Stepper extruder looses torque When I power up my mendel and open the reprap host software, the X, Y, and extruder stepper motors lock up, as they should. The holding torque is adequate on these steppers. When I press "extrude" in the host software, the extruder stepper steps the correct distance, but with very little power (and a bunch of buzz/beeping, which I understand to be normal without a separate stepper driver). The extruder stepper twitches and misses steps, and can be stopped completely with little force. I played with the potentiometer and couldn't gain enough torque to extrude consistently, then restarted the machine (remember full holding torque on startup?) well, I blew the A3949 chip (td) doh.. I replaced the chip (waiting for parts sucks!) and returned the pot to where it came set to. The problem exists still. I'll try tomorrow to transplant one of the axis stepper boards to drive the extruder, and report back my findings. I'm using the following: Windows7 RepRap java host The latest FiveD_GCode and Extruder firmware Techzone electronics Lin Engineering NEMA17 Motor No.: 4118S-15-13 rated current/phase 0.5Amps resistance/phase 15Ω Any suggestions? I tacked on an image of the blown chip, don't do what I did kids! Thanks, Braden https://reprap.org/forum/read.php?13,52497,52497#msg-52497 Sat, 13 Jun 2026 17:08:49 -0400 Phorum 5.2.23 https://reprap.org/forum/read.php?13,52497,57493#msg-57493 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,57493#msg-57493
I think the alterations plugins may only be in later versions of Skeinforge which are here:-

[fabmetheus.crsndoo.com]

I always use the latest version as Enrique is improving the programme all the time. I have rarely had any problems and when I have Enrique has responded very promptly.

I always delete the old version directory completely as the directory structures have changed over time and if you don't have a clean install you are likely to run into problems. I usually install in a newly created directory and test from there before I delete the older version.]]> emt Controllers Wed, 01 Sep 2010 10:00:17 -0400 https://reprap.org/forum/read.php?13,52497,57360#msg-57360 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,57360#msg-57360 -------------------------------------------------------
> Replacing M108 S### with M108 R###
>
> S (tab) R in replace.csv should do it. Will change
> all S to R.
> For specifics you can I believe put M108(space)S
> (tab) M108(space)R

I tried creating a replace.csv with "M108 S(tab)M108 R" and then again with "S(tab)R" in the skeinforge main directory, skeinforge_tools, and tried putting it into a new directory called alterations, within the main skienforge directory, since I saw mention of it on a search for "skeinforge replace.csv".

Unfortunately every time I opened the .gcode output in ReplicatorG, M108 S was unchanged.


gr0k Wrote:
-------------------------------------------------------
> I still haven't tried it yet, but take a look at
> this rpmify skeinforge plugin:
> [groups.google.com]
> d2edbaec22?pli=1


Not entirely sure how to use this plugin, I'm reading through the Skeinforge documentation now, but help is always appreciated!


I read in wiki.makerbot.com that you need to preempt M108 R commands (RPM) with M108 S (PWM)(once per Gcode) to set PWM for the stepper, is this required for a dedicated stepper driver, or just the H bridge hack?

I'm using Skeinforge for makerbot, which I found here. (since I'm running makerbot firmware, I assume that this is the best option?)

Sorry for all the questions, the learning curve is steep, I really appreciate the help.
-Braden]]> Braden Kear Controllers Tue, 31 Aug 2010 07:43:53 -0400 https://reprap.org/forum/read.php?13,52497,57135#msg-57135 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,57135#msg-57135 > Now I just need to figure out how to use the
> skeinforge plugin to find and replace M108 S###
> with M108 R###

I still haven't tried it yet, but take a look at this rpmify skeinforge plugin: [groups.google.com]]]> gr0k Controllers Sat, 28 Aug 2010 18:39:49 -0400 https://reprap.org/forum/read.php?13,52497,57051#msg-57051 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,57051#msg-57051
S (tab) R in replace.csv should do it. Will change all S to R.
For specifics you can I believe put M108(space)S (tab) M108(space)R]]> emt Controllers Sat, 28 Aug 2010 05:24:11 -0400 https://reprap.org/forum/read.php?13,52497,57006#msg-57006 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,57006#msg-57006
I pushed another nozzle out of the barrier though (td) will rebuild tomorrow

Now I just need to figure out how to use the skeinforge plugin to find and replace M108 S### with M108 R###]]> Braden Kear Controllers Fri, 27 Aug 2010 18:15:57 -0400 https://reprap.org/forum/read.php?13,52497,56905#msg-56905 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56905#msg-56905
In the meantime, I was able to slow the Z feedrate in ReplicatorG's outputted G Code by lowering the max rate in the machines.xml to 75 for now.

