Homemade CNC Plasma - hypertherm, Mesa, gear drives, nema 34.

Halshow has the reading fluctuating from about -3650 -> +3650 with no plasma source having power.

in linuxcnc, the arc reading sits at -29

Jumping the B input?

Confirmed - mesa i/o pin 10 is lighting up when I should get an arc-ok input from the plasma, but linuxcnc isn't showing this.

Current codes

 

>Halshow has the reading fluctuating from about -3650 -> +3650 with no plasma source having power.
you have a 0 volt frequency of 3637 in you system so 3650 is expected. The swings are not
There is something not right in hal, like you have a double ended encoder or something.

+- velocity values are not possible in counter mode unless you have noise on the "B" input

Try jumpering the "B" input for single ended mode
(and make sure nothing is connected to either "B" input at TB2)

 

Thanks PCW.

Yes, I had the Ohmic sensing into the B encoder input on TB2.

Once this was unpluged, Encoder velocity stayed at 0. or flucuated to -3750.

Grounded everything i could and moved plasma source 30cm further away.

And hey presto.





 

Yes, I had the Ohmic sensing into the B encoder input on TB2.

That's OK with 7i96dpl.bit firmware (that has three separate encoder 'A' pins)

Thanks PCW.

I'll try an reconnect the ohmic to a different encoder A pin.

Also need to work on the air scribe next.