esab ultrarex retro fit plasma / flame cutter

hi again im wanting to retro fit the above machine and think it should go all smoothly (the control has died buy the way just seams sensible to upgrade and not just replace )

was going to use a 5I20 with 7I33TA and 7I37TA (the servo dirves are built in the head and on the gantry motors)

and aslo would like to upgrade too voltage sensed hight control the machine currently has a capacitance sensed hight control and is driven with a servo but it has no feedback ie encoder or such as the initial hight set would be for the pierce only could i not just fit a touch-off switch and then Z up for a timed bit to set pierce hight then let thc take over ?

many thanks john

to make it clearer a like to a vid of the machine and current hight control setup

hi john

as far as the electronic side of it im not sure as you see in the video it just seams to sense when near and object and this sensing range is on a pot of the control screen im not sure how i could interface this to emc however i would like to upgrade to voltage based control as it makes for a better square cut but would it mean making a new z axis or at least making it stepper drive.

or would i say get away with the fitting of a probe to touch off and then almost guess as too how far to back off for the pierce and then switch to the volage reading as it would normally

is there an axis interface already set up for plasma john ? ie with an input box for the requested cutting volts, pierce delay time and pierce hight settings ?

thanks john

any encoder supplers you would reccomend?

Not an encoder recommendation but I would be sure to get a
encoder with differential outputs (line driver or RS-422 type)
as the encoder is in a electrically noisy location