Big Red Tube Update and Air

[Blake Samuels]

On Wednesday night, mainly Fletcher and Kamil tried the 130W big red tube back in big red now we have the new power supply. The 100W "for Kellogg" tube was swapped out.

There initially was some electrical arcing between the HV end of tube and laser cutter body. That was resolved by cleaning the end cap (and some of tube?) with isopropyl. After that the arcing was gone but tube still would not fire.

The new laser powersupply display (temporarily mounted) reported that the tube was open circuit (in chinese - fletched did google translate/lens).

From that, we conclude the tube has totally failed. Maybe gas leaked out or something. We were observing a rapid decrease in performance in the month before power dropped off completely so perhaps this ultimate failure is related to the decline in whatever the root cause is.

The 100W "for Kellog" tube was swapped back in and required no realignment. 

During reattaching air fittings, etc we couldn't get the air regulator's water trap to stop leaking air. Various twiddling and cleaning was tried.

Instead Doug and Lemming helped us swap the regulator over to another one that was in the office. Its a smaller unit but still does regulation and has a water trap. Doug installed it and reattached the existing valve. Some of the fittings were changed  to be more "fit for purpose" which should further reduce air leaks. Pressure was set around 30psi. Flow out of laser head nozzle seemed about right.

Test cuts were done and big red cut some 3mm MDF at 50mm/s ok (square strip pattern).

The "dead" big red tube should be held intact for at least 1 month but no longer than 6 months. It is kept only on the chance that our diagnosis is wrong and that it can somehow be used. There was talk of turning it into a lit display piece which would look cool.

Blake