interface/driver board x y problem

[edmond22]

Hi all
I am having a few issues with the interface/driver board rev 2.1 i got from Bart last year, the y axis doesn't function and the x axis motor runs rough and slow no matter what speed i set it to in mach 3. I have swapped the y and z around and it works fine, the x also works fine if i drive it off the z driver. I presume the x pololu driver is dead and maybe the y one also faulty, can i test these somehow with a multimeter. Also the pwm/pot relay clicks as soon as i apply power to the board and the front panel switch causes it to do nothing, have i wired it right or maybe soldered the relay the wrong way it, it looks right according to the photo of it on the instructions, the writing on the relay runs from L to R looking at the board from the DB25 connector side.

Any help or suggestions pls.

If its the pololu stepper drivers then im stuffed as they are not available locally in SA

[BenJackson]

"Rough and slow" could be two things:

1) Loose connection to one of the motor phases. The motor will also move backwards sometimes.

2) Overheating driver. It has thermal protection so it will cut in and out very fast. The axis will move but it will have no torque. Everything will work fine when you first turn it on (and things are cold) for a few moments.

[edmond22]

Thanks, I will check those 2 suggestions tonight, but the X and Y motors work fine when tested on the Z driver so I can rule out loose motor connections, but how can I sort out an overheating issue, the heatsinks on the Y and Z chip feel warm to touch but the X one gets hot really quick

I noticed the X pololu driver gets hot very quick, I can smell it a few seconds after the board is powered up, I am running the small 5v fan that Bart provides with the board.

[BenJackson]

The chips are rated for 1A with no heatsink. However, they ship from the factory set much higher and with no heatsink. I now run with Bart's fan, no heatsink, and 1A current setting.

Look at the tiny pots on each board and see if your X is turned up higher.

[edmond22]

I played around a bit with the board, managed to fix the pwm/pot relay issue, I had wired the front interface panel up wrong as I used a male 9pin connector for J2 on the board instead of the correct female connector so thats all good now.

Driver chip current settings are set up at 0.24V as my motors are running in bipolar series at 0.6A.

I did notice if I play around with the steps/mm setting in Mach 3 I can get the motors to really move it, I think its a Mach 3 issue or a steps/mm issue steps/mm is set at 39.37 as I work in mm and not the 1000steps/inch.
I did notice that Mach3 somehow is limiting the rapid speed to 600mm/min instead of the 6000mm/min I set it at.
If I set the steps/mm to 393.7steps/mm I can get the full 6000mm/min rapid speed but then the motor moves 10x the distance it should, im doing something wrong but what?

[edmond22]

I managed to get all 3 axis working, I just turned the current setting pots to minimum and started all over, this time making sure they were all adjusted to 0.24V.

The interface/driver board is working 100% now, fantastic all in one solution.

I must have set them wrong in the beginning, it was 12am in the morning when I set them the other night/morning and I probably misread the multimeter.

Mach3 is still only moving my motors at 10% of the velocity I set them at so I set them at 60000mm/min and they move at 6000mm/min as shown in the feedrate display in Mach3

[Greolt]

Mach3 is still only moving my motors at 10% of the velocity I set them at so I set them at 60000mm/min and they move at 6000mm/min as shown in the feedrate display in Mach3

Sounds like you have the jog speed set to 10%. Go to the jog control screen and set it to 100% (tab)

Greolt

[edmond22]

Thanks Greolt, that was the issue I hit the Tab key and the jog screen popped right up and it was set at 10% of the jog speed I suppose its a default setting.