Thanks for the list, it's not patronising at all, especially as I'm fairly new to thermal spraying. I'll fill in what I can now and find out the rest when I get a chance.
- As far as I know, yes.
- No, generally the plasma jet is fairly stable and spark free. More sparks/streaks noticed towards end of electrode life, as well as falling voltage.
- Yes, it's been re-built many times for new nozzle/electrode, and each time checked for leaks. Leaks are quite rare.
- Not sure about the chiller and how often it runs/is left on for after coating. What do you mean by purging the gun?
- I can't remember when the coolant was last changed. Are you hinting that the gun may be overheating due to poor cooling? Is it normal to see cracks in the electrode as seen in the last picture above? How often would the coolant require changing? Weeks, months or years!?
- We do run the gun down, but possibly not in the way you describe. I'll investigate!
- Yes all gauges are currently in calibration.
- What do you mean by burner cables?
(03-02-2010, 12:31 PM)LEN WOOD Wrote: Have you always experienced short hardware life? If not then what has changed, supplier or configuration or?
The first nozzle/electrode that was in the gun when it was first used recently (it's been in storage for a few years apparently) lasted a long time. Since then we've had problems. No idea what has changed since then at all! All process controls are the same.
Another issue, but most likely related, is possibly with the 7MC cabinet. The F4 has been run at 700 amps but recently we've used 650 amps. (The electrode life issue was apparent before we changed the current.) At 700 amps the hardware was tripping out, possibly on over-temp. Could this be related to cooling issues as mentioned earlier?
Thanks for your help, really appreciated and I've got a lot to learn!
Loriolo - I would like to source some OEM spares but until I can prove that the issue lies there, I don't think I'll have much luck unfortunately.