Hypertherm 45xp starts cutting then stops skips area then starts back

[fullthrottle]

Please help... I have a hypertherm 45xp. It will start cutting the image then stop for a split second jump a space then start back cutting. It will do this several times while cutting the image there for the image is not completely cut out.

[jimcolt]

Pictures of the cut will help (video even better), what consumables, power level, cut speed, cut height etc., and what brand of cnc machine?

Jim Colt Hypertherm

[SeanP]

That sounds a bit like my problem,
http://www.plasmaspider.com/viewtopic.php?f=3&t=24498
Does it happen every time or just now and then?
Is it on all thicknesses?

[KSFab17]

Same issue. And everything is brand new- torch, Bladerunner kit, all the modules (ohmic, pwm, rs485), consumables. Air pressure at 85, cut speed 150ipm, 12ga mild

[SeanP]

I've not seen it happpen on less than 10mm on mine.
Still not sussed it yet, cutting some 20mm yesterday using a chain cut, it did very well, just the crossover it lost arc again.
Yet I can plug the hand torch in and cut across gaps no problem at all.
Video here:
https://photos.app.goo.gl/o2YNgjqc0mSzrtDS2

[tcaudle]

Pictures of the cut will help (video even better), what consumables, power level, cut speed, cut height etc., and what brand of cnc machine?

Jim Colt Hypertherm

Question on the XP:

Does it behave like the other Powermax series and if the torch on signal drops out momentarily then turns back on immediately the torch will not refire?

If it was the torch on signal flickering would it eventually refire the torch?



The other question is for the persons with that problem: There are two indicators on the system to show the torch fire status . One on the PWM module and one on the RJ45 jack of the DTHCIV module. Both should stay on steady. It seems strange that it happens on some thickness and not others.

[KSFab17]

Ours does it for any thickness, randomly. We bypassed the "watchdog" and haven't had an issue yet. so from that, can anyone help narrow down the issue? I'd like to run my table at 100% safe/ full capacity

[SeanP]

''Bypassed watchdog'' is that the tickbox in Mach 'use watchdogs' ?

[tcaudle]

''Bypassed watchdog'' is that the tickbox in Mach 'use watchdogs' ?

No, its the Hub WD signal to the DTHCIV. It has a separate watch dog to sense loss of hub connection (RS485) . The system will run fine with it bypassed. If there are no other problems (like total loss of the feedback of the volts on the screen), then its going to cut fine. All it effects is torch fire...period

[SeanP]

Ah right, thanks Tom.

[tcaudle]

sean: What rev of the UBOBIII card do you have. On rev 15 and later we switch from doing muxed outputs (that if noise gets into the parallel port can cause "flicker" to a direct output dirve. It dropped the number of possible outputs from 8 to 3. Snce you have an older system you may have the older UBOB rev. We sill have newer UBOB 16 with parallel port and serial port for the DTHCII in stock

There is a "Lamp test" you can run that will point out problems with either MACH timing or noise. I dunno why it would appear only with the 45XP upgrade (and not on the older 45) unless the higher power of the XP is putting out more noise. Other factors like MACH timing and the PC being optimized for MACH would have affected the older 45 too.

.

[rons]

How do you turn off the separate watch dog to sense loss of hub connection (RS485)

[SeanP]

Yes rev 12 in mine Tom.
I remember going through the lamp testing when i first setup as I was having intermittent loss of arc in the middle of cuts, I swapped to a Dell 745 and that cured that problem completely.
If I knew for sure it would be the cure I would go for the ubob but with delivery and customs to Ireland it adds up.
I'll read up again on the lamp test, I forget if you can use that while actually cutting.
Thanks again.

[tcaudle]

How do you turn off the separate watch dog to sense loss of hub connection (RS485)

Find the "WD Bypass" jumper on the top of the DTHC IV module (two pins) and use a .1" jumper to bypass the signal. It only works to to prevent the loss of WD from firing the torch.

[jimcolt]

Tom, The Powermax45xp is different from all of the other Powermax units in that the switching frequency of the inverter is higher (this is why it produces more cutting power than the original 45). This higher frequency can create a little more noise on the interface cable that could possibly be shaking up the interface electronics. In regards to the start.....if the plasma extinguishes and the start signal remains on.....the plasma will not refire until the start signal is released then issued again.

I have seen a few cases )on one specific brand of low cost cnc machine) where the 45xp affects the interface...yet our other Powermax units do not. This is solved with Ferrites on the interface connections and carefull placement of the interface cable. Jim Colt Hypertherm

[SeanP]

This is solved with Ferrites on the interface connections and carefull placement of the interface cable. Jim Colt Hypertherm

Maybe that might be worth a try in my case?
so is that a ferrite on each of the wires in the interface cable?
Is there different ratings for ferrites I don't know much about those.

Thanks
Sean

[Brand X]

I was wondering why I liked the 45XP better then my 65.. (45 amp stuff) Seems to me the 45 was more powerful using my hand torch of .750.. I did not use my 65 much there to compare. but was unpressed when checking against my victor with 60/80 amp consumables.. One main thing was the input power on both cutting .750.. After that I knew the 45XP was very special in efficiency.Very nice mahine.. (IMO)