Controller losing communication!

[puffernutter]

Is the failure upon initial firing ?
Or after the arc get's transferred ? (or attempts to xfer)

Initial firing and then occasionally along the workpiece

 

[Erie Fred]

Initial firing and then occasionally along the workpiece

If it was when trying to xfer, I would suspect the main ground to the plate.
However this is an intermittent problem.

Unless....."along the workpiece" is happening all with pilot arc.

 

[sako243]

Have you always had a ferrite ring on the USB cable, or did you add it to try to solve the problem?
Since USB is digital, a ferrite bead will tend to slow the risetime the signals, which could cause timing problems.

In my experience they're a bit of a hail Mary. They're usually very narrow band and limited in their blocking capabilities. Unfortunately as the issue seems to be affecting @puffernutter's USB then the frequencies you want to block are probably the ones that you need to let through...

I'm not saying they don't have their place but after spending months trying to get a bit of kit with a lot of third party computer components in it through EMC they weren't actually as useful as everyone thinks.

@puffernutter - if I've understood this correctly the setup was working fine in its old location but no longer now you've moved it?

 

[sako243]

One thought - have you tried manually cutting a piece of steel with the same plasma? Let's eliminate a plasma issue first I've always found mine to be finicky over firing (P50HF) and I've had one torch lead replaced FOC by R Tech because there was a suspected break in one of the wires (it had been fine then started being intermittent, they took it back and everything was behaving and then just before they were about to return it it failed to fire once so they swapped out the torch and never had an issue after that).

 

[knighty]

ok... my interference knowledge is pretty limited... but can't you hang ot bend a steel sheet between the plasma/table and the pc?

 

[puffernutter]

A quick update. I have spent the last two days making a new fitting for the Hypertherm 350 torch. As suggested, I thought I'd try a larger machine (as I had one I bought recently off a gent from this forum) and I had the chance to try it today. Whilst I had bought a USB isolator I decided, in the best of engineering trials, not to change too much at once! The only change I made, as the Hypertherm had longer leads, was to site the cutter unit a little further away from the table. I did a trial cut on 3mm plate, which it cut out with absolutely no issues, no stopping, spluttering and the connection was sound throughout. I wonder if the Hypertherm with a higher current is able to maintain the arc better and there is much less interference on the USB. Anyway, until the next problem raises its head (well it has, but that is just my lack of experience with G-Code) I think we can close this one off!
Thanks again for all the ideas and support - much appreciated.

Peter

 

[sako243]

Does it have pilot arc as well or HF start or neither? They can all cause different issues.

 

[Erie Fred]

A quick update. I have spent the last two days making a new fitting for the Hypertherm 350 torch. As suggested, I thought I'd try a larger machine (as I had one I bought recently off a gent from this forum) and I had the chance to try it today. Whilst I had bought a USB isolator I decided, in the best of engineering trials, not to change too much at once! The only change I made, as the Hypertherm had longer leads, was to site the cutter unit a little further away from the table. I did a trial cut on 3mm plate, which it cut out with absolutely no issues, no stopping, spluttering and the connection was sound throughout. I wonder if the Hypertherm with a higher current is able to maintain the arc better and there is much less interference on the USB. Anyway, until the next problem raises its head (well it has, but that is just my lack of experience with G-Code) I think we can close this one off!
Thanks again for all the ideas and support - much appreciated.

Peter

The hypertherm 350 is snap start ?

 

[puffernutter]

The hypertherm 350 is snap start ?

All I can find is "The PAC110 torch is an instant-on torch which produces a plasma arc immediately after the torch start switch closes." from the Operators Manual. The unit is now discontinued.

 

[Erie Fred]

All I can find is "The PAC110 torch is an instant-on torch which produces a plasma arc immediately after the torch start switch closes." from the Operators Manual. The unit is now discontinued.

You have switched from a Hi-freq start R-Tech plasma cutter, to a Hypertherm 350 with snap start ? (no hi-freq)