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Newbie Z Axis Issue?

Posted by urable2

urable2

Newbie Z Axis Issue?
September 18, 2014 11:54AM

Registered: 12 years ago
Posts: 14

I have recently finished putting together a prusa mendel i2. I get motor jitter(z axis) when both are connected to ramps but with one connected it moves fine. I am using a 12v 20a power supply. My question is, is it a power, ramps or motor issue? It is very frustrating. Any help will be very appreciated.

Thanks,

Keith

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Anonymous User

Re: Newbie Z Axis Issue?
September 18, 2014 04:12PM

Are the Z axis motors connected in parallel or series? If in parallel, it's a power issue and you need to up the vref.

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urable2

Re: Newbie Z Axis Issue?
September 18, 2014 09:58PM

Registered: 12 years ago
Posts: 14

Thanks a lot for the info. They are in parallel. My motors are rated at .6 amps. How do I set the amps correctly on the potentiometer? Also is there a way to check the current with a multimeter?

Thanks again.

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Anonymous User

Re: Newbie Z Axis Issue?
September 19, 2014 03:05AM

Here's the reprap wiki page for a4988 pololus. Make sure your drivers are pololus and not stepsticks, though, as the vref will be different.

Basically, plug your board into your PC and check the voltage on the board with positive on the pot and negative on one of the negative terminals on the RAMPS.