Author Topic: Pokeys, mach4 no go?!  (Read 1376 times)

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Offline oddname

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Pokeys, mach4 no go?!
« on: October 10, 2018, 01:25:39 AM »
To make a long story short(er). It started when I wash hooking up the basic things needed to get my oxcnc moving.

Started with this;  https://www.youtube.com/watch?v=9u8CvoVQZXc   very odd movement, same with pendant or no pendant, it doesnt move cleanly.
Checked other axis, they wont allmost budge, but they are easy to move by hand.

Then I checked further, removed all things keeping a load on the steppers, this is what happens now
https://www.youtube.com/watch?v=Cdbz5dgRhq0  https://www.youtube.com/watch?v=z5oYCf9BRnY


Checked drivers, tried 1/2-1/4 Microstepping.

Thought maybe I did a booboo on the cables, but A+ A- B+ B- seems to connect to where they should
So I checked the motion controller > driver cabling, A Ok there aswell, connected as shown on diagram  + alarm,  




not sure if wiring this wrong might give me the erors I am having, as a final trial I will be making new basic cables just like this diagram.  



Any other final ideas would be awesome :)

Offline joeaverage

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Re: Pokeys, mach4 no go?!
« Reply #1 on: October 10, 2018, 02:07:53 AM »
Hi,
from the sound of the stepper on your video I would have guessed that the signaling current to the stepper drive is
marginal/not enough. Can you put an ammeter in the DIR line and establish what the signaling current is?. From the specs
it should be at least 10mA.

Craig
My wife left with my best friend...
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Offline oddname

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Re: Pokeys, mach4 no go?!
« Reply #2 on: October 10, 2018, 02:40:43 AM »
Does a multimeter work for this?

Just measure pin to gnd when trying to move?

Offline joeaverage

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Re: Pokeys, mach4 no go?!
« Reply #3 on: October 10, 2018, 02:55:11 AM »
Hi,
no, that measures voltage, you want to know the current.....current s responsible for the photodiodes light output
in the drives optocoupler. With insufficient current the light output decreases markedly then the phototransistor
won't switch or saturate like it should.

If your multimeter has a DC current measurement range, that would work. Remember when your multimeter is in current measuring
mode your probes are almost shorted together....if you forget and try to measure the supply voltage to earth say then you'll pop something.

Craig
My wife left with my best friend...
     and I miss him!

Offline oddname

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Re: Pokeys, mach4 no go?!
« Reply #4 on: October 10, 2018, 03:11:29 AM »
I have never measured current before, but the MM can do it.

So just insert the MM in between the connection, should I just leave the driver connected and put the MM in the circuit between them then?

Offline joeaverage

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Re: Pokeys, mach4 no go?!
« Reply #5 on: October 10, 2018, 04:24:14 AM »
Hi,
no, you have to remove the normal connection and replace it with the multimeter circuit.

In current mode you might think of the multimeter as 'a bit of wire with a probe at each end'. It just so happens that the 'box of tricks'
the current passes through measures and displays the current.

Craig
My wife left with my best friend...
     and I miss him!

Offline oddname

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Re: Pokeys, mach4 no go?!
« Reply #6 on: October 10, 2018, 05:15:57 AM »
Yeah I was a bit unclear, I should think of the MM as the wire between pokeys and driver in the circuit for the Dir pin.

Any other ideas on what could be wrong?  I havent connected anything wrong considering i checked pins, nothing that should damage anything atleast.

Polabs recommend Dir+ Step+ of my driver to the signal pins on the pokeys and the negative ones to gnd (My driver has both Dir+ Dir - etc, currently my + pins are fed 5v and negative = connected to signal of the pokeys.    Maybe this will help out, not sure though yet :)  Cablestuff on the mail, but I can make a quick rework of an old cable to test.

Thinking about it, 5v to the signalpin ins on the driver and then signal aswell from the pokeys to negative pins, cause of issue?
This could also explain the sound when enabling the drivers, sounds like a screeching noise and then holds torque as should, this could be a lead!
« Last Edit: October 10, 2018, 05:18:55 AM by oddname »

Offline joeaverage

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Re: Pokeys, mach4 no go?!
« Reply #7 on: October 10, 2018, 01:38:10 PM »
Hi,
if you measure the current in the DIR circuit you will establish whether the logic you have used to wire the pins is
correct. Have you measured the current?

Craig
My wife left with my best friend...
     and I miss him!

Offline oddname

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Re: Pokeys, mach4 no go?!
« Reply #8 on: October 10, 2018, 01:49:31 PM »
I havent measured but I did connect now as polabs suggested, in contact with support there aswell, but still the same problem, less crunching if I unplug the encoder, but I think it is just deciding if the "twitch" when enabling is movement that shouldnt be there so it compensates.

But all in all still no motion.

Offline joeaverage

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Re: Pokeys, mach4 no go?!
« Reply #9 on: October 10, 2018, 02:08:17 PM »
Hi,
MEASURE THE CURRENT!!!! If you don't know what current is exciting the photodiodes you don't know whether they
are working.

Craig
My wife left with my best friend...
     and I miss him!