more Ohmic issues

[DanGeorgian]

everything was fine yesterday. wasnt getting ohmic reading today so tried just setting heights and the torch buried itsself (for some reason the sample voltage shot down to 120 and it buried) so for the sake of time i just went back to ohmic sensing. still nothing. cleaned all the consumables, cleaned the material surface at point of contact and at ground, jiggled all my connections, shut everything down and checked fuses, once restarted, still no ohmic.

also my 3/8 plate has no warp or anything like that. why did the sample voltage drop so low as to cause the torch to touch? i have to set it to 140 for the begining and it pretty much hovers around 139. any less and its too close to the material and causes other issues.

 

[Dnmeistr-LECS]

You can increase the sensing delay for Sample Voltage, under Machine Settings increase the Distance to Corner value from .5 to 1.0, this may result in a more accurate reading to allow the voltage to settle down before capturing it.

As for Ohmic, turn the Relay on under Machine Settings - Advanced Tab, jump the orange wire to the VFC ground wire, check for Ohmic detection. Then go from orange wire to a slat support and check again, then from orange wire to the material. If detection happens at VFC ground wire but not slat support or material then you have to much resistance, between VFC ground and the table.

 

[DanGeorgian]

got it. for everyone elses trouble shooting..... someone in the shop dragged an air hose over the table and it knocked the torch head off the gantry at the break aways. When the torch head fell off it landed on the clip that touches the ohmic cap. causing a dent in the ohmic cap right where the clip makes contact. swapped out the ohmic cap and shes good again.

 

[DanGeorgian]

Thx Dnmeister. ya i was checking for continuity between things and found i had connection all the way to the cap. i saw the dent when i was cleaning stuff but i didnt think to correlate the two things.

 

[Dnmeistr-LECS]

Sometimes just a slight untwist of the shield cap will fix that as well, as you will get some corrosion between the cap and the clip.

 

[Kchoghead]

once in a while i pull the shield off ant lightly sand with emery cloth....works like a charm for ohmic