torch height control

[brucer]

you guys running the cnc plasmas.... are you running thc or no thc?

[Gadget]

I'm not using it.

[KHK]

Not rich enough for THC.

[SAS Company]

I ran two tables one with, one without. I did not care for thc. Unless you are cutting corrugated metal, I prefer the "spoon" type height control. Basically the torch is held at a specific distance from the metal by 6 transfer balls (mcmaster #6460K21 or similar) contacting the metal you are cutting. An air cylider lifts and lowers the torch between parts. The rollers keep perfect height every time.

[Gadget]

Do you happen to have any photos of the setup you described Jon? It might be something worth building from the sound of it. Does the spoon leave any marks on softer metals (aluminum)

[SAS Company]

this video shows a table using the setup I tried to describe MultiCam 1000 Series CNC Plasma - YouTube. The rollers leave a faint line where they travel but don't leave a permanent mark. For a home shop, I don't know that you would even need to lift between cuts.

[Gadget]

Thanks that helps. Does the fact that the pierce and cut are always at the same height affect the consumable life at all?

[SAS Company]

With a fine cut tip at 40 amps have run 1000+ pierces on 16ga hr on one consumable set. If I remember the part right that would be over 400 feet of cutting too. Consumable sets were replaced once the kerf was not square. Never got more than 1/4 sheet with the old thc and the identical torch.

[Gadget]

Next question, what's the diameter of the ring. I think you said there were 6 rollers in the ring right?

[KHK]

The only possible problem that I see is doing a plunge cut there is some blow back which can be above the metal's surface Maybe low air pressure will allow the head to ride over the bump.