube completely :?:

Re: Issues with A20M after Feeder upgrade.

Posted: Thu Aug 08, 2019 1:07 am
by 3DAngel
I'm new too to the A20M; but isn't there in the config.h you need to change to the geared extruder?
also, if changing feeder, you need to test the feed and do the proper math and then adjust in the FW's config, right? :?:

Re: Issues with A20M after Feeder upgrade.

Posted: Thu Aug 08, 2019 1:40 am
by Engineero
By "Did you dismantle the Teflon bowden tube completely"
Do you mean, did I dismantle the old feeder attached to the Stepper motor?
Yes, the plastic gear on the E0 metal gear/driveshaft was slipping when the gearshaft rotated, somehow they had separated since its not 1 solid piece. (the left hand primary feeder)

I'm not sure about other settings in the FirmWare as to adjustments for swapping gear sizes, the original had a gear as well, except it was concave, and the idler that applied pressure was a flat edged bearing. The new Feeder is all metal and the drive gear is larger diameter but straight cylinder, but with a Grooved Idler applying the pressure against the filament.

I'm just wondering if there is another way of adjusting the stepper in the FW on the motor, If it needs that many E-Steps to function properly per step rotation, and need another way to dial up or down the feedrate.

Maybe something I missed?

Re: Issues with A20M after Feeder upgrade.

Posted: Thu Aug 08, 2019 2:22 pm
by _kaktus_
Hi.
:mrgreen:

I asked if you removed the Teflon tube completely.
I mean, I was wondering if you took the other end out of the throat of the head block.
The symptoms you describe can also occur when the tube is not inserted correctly (to the very end) in this place.

In my model, I can set the number of steps/mm in the printer menu.
look for YT videos that show how to calibrate an extruder using a 10cm section of the filament. ;)

Re: Issues with A20M after Feeder upgrade.

Posted: Sat Aug 10, 2019 10:17 pm
by Engineero
Yeah, the tube is fitted to the teflon tube quick-detach all the way into their endstops on both the hotend and the feeder.

I also took out the quick-detach and nozzle to check if there was any built up melted or leaking filament, everything is clean.

I'm also still getting alot of oozing during warmup and shutdown, is that a sign I've still got an over-feed issue with pressure inside the hotend?

Re: Issues with A20M after Feeder upgrade.

Posted: Sun Aug 11, 2019 12:43 am
by _kaktus_
Hi.
:mrgreen:

Yeah, it's possible.