Since I fixed one problem, another has arrived! the extruder stepper motor gets HOT! hot enough to melt the PLA of the extruder block.

Changing the position of the stepper board's pot has no effect on the heat of the motor.. hmm...]]> Braden Kear Controllers Thu, 26 Aug 2010 17:20:18 -0400 https://reprap.org/forum/read.php?13,52497,56822#msg-56822 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56822#msg-56822
I understand Skeinforge uses some M functions internally even if your firmware does not need them.
You can play with replace.csv in the Skeinforge alterations directory to change the final output in the G code.]]> emt Controllers Thu, 26 Aug 2010 05:17:09 -0400 https://reprap.org/forum/read.php?13,52497,56751#msg-56751 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56751#msg-56751
I'll try this out when I get home later, but I still wonder why Skeinforge used M113 in it's G Code, is there an option somewhere I missed?]]> Braden Kear Controllers Wed, 25 Aug 2010 18:24:43 -0400 https://reprap.org/forum/read.php?13,52497,56686#msg-56686 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56686#msg-56686
M140: Bed Temperature (Fast)
M141: Chamber Temperature (Fast)
M142: Holding Pressure

I'm worried about this one, as I do have a stepper extruder:

M113: Set Extruder PWM
Example: M113
Set the PWM for the currently-selected extruder.

Edit:

The G Code generated by ReplicatorG uses M101 to turn the extruder on and no error is generated, the command has no effect on the machine.


reading more.....]]> Braden Kear Controllers Wed, 25 Aug 2010 04:39:49 -0400 https://reprap.org/forum/read.php?13,52497,56682#msg-56682 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56682#msg-56682 [00:55:33] Error: Unknown M code: M140
[00:55:33] Error: Unknown M code: M141
[00:55:33] Error: Unknown M code: M142
[00:55:33] Error: Unknown M code: M113


I'm looking through the G Code reference page now. The firmware on the extruder is Rick Pollack's patched firmware.]]> Braden Kear Controllers Wed, 25 Aug 2010 04:33:12 -0400 https://reprap.org/forum/read.php?13,52497,56644#msg-56644 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56644#msg-56644
In replicatorG I made a skeinforge profile for Mendel-PLA, and attempted a print, but it tried to move the Z screws way too quickly, and skipped all but a couple steps. The skeinforge box that is in repG dosen't list Z mm/s in the speed menu (td). I opened skeinforge standalone, slowed Z down quite a bit, and generated G-code. In replicatorG I opened the G-code and attempted a print, this time the axes acted correctly, but the extruder didnt even try to step. I have the latest mainboard firmware, provided by replicatorG, and V2.2 extruder firmware modified for a seperate stepper board (at work and cant find the name of the author). ReplicatorG gave me some m code errors, and wont extrude in the control panel screen either.

Sorry for the lack of specifics, I'll update anything I'm missing when I get home.


Thanks,
Braden]]> Braden Kear Controllers Tue, 24 Aug 2010 18:27:21 -0400 https://reprap.org/forum/read.php?13,52497,56452#msg-56452 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56452#msg-56452 Braden Kear Controllers Mon, 23 Aug 2010 18:12:38 -0400 https://reprap.org/forum/read.php?13,52497,56351#msg-56351 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56351#msg-56351 forums.reprap.org]]]> nophead Controllers Mon, 23 Aug 2010 04:02:09 -0400 https://reprap.org/forum/read.php?13,52497,56343#msg-56343 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56343#msg-56343 Braden Kear Controllers Mon, 23 Aug 2010 03:11:23 -0400 https://reprap.org/forum/read.php?13,52497,56341#msg-56341 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56341#msg-56341
now (after reprap host locking up often) I'm trying to use replicatorG and having problems with maxhines.xml.. uggg.

I added the reprap element to in machines.xml in the replicatorG folder, but replicatorG dosen't list reprap in the menu. what am I doing wrong?]]> Braden Kear Controllers Mon, 23 Aug 2010 02:50:18 -0400 https://reprap.org/forum/read.php?13,52497,56316#msg-56316 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,56316#msg-56316
I installed a stepper driver board in place of the extruder board's on board driver.
I ran the reprap host in linux (I like the additional options in the linux version).
I changed the extrude speed between 10 and 9999.
I adjusted the driver boards pot up and down.
I swapped the stepper motor out.
I uploaded the latest firmware to both boards, with the only modification to un-comment the use thermistor line.

