1 Topic by labguy

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Topic: Extruder suddenly extrudes slow.

I've been running my SD2 for over a year now without issues. Today,  the extruder suddenly turns very slow. Normally it will extrude 5mm in a second or so. Now it takes 10s+. Here's what I know:


(1) Pronterface is set to 200 for extrusion rate.

(2) Rebooted computer and SD2 to make sure it wasn't confused.

(3) Verified X-Y-Z axis behave normal.

(4) Released spring/arm mechanism and removed the filament so motor doesn't have anything to push. Same behavior.

(5) I just noticed the fan on the extruder motor isn't running and is hot to the touch. I have no idea how long it's been like that.

(6) I shut everything off, put an external fan on motor to cool it, after cold to touch, restarted, heated it back up. Same problem.

My current thought is the fan is shorted and drawing too much current so the extruder motor doesn't turn properly. I want to disconnect the fan to see if this is true. Does anyone know which connector to the motherboard is for the fan? I searched but couldn't get an answer. Any other ideas?

Thank you for the help.

Jeff

2 Reply by 3d-oodler

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Re: Extruder suddenly extrudes slow.

This sounds similar to what happened with my Y stepper.  I ruled out the motor itself, the stepper driver, the ATMega chip, the stepper resistor and capacitor on the board, but in the end I needed to replace the board.  Hopefully that's not the case for you, but you could try the same troubleshooting steps (for starters maybe attach your "E" (extruder wirelead) to say the "Z" stepper slot on the board.  Then try and move Z UP/DOWN to see if the extruder motor moves equally slow or not.

As for the fan, I believe it's the bottom left white 2-pin connector marked "F".

http://www.solidoodle.com/wp-content/uploads/2012/01/Motherboard.jpg

3 Reply by labguy

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Re: Extruder suddenly extrudes slow.

I really appreciate the detailed information. Looks like it's a board-level problem. Here's what I did:


(1) Pulled the fan and tested again. Same slow extruder problem.

(2) Checked fan voltage out on board. +12V.

(3) I powered the fan with a bench supply. It worked.
I plugged it back into the board, and now it works. I think the fan may have never worked and was put in with reverse polarity at the factory. It's a bit noisy which leads me to think the bearings are bad. Separate issue for now.

(4) I swapped E with Z (brilliant idea BTW). Sure enough, the extruder motor works fine, and now Z is slow and intermittent.

(5) I carefully inspected the top surface of the board and didn't see any obvious damage.


So, should I just get another board or do you have other thoughts on what else I should look at?


Jeff

4 Reply by IanJohnson

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Re: Extruder suddenly extrudes slow.

Check the Vref on that stepper driver to see if it is giving the motor the correct amount of current - http://wiki.solidoodle.com/multimeter-testing. 

If it is, then it sounds like the driver is bad.  If you get a new driver for the extruder, go for one with 1/32 microstepping like this one - http://www.panucatt.com/product_p/sd8825.htm

5 Reply by 3d-oodler

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Re: Extruder suddenly extrudes slow.

You can swap the stepper drivers to rule that out.

You can also reassign the PINs in PINS.H to rule out the microcontroller.

Here's the thread from when I experienced the problem, and what I did to troubleshoot:
http://www.soliforum.com/topic/3600/y-stepper-crawling/

You can get a new Sanguino board from Geeetech for $27 +shipping (and reuse your stepper drivers assuming those are fine):
http://www.geeetech.com/reprap-sanguino … p-609.html

If you do go with an SD8825, you might also consider getting it from qu-bd.com:
http://store.qu-bd.com/product.php?id_product=55

A couple of us had a poor experience with panucatt.com (delayed shipping, poor communication).  I had a good experience with qu-bd.com.

6 Reply by 3d-oodler

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Re: Extruder suddenly extrudes slow.

BTW  I'm pretty sure that my board was fried due to shorting the extruder thermistor.  You should check that everything else is working OK before connecting a replacement board (others reported shorting their board due to contact with the casing or debris between the board and casing).

7 Reply by labguy

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Re: Extruder suddenly extrudes slow.

Thanks for the advice guys. Here's what I did:


(1) Bought a new driver, installed it in Extruder, set the Vref. Same result.

(2) Put new driver in for Z, set Vref. Works fine (verifies driver is ok).

