Troubleshooting

[nighthawkFmobil]

So im really happy with my DIY TouchDro build i did for my pm940 mill with vevor glass scales but ive been running my Yaxis scale from the W connection because whenever i plug it into the Y connection the numbers will jog about 4-6ten thousandths after stopping the table. For instance if i stop at 1" it will jog to 1.0004-6"and it only does it it one direction. Its only the Y axis. I can plug my Y scale into any other port and it will work fine. If i plug my x or z scales into my Y port it does the same thing and jogs. The X,Z and W inputs are super accurate and work as they should.

I've looked over my soldering with a microscope and cant find any bad connections. I reflowed the solder from my Y output pins going into the resistor network and that didnt help. I have my resistor network in the pulldown configuration. Hoping someone can give me a hint. Its fine to use it like this for now but id like to get a scale for my quill so i can integrate that into my z reading and ill need all 4 connections at that point.

Thanks

 

[ycroosh]

Hm, I haven't heard this one before. 4-6 tenths is about 10 micron, which is two "steps" or 1/2 of the quadrature wave of a 5-micron scale. The only thing I can think of is that there is a spurious edge. I.e. the signal on one of the lines (A or B) goes from low to high or vice versa after you stopped moving. I wonder if you have a blown resistor in the resistor network that is leaving one pin floating.

I don't think it's in the MCU. That firmware is years-old, so it's been very well debugged at this point. It could be a silicone problem, but its too weird for that.

Regards
Yuriy