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

  Thanks Rod,

I have used 7/8 - enc, 9 - gnd, 12 - 5v+

Should i change to 6 for 5v+ ??

No, 7I96 TB2 pin 12 is the correct 5V source.

What are the scaling factors that you used?
(there must be a missing hal file  where plasma voltage scaling/offset is done)

scale = 0.00779537
offset = 3637.5

PCW wrote:

No, 7I96 TB2 pin 12 is the correct 5V source.

What are the scaling factors that you used?
(there must be a missing hal file  where plasma voltage scaling/offset is done)

QTplasmac stores the THCAD scaling settings in the GUI as per the previous screen dump the OP shared.

I’m sure it’s something very simple that I have got wrong. 

last night I realised that I don’t have an arc ok showing when the torch fires. Checked wiring and it’s all correct. 
Cpc pin 12 goes to input 10 on the Mesa, pin 14 goes to common +. 

The approximately +- 15000 encoder velocity numbers in the video
seem like pure noise. (and negative values should not even be possible)

I would first try jumpering the 'B' input as single ended and see if that helps
(also make sure nothing is wired to either 'B' input)

Do you get steady arc voltage readings when the plasma supply is off?