The extruder still jitters and moves very slowly, and also gets very hot if left idle and locked up...
Hot enough that it melted the PLA of the extruder and stripped the drive gear's ID (td)

Thanks for the help everyone.]]> Braden Kear Controllers Sun, 22 Aug 2010 21:47:11 -0400 https://reprap.org/forum/read.php?13,52497,53326#msg-53326 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,53326#msg-53326
it is similar to the code that is posted in the wiki

[www.reprap.org]]]> lunchtrayrider Controllers Thu, 29 Jul 2010 10:38:43 -0400 https://reprap.org/forum/read.php?13,52497,52946#msg-52946 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52946#msg-52946 -------------------------------------------------------
I commented out the even number
steps and left the odd numbers (so the ones that
have pwm>>1 + pwm>>3 are active)



Where in the code will I find this? I've looked through quickly and I'll dig some more, but guidance would be appreciated.


Thanks,
Braden]]> Braden Kear Controllers Mon, 26 Jul 2010 02:14:13 -0400 https://reprap.org/forum/read.php?13,52497,52836#msg-52836 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52836#msg-52836 DanielG Controllers Sun, 25 Jul 2010 04:43:09 -0400 https://reprap.org/forum/read.php?13,52497,52758#msg-52758 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52758#msg-52758 ANY help at all will be welcomed!
Dan]]> DanielG Controllers Sat, 24 Jul 2010 04:53:33 -0400 https://reprap.org/forum/read.php?13,52497,52743#msg-52743 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52743#msg-52743 here is something that I tried today that seems to work pretty well- in the stepping sequence code of the extruder I commented out the even number steps and left the odd numbers (so the ones that have pwm>>1 + pwm>>3 are active)

this allowed me to get a more consistent strength from the stepper motor and kept the heat coming out of the h-bridges to a more manageable level. no more thermal shutdown type problems while maintaining some strength.]]> lunchtrayrider Controllers Sat, 24 Jul 2010 02:55:46 -0400 https://reprap.org/forum/read.php?13,52497,52699#msg-52699 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52699#msg-52699 lunchtrayrider Controllers Fri, 23 Jul 2010 14:44:07 -0400 https://reprap.org/forum/read.php?13,52497,52692#msg-52692 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52692#msg-52692

]]> gr0k Controllers Fri, 23 Jul 2010 13:11:42 -0400 https://reprap.org/forum/read.php?13,52497,52691#msg-52691 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52691#msg-52691 lunchtrayrider Controllers Fri, 23 Jul 2010 12:49:44 -0400 https://reprap.org/forum/read.php?13,52497,52630#msg-52630 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52630#msg-52630 Triffid_Hunter Controllers Fri, 23 Jul 2010 02:07:51 -0400 https://reprap.org/forum/read.php?13,52497,52628#msg-52628 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52628#msg-52628 gr0k Controllers Fri, 23 Jul 2010 01:51:52 -0400 https://reprap.org/forum/read.php?13,52497,52625#msg-52625 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52625#msg-52625

Extruder0_ExtrusionPWM -1 does not show up in my host software. (most recent release) which release(s) is it in and is it not needed anymore?]]> lunchtrayrider Controllers Fri, 23 Jul 2010 00:16:46 -0400 https://reprap.org/forum/read.php?13,52497,52565#msg-52565 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52565#msg-52565
... i've checked - the A3949 don't have a power reducing mode as most other stepper drivers, only SLEEP, but then he's really down ...]]> VDX Controllers Thu, 22 Jul 2010 15:17:30 -0400 https://reprap.org/forum/read.php?13,52497,52563#msg-52563 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52563#msg-52563
gr0k, Extruder0_ExtrusionPWM is set to -1, the A3949 chips get warm to the touch after being powered up for a while, but not hot.


Thanks for the help so far

Braden]]> Braden Kear Controllers Thu, 22 Jul 2010 15:06:57 -0400 https://reprap.org/forum/read.php?13,52497,52514#msg-52514 Re: Stepper extruder looses torque https://reprap.org/forum/read.php?13,52497,52514#msg-52514 gr0k Controllers Thu, 22 Jul 2010 09:47:52 -0400