hello world, greetings from belgium

i started building a prusa a few months ago, and now it's ready for as far as i can make it ready,
but off course as with all great electronics, it doesn't work directly.

i'll start with saying what i have:
[www.crankbmx.com]
prusa mendel with plastic from nophead and gen 3 electronics from someone from poland (ebay.pl)
all other parts come from the hardware shop or mendel-parts (this is why it took me 2 months more to build)
i use the reprap software on a small net top pc with XP (1,6 ghz and 1Gb mem).

this is what works:
x-axis: the endstop works, the motor makes a buzz sound and wiggles but doesn't rotate when i move it in the software
y-axis: everything works perfect
z-axis: same as the x-axis
extruder: theristor and heater work perfect, the motor has a high pinched noise and wiggles a bit all the time. doesn't rotate.

things i have tested already:
-changed all parts with the Y-axis parts, and there everything works, so it's not a problem with a part i think.
-i put flags on the motors to see if they turn without any payload (no luck)
-looked at it for a very long time (hey, you never know it might work?)

what else do you need to know to help me, or can you already give me some tips?
thanks,

pieter

I'm no expert, but have you checked the amp adjustment on the stepper driver boards? It is a little potentiometer on the driver board. Try turning it up a bit at a time. Though I wasn't quite sure what you meant by "changed all parts with Y axis" If the driver boards all work when connected up to the Y axis control on the motherboard, then you are right, it's not hardware, unless it's the motherboard. Did you try swapping cables? That is a higher failure rate part than electronics. In the event that you've tried all that, it is likely a software issue. You should probably post the firmware version and any special configurations you are running and then better minds than mine can give suggestions.

Bryan

You say you are using Gen3 electronics? Are you one of those unfortunate souls trying to drive the extruder stepper from the h -bridges on the extruder controller instead of from a proper stpper driver like the rest of the axises?

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I'm building it with Baling Wire

i switched the cables as well. and tried changing the resistor value
the gen3 boards came with firmware loaded:
[cgi.benl.ebay.be]

as for software, i didn't change a thing apart from letting the software now it needs com port 3

I've had this problem a few times! I don't think it's your electronics... but to make sure you can swap things around. Try isolating a suspect motor with a working driver and vice verse till you have narrowed it down to specific parts... but here's the important part, you have to count the connects/wiring as suspect components. I think you have a short between your 2 coils on the stepper. This can happen when you have a 6 wire stepper and you wrap up the common wires and forget about them and they short It can also happen at your connectors, you have some frayed wires touching. If that's not it, I would definitely look at the trim pots... don't connect or disonnect motors or adjust pots with power on.

hello world, greetings from belgium

Need a forum for Belgian devs?

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-Sebastien, RepRap.org library gnome.

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Remember, you're all RepRap developers (once you've joined the super-secret developer mailing list), and the wiki, RepRap.org, [reprap.org] is for everyone and everything!

so i did some more testing and changing everything, and i think the problem is going to be located in my stepper drivers.

when i test them without motors, they all work perfect (as in the motor leds light up the same way when i send a move command, no mather where i place the driver)

the thing changes when i add a motor, then only the Y-board lets the motor turn, the other 2 let the motor buzz a bit (you feel it try's to turn)

so i inspected the 3 boards(gen3 ver 2.3) a bit more and found that the Y-board has different C10 & C11 capacitors.
the ones on the y- board say:
#8HN
100
50V

the 2 other boards say:
100
VTA
4D8

it's a wild guess but could this have anything to do with it?
pieter

did you try running your y board with the other motors?

and the other boards with the y motor and cables?

did you try adjusting the potentiometers?

Anthong Redbeard Wrote:
-------------------------------------------------------
> did you try running your y board with the other
> motors?
> yes, all motors run perfect then.
> and the other boards with the y motor and cables?
> yes, then the motors don't trun, but wiggle a bit.
> did you try adjusting the potentiometers?
yes, everything stays the same.

Have you tried swapping your stepper motor controllers? Since the Y works, try plugging the other two into the Y connector in the motherboard. This would confirm if it's the stepper controllers or the motherboard/firmware.

i swapped the others in the Y-port and they don't do the motor turn, but the Y-stepper in any other port does work.
this is how i now know the problem is with those stepper drivers.

my main problem is that the stepper work "a little bit" since they try to make the motors move.
this is what trouble's me, it would be easier if they didn't work at all.

anyone know if it could be those capacitors?

Found it!
well, it ended up being what i toughed it was, those capacitors are wrong.
i mailed the guy who i bought it from, and he said another customer had the same problem,
so my boards are back to Poland for replacement
so make sure they say 100-50v and not something else.
pieter

Hey!
I just found out that you're talking about electronics that I was selling :-)
Well, yes, I just tested those drivers, and it's strange... but after re-soldering all small capacitors (ceramic ones) and legs of allegro chips, both boards started working! So it was just a cold joint somewhere.
At first I also thought this is a matter of those big electrolytic capacitors, but apparently they're good...
Unfortunately your case was one of those 'Barebone' sets that I was selling, where stepper drivers were not tested (I am not selling them any more).
Anyway, they're ok now, and about to be sent back to you! :-)
happy repRapping!
cheers
Przemek
PS. Photos of boards working attached.

possenier Wrote:
-------------------------------------------------------
> Found it!
> well, it ended up being what i toughed it was,
> those capacitors are wrong.
> i mailed the guy who i bought it from, and he said
> another customer had the same problem,
> so my boards are back to Poland for replacement
> so make sure they say 100-50v and not something
> else.
> pieter

Edited 1 time(s). Last edit at 04/12/2011 03:36AM by jawor.