I like differential step/dir signals and also 24v I/O, much more noise immune.


Hood

Hmm, that sounds like a complete different control system?

Just had a chat with the suppliers and they feel the generator is not switching to full power i.e. I am cutting (or trying to) with pilot arc power which is about 20A on this model

They are sending me a new (tested good) hand-held torch for test purposes and while waiting they have advised me to try upping the air pressure to 75psi just for a test.

But basically at 30A and 1.5mm sheet, it should practically vaporise the damn thing at the slow speeds I have been trying!!

Will know more tomorrow.

Hmm, that sounds like a complete different control system?

Ideally yes but you could also do a lot of it yourself if you need to. I used to have to do that on my machines as all that was available was 5v i/o boards and single ended step/dir. I made up line drivers for the step/dir but my drives accepted  differential, if yours dont then you would also need to make up receivers as well. 24V I/O can be done different ways but it can get messy with relays etc. The controllers from CS-Lab do it all for you in a small neat package but likely you would only want to consider going that route if you cant get the better of your problems.
Hood

I think this BOB is toast really, its the original one and the LED for the relay is off when initialised but after it warms up, the LED is half-on. It still switches the relay as required but the LED goes from full to half power not full to off.

When i started testing I had the BOB powered from the stepper drive PSU, this I now know was bad idea so I am hoping it was this that did the toasting.

I have a new BOB sitting here, just not sure to try it or not.

I now have fitted a small PSU purely for the BOB and its on a filtered supply too, cant do much more than that.

My other issue turned out to be the machine torch, its a duff one, the new test hand-torch they sent me today cuts really well.

Well, i'm getting baffled again, the new torch arrived this morning and results seem to be better but something is still wrong.

In this picture...
http://www.landyzone.co.uk/lz/members/davek0974-albums-problems-picture15119-photo-1.jpg

The long cut is made at 20A @ 4000mm/min, its a nice fine cut about 0.5mm kerf with zero dross front and back.

After that success I thought I'd load up a little test file i've been messing around with and try that after editing the sheetcam settings to suit the new parameters...
http://www.landyzone.co.uk/lz/members/davek0974-albums-problems-picture15120-photo-2.jpg

Now, this was the second run as the first one at 4000mm/min was worse so i dropped to 3750mm/min but all i got was a pile of dross and partial cuts.

Both tests were pierced at 4mm (mfg recommendation) and cut at 1.75mm (mfg says 1.5 - 2.0mm)

Now this tells me that something is badly wrong but my lack of experience does not tell me what.

Any pointers here???

Also, I have set a pierce delay of 0.1 sec in sheetcam but mach3 seems to stay for at least a second or so.
Does Mach3 have a default minimum pierce delay??

Well it seems it is lack of current, this was run at 30A...


Its pretty good I think, I have axis wobble to fix but the cut is clean there is no dross front or back apart from a small amount where it slowed down for the corners.

Still 100% better than the first go.

Although I am happier now, I still fail to see why 20A will cut an excellent straight line but produce so much dross and crap on a simple shape at similar speeds??

Oh, and I still need to fix the pierce delay issue, I have 0.1s set but its holding so long that the torch starts popping before moving due to lack of metal in front of it.