A4988 drivers... Dead?

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Stabilitronas
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Joined: Sun Mar 17, 2013 11:48 am

A4988 drivers... Dead?

Post by Stabilitronas » Sun Mar 17, 2013 11:58 am

Hello everyone,

so, I was assembling my eShapeOko electronics: adjusted vref, connected motors and 24V power supply. They were working normally, turning in both directions. Then I decided to add jumpers for microstepping, and... That's it. Suddenly everything stopped working. I see signals coming from Arduino, but the output is pretty much constant. Motors are very hot, drivers too. So... Should I order new drivers or the problem may be somewhere else?..

ejs
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Location: Pittsburgh, PA, USA
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Re: A4988 drivers... Dead?

Post by ejs » Mon Mar 18, 2013 1:51 am

They're likely kaput. They're a great, compact, and inexpensive way to get steppers stepping, but they are also sensitive.

Vref is the only change you should be making while the boards are powered up. Don't connect, disconnect or change anything else, including jumpers, while powered up.

The other possibility is that you didn't alter your GRBL settings to match the new number of steps. Motors being stepped or microstepped too fast can stall. Check these numbers and try dialing your default seek rate way back before trying again.

If they are dead, I carry these in my store and my shipping costs on small orders are more reasonable than ordering from Pololu.

~EJ
Build it better than it was built for you. And give permission for the next guy to do the same. That's how Open Source works.
ShapeOko # 497: http://bit.ly/reactshop producing the Buildlog CNC Stepper Shield

Stabilitronas
Posts: 2
Joined: Sun Mar 17, 2013 11:48 am

Re: A4988 drivers... Dead?

Post by Stabilitronas » Wed Mar 20, 2013 6:20 pm

Hah. Today I received my new driver chips, resoldered one module, and guess what? It wasn't working.

Then I reflashed Arduino board, and changed some "$" parameters. And now it's working! Even the old drivers! Hell knows what has happened. Perhaps static discharges corrupted the flash or... I don't know what.

I've now got 5 spare drivers :)

ejs
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Joined: Sat Apr 28, 2012 7:42 pm
Location: Pittsburgh, PA, USA
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Re: A4988 drivers... Dead?

Post by ejs » Wed Mar 20, 2013 10:09 pm

That's...nuts. But good! Glad it's doing what it's supposed to. I hope you never need your spares 8-)
Build it better than it was built for you. And give permission for the next guy to do the same. That's how Open Source works.
ShapeOko # 497: http://bit.ly/reactshop producing the Buildlog CNC Stepper Shield

cvoinescu
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Location: Camberley, UK
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Re: A4988 drivers... Dead?

Post by cvoinescu » Wed Mar 20, 2013 10:20 pm

I hope he needs the spares! 3-D printer extruder, second extruder, third extruder, rotary axis, pick-and-place part rotation (that's rotary axis C), and so on... one never has enough drivers. :D
Proud owner of ShapeOko #709, eShapeOko #0, and of store.amberspyglass.co.uk

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