Extruder stepper Question... TechZone-Remix [solved] *Added Pics..

I'v been trying to test my rxtruder stepper motor.... in the reprap host software when i click extrude the motor starts... but when i click it again it does not stop...(edit: even if i don't click extrude again, it keeps running) is this normal? also the motor does not run steadily and the extruder board glitches out sometimes(like it resets)... is this also normal?

the only way i can get the stepper motor to stop is by resetting the extruder board...

Motherboard : V1.2 TechZone
Extruder board : v2.2 TechZone

Edited 6 time(s). Last edit at 05/16/2010 02:45AM by Mdbaughman2.

I don't use any of the RepRap software or firmware, so I don't know how it behaves but is doesn't seem right that you can't stop the extruder or that it does not rotate at a constant speed.

Have you connected the step and direction signals between the motherboard and the extruder controller correctly? The motherboard pulses the step signal to move the extruder and the extruder controller acts on it and updates the motor phase. If it is not stepping regularly and does not stop it implies that the step signal is not correct. Perhaps it is floating so steps randomly as soon as the extruder controller is enabled. A bad ground between the two boards could also allow noise to corrupt the step signal.

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[www.hydraraptor.blogspot.com]

What i did was i used a cd-rom analog audio cable for my i2c signal... using a small screw driver, i was able to remove the pins from the connectors and re-arranged them to my needs leaving the ground pins loose so i could connect them to the ground pins on the boards...





on the motherboard i also soldered a strand of wire to the bottom of the motherboard to use as a ground, to ground to my PSU.




I used the ground from the jtag as shield for the i2c cable on the motherboard... Note that i put some electrical tape on the ground pins of the cable so it would not make contact to any adjoining pins when connected...




on the extruder side i connected the ground shield to the ground pin on D9...


so basically i have now grounded my motherboard to the power-supply via (1) the wire i soldered on... and (2) the ground shield that comes from the the extruder board...


that seems to of fixed my problem!!! thanks Nophead!!!! I hope it helps someone!!!

Edited 4 time(s). Last edit at 05/17/2010 10:12PM by Mdbaughman2.

Yes all the boards should both have a short and solid connection to the PSU ground and hence be closely coupled ground wise.

When used as originally configured for Makerbot this is the case, but when modified for Mendel the motherboard is no longer connected to the PSU, so it gets it ground via the ribbon cables to the other boards. This is not ideal, especially if the extruder controller is mounted remote from the other boards.

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[www.hydraraptor.blogspot.com]

NopeHead,
I finally got around to uploading the pics you asked for... Hope it helps sombody!!! oh here's a pic of my mendel... Its only lacking a geared extruder... I'm planning on adding a stepper driver board to drive the extruder... it will be 1/2 stepping and silent! I already tested it!!! (I had to check if it was working, because i couldn't hear it!

Thank you Mdbaughman2 for the pictures and your work on the how-to faq. I find it very helpful as I just received my electronic set, and am just now wiring it together. Is it a good idea to solder the grounding modification anyway, even before testing the boards, just to be sure? Or would it be enough to add the cd-rom audio cable to start with?

I made a illustration of where all the ground points are, but before posting it to the wiki, I'd love a second opinion to verify that the markings are correct.

(The plate is designed by Azdle.)

Just a few more notes about my experience so far, while I'm at it:

The supplied 10-wire ribbon cable only had 9 wires, but I used an old IDE cable instead. It works fine since I have the electronics close together, but it might be too short if you mount the electronics like on the official mendel.

I didn't feel I got the hang of making proper connections with the supplied plugs. So until I find the right tools to make my own plugs, I cut off a bunch of floppy molex connectors from some old PSUs to use with the opto endstops. For the USB-TTL I used the brilliant jumper trick.

Edited 1 time(s). Last edit at 06/18/2010 10:52AM by Nudel.

After looking over your pic... everything looks right! i'm glad to hear the pages helped...

due to how busy i've been doing concerts... (i'm a sound/lighting engineer) I haven't had time to finish the "How To" page.... so I'm looking anyone who could help finish the How to page that I started for other Techzone users... really this is for techzone users... so i think it would be appropriate to let my fellow users finish it.. i do have a lot of the drafts done, and i'm sure there are other users who have some really good ideas that they would like to add to the the page...

so since i haven't had time to finish it... i invite/urge the community to help out!

cheers MB

Edited 1 time(s). Last edit at 06/18/2010 11:08AM by Mdbaughman2.

Oh, Nudel... Thanks for the FAQ!

You're welcome. Added a little information here and there, and updated some pictures.
I feel I need to have my set working before I can add much more information though.