DTHC Raising but not lowering

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BensPlasmaAu
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DTHC Raising but not lowering

Post by BensPlasmaAu »

As it says. Basically I was cutting 1.6mm mild steel and all the cuts worked really well. Then the last process was to cut the sign I had made out. It was 1190 x 490mm and started the cut well. It went around 1.5 sides and then on a long cut He torch started raising. It didn’t stop going up and I could do nothing to get it to come back down. What happens here? It has happened a few times before but I thought it might have been an operator error. Now it happened again I kind of th8nk it’s someth8ng in a setting or a card issue. If anyone has ideas, let me know. Cheer!
Home built 3400 x 1400mm (11 and a bit X a bit over 4.5 feet)
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Some air dryer off the internet
Another water seperator I found unused on a shelf
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motoguy
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Re: DTHC Raising but not lowering

Post by motoguy »

Sounds like Tip Saver. Make sure it's shut off. In Mach, I had to shut it off both in the Hub Admin, and in the Mach "flyout" screen (press the tab button).

I've got it shut off in CommandCNC as well, though I think it's just a check box in the DTHC settings.
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tcaudle
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Re: DTHC Raising but not lowering

Post by tcaudle »

A clue is if the Tip Saver Active Screen LED is on. That should never come on and stay on. It should just flash. It used to work pretty good when the old DTHC was using the MACH Up and DOwn. it was slow enough that it cold trip faster than the Z could move to correct. That is not the case with the DTHCIV that is 5 to 10 times faster. TIp saver detects a volatage spike and locks down motion but it the voltage nevers drops back down to normal it "locks" its self and will ratchet higher . The DTHCIV is faster than the Tip Saver! Either increase the tip saver % in the Cut Profiles or turn it off. If you get head diving setup Cut Rules in SheetCAM to turn the DTHC off on corners and before the end of the cut.

In CommandCNC (which is even faster than MACH with the DTHCIV) we have the advantage of having everything happen in real time. The motion is not buffered up so we can read the actual velocity in real time and turn the DTHC on and Off very rapidly . The toolpath tracking in CommandCNC favors accuracy over speed so it naturally slows down more on corners and at the end so by monitoring those speeds we can predict a head dive from a slow down.

Only in rare cases do you need any cut rules with CommandCNC.
BensPlasmaAu
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Re: DTHC Raising but not lowering

Post by BensPlasmaAu »

So I should look into upgrading to CammandCNC? Sounds like the go from what I have read. Since changing the voltage required and the tip saver settings, I have had 1 instance of the DTHC going into a loop and sending the torch uncontrollably downwards. Once in 6 full sheets of cutting is not bad. I have also increased the consumable life b6 at least 3 times. I haven’t had to change a tip in those 6 sheets.
Home built 3400 x 1400mm (11 and a bit X a bit over 4.5 feet)
Hypertherm Powermax 45
CandCNC Bladerunner IV
Some air dryer off the internet
Another water seperator I found unused on a shelf
Refrigerated air dryer
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