(3) Measured Hot End resistance: 6.1 Ohms.

(4) Measured Thermistor resistance: 108 KOhms.


I have not ruled out the chip yet. Thoughts? Should I just buy another sanguinololu and move on?

If I do buy a sanguinololu board (assuming the chip is ok), I can just swap the chip and fire up the SD2, right?


Jeff

8 Reply by 3d-oodler

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Re: Extruder suddenly extrudes slow.

A new sanguino will likely come with a micro controller.

You'll need to move the stepper drivers over and apply the SD firmware.

It's easy enough to swap pins in the firmware, to rule out the microprocessor, and it will get you familiar with that process, if you are not already.  But I kind of doubt it's the atmega.

9 Reply by Hazer

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Re: Extruder suddenly extrudes slow.

labguy wrote:

Thanks for the advice guys. Here's what I did:


(1) Bought a new driver, installed it in Extruder, set the Vref. Same result.

(2) Put new driver in for Z, set Vref. Works fine (verifies driver is ok).

(3) Measured Hot End resistance: 6.1 Ohms.

(4) Measured Thermistor resistance: 108 KOhms.


I have not ruled out the chip yet. Thoughts? Should I just buy another sanguinololu and move on?

If I do buy a sanguinololu board (assuming the chip is ok), I can just swap the chip and fire up the SD2, right?


Jeff

Well, if its not the motor, and its not the driver, then you have the motherboard and the atmel left. I dont know how much the atmel costs alone, but since it is socketed it may be the cheaper way to check first. Problem is, you would have to buy one with the bootloader pre-installed.

Or you can get another sang board that will come with the processor and bootloader.

To answer your question: Yes, you can swap atmel chips and keep the original one with yuor firmware already configured. But if the atmel chip did lose its pin, then the problem will follow the chip. Either way, you should be able to confirm where the problem lies.

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10 Reply by labguy (edited by labguy 2013-10-31 04:39:28)

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Re: Extruder suddenly extrudes slow.

Sigh...still stuck with the slow (grinding) extruder port.

I went ahead and bought another Sanguino v1.3a board with the 644p installed ready to go. Swapped it out, uploaded the latest Marlin firmware (thanks for the video guide Ian). Connected:

(1) X, Y, Z behave normal.

(2) Heat up nozzle and try extruder: Same issue.

(3) Verify Vref on extruder: OK.

(4) Swapped Z and E cables and test. Extruder works fine, Z exhibits issue.

(5) Swap Z and E cables back. Swapped Z and E drivers. E exhibits behavior. Z is normal.

(6) Put Z driver back. Put in new driver for E. Set Vref. E exhibits behavior. Z is normal.

* Not the motor.
* Not the driver.
* Not the board (assuming new board is ok and I didn't hurt it).
* Not the chip (new).

Confused. What am I missing? Ideas?


Jeff

11 Reply by 3d-oodler

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Re: Extruder suddenly extrudes slow.

Hmmm... to isolate it have you tried disconnecting cables to the board one at a time?  Maybe a short somewhere.

Inspect your thermistor closely making sure the wires are not touching at the bead of glass (outside).

Same for other cables.

If you find a short it is possible the new board was impacted by it too.

12 Reply by ronsii

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Re: Extruder suddenly extrudes slow.

Are you sure it isn't software related? have you tried RH ? another thing to try is varying the extrusion rate 1mm/s, 5mm/s,20mm/s,250mm/s, etc... just to see how it affects the stepper as this could indicate where the problem is...

13 Reply by labguy

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Re: Extruder suddenly extrudes slow.

Solved!

ronsii, thank you for pushing me in the software direction! Turns out it was Pronterface:

(1) Installed Pronterface with same config on another mac, extruder worked normal.

(2) Went back to original mac with pronterface. Doesn't work.

(3) Installed RH on original mac. Worked.

I never considered the issue as a software problem because the behavior mimicked hardware issues other people were having. Oops. So, in short I should have first reinstalled the software and/or tried a different computer. Then investigated hardware issues.

I have no idea what went wrong with Pronterface on that machine. It is solely used for the SD2 and is very stable. At this point I don't care. I now have spare parts, the latest firmware, a fixed fan, and running RH. Bliss!

I greatly appreciate the support everyone provided.

Jeff