PT80 Ohmic Cap

[Mr.Hotwire]

Since I have an ohmic sensor on the way, and It doesn't look like there is an ohmic cap for the IPT torches commercially available.. what have you done to support this? I have been looking at the various caps and shields, there MAY be a way to make things work using a modified cap / shield combo.

[acourtjester]

There are videos on YouTube with different torches with a connection, not sure but think if you have a HV start you may not be able to use it. Some have used the Proximity sensors with place of an actual ohmic sensor (there are 2 types NPN and PNP).
https://www.youtube.com/watch?v=BnGWuX9zX0Q
https://www.youtube.com/watch?v=UzV6FR8RgOY

[adbuch]

There are videos on YouTube with different torches with a connection, not sure but think if you have a HV start you may not be able to use it. Some have used the Proximity sensors with place of an actual ohmic sensor (there are 2 types NPN and PNP).
https://www.youtube.com/watch?v=BnGWuX9zX0Q
https://www.youtube.com/watch?v=UzV6FR8RgOY

I'm not sure how having a High Voltage start would affect the process of ohmic sensing. The torch would lower until contact is made with the material thru the ohmic cap/shield, then raise to pierce height and fire the torch. Perhaps I am missing something here. I'm always willing to learn.
Thanks,
David

[djreiswig]

Some people have had issues with some cutters because the shield is internally connected to the work lead. This won't work because the tip and plate are always connected. Not sure what brand of cutter is like this, but it's something to check.

[adbuch]

Some people have had issues with some cutters because the shield is internally connected to the work lead. This won't work because the tip and plate are always connected. Not sure what brand of cutter is like this, but it's something to check.

Ok. That makes sense. Thanks for pointing that out. I suppose there might be a work-around by adding a separate ohmic probe not in contact with the shield. I think I remember seeing that done a while back. Or using a proximity sensor as described previously.
David

[Mr.Hotwire]

The highlighted parts are the ones needed for the PTM-80, FINDING them is the issue.

IPTM-80 Contact cut parts.PNG

IPTM-80 Contact cut part numbers.PNG

[adbuch]

I would recommend phoning Century Tool & Equipment to see if they can order them for you.
David

https://www.centurytool.net/PT_TORCH_PT ... 374783.htm

[djreiswig]

Here's the shield from a Missouri seller.
https://www.ebay.com/itm/324279630161
No luck on the cap.

[Mr.Hotwire]

I was able to get this working, AMAZINGLY. Very much like the caps that HT uses. Only I used a hose clamp with thumb screw and a terminal end soldered to it. Ill post pics of it up and running. I just wish I could get some 30-40a contact pips for this... But so far its cutting pretty f'n good. I just need to tune my SheetCAM path rules and clean up my post, and I will be off to the races.

[adbuch]

I was able to get this working, AMAZINGLY. Very much like the caps that HT uses. Only I used a hose clamp with thumb screw and a terminal end soldered to it. Ill post pics of it up and running. I just wish I could get some 30-40a contact pips for this... But so far its cutting pretty good. I just need to tune my SheetCAM path rules and clean up my post, and I will be off to the races.

Glad to hear you've got it going. DIY ohmic caps are pretty common with some of the off brand cutters. So you're not the only one who has had this problem.
David