Volts at torch way too low

[ajk2004]

Hey Guys,
I am new to the CNC world. I built my own table and bought the C and CNC bladerunner and I have a new HT 65. I have watched several vids online and feel confident enough in sheetcam and mach 3. I am just doing some test cuts and I have a question about my screen in mach and the cuts. I am having a difficult time making good cuts on metal. I am cutting 11 ga metal to test with. I have the feed at about 120ipm. The pierce delay is .5 seconds. The preset volts are 85. That is what the manual says. When I cut, the window on Mach 3 only reads at most, about 20 volts at the torch. If that number was at 85 or close to, I'm guessing my cuts would be much better. The mechanics of the machine look good. I get straight lines and circles, but the torch isn't cutting cleanly around the objects. I am a school teacher and we got a torchmate a couple of years ago. I'm not too impressed with it so I built my own machine. This machine will run circles around the torchmate but the software is a much steeper learning curve then torchmate CAD. With that being said, I think the possibilities are endless with inkscape or corel draw as opposed to TMCAD. Please help as I have no idea how to remedy this situation. The piece I am working on is probably 10" x 36" and I have the ground clamp on the piece I am cutting. I have a water table but no water in it currently as I am only in testing mode. Thanks for the help.
Andy

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[trtilton61]

Is your pwm sensor module and your rav divider set to the same ratio. The raw arc voltage divider on the pm 65 usually comes set at 50:1. Candcnc's rav card is 7:1.

[ajk2004]

Trtilton61,
Thanks for the reply. Is there an easy way to change that. I'm not sure where I would find that on my manual. I will take a look. Thanks.
Andy

[ajk2004]

I found it in the manual but I'm not sure I understand. There is a statement in the C and CNC manual that says, "The hypertherm document has additional switch settings for other divider ratios but ONLY the 20:1 OR 50:1 ratio work the the DTHCIV." I have the PWM sensor and it is sent from the factory at 7:1. So, shouldn't this work? Thanks.
Andy

[ajk2004]

I even took the cover off of my plasma to verify it is either 20:1 or 50:1 and it is 50:1. So now I am still lost as to why my torch volts during a cut are super low...

[acourtjester]

Have you tried the button on the back of the Sensor PWM that sends a test signal which shows on the Mach screen as 125 or 126 volts?

[ajk2004]

Acourtjester,
Thank you for your suggestion. I just did that and I got 125 volts on the Mach screen. It felt good to see a high number. What does this tell you? I get a sufficient number on the test but when I run the torch I only get about 20 volts. My consumables are newer. I have only been using these to test on so they haven't done much cutting. I think the voltage is the main problem. I am using 45A finecut consumables. The feed on those is 120ipm. When I run 45 amps on the plasma cutter at 120 ipm, it seems much too fast, like I don't have enough power at the metal. Thanks.
Andy

[sphurley]

Look on the back of the PWM. That is where you change the PWM ratio to match what you have the Hypertherm at.

[sphurley]

NewPWM.pdf

Here is what a newer model looks like

[ajk2004]

Sphurley. I saw that on the back. I don't know what it's called but do I take the clip off of the 7:1 pin and put them on the 50:1 pin? Thanks.
Andy

[WyoGreen]

Yes, you match the PWM setting to the plasma cutter setting.

Steve

[BTA Plasma]

Do yourself a favor and Go to Config/toolpath and uncheck 'show machine boundaries'. This way your geometry fills the screen