Fiddling about with an old Cebora.

[8ob]

Had this prof55 for years, died a while back and was pushed under the bench. It resurfaced last week so fitted a new P80 style torch and away it went. Thought I would try and dial it in so ordered in from Amazon a drag shroud and some different nozzles.

The drag shields were a bit too long and they snuffed out the arc so I trimmed off some of the insulator to lower the tip.

Tip now sits about 4mm off the work.

Vs

Best I could do with the drag tip out of the box was below and the kerf would need attacking with a grinder.

Dropped down a nozzle size to 1.1mm, messed about with the air pressure and using the modified shroud it does this, kerf taps off. Still a way to go yet but it’s getting there.

 

[zzr1200]

I had to adjust the air pressure when I converted my R-tech 50hf to a P80 torch.

I never even considered adjusting a nozzle height inside the drag tip assemble.

I must have a play soon, to see if I can improve the cut quality........

 

[Erie Fred]

what air pressure are you trying ?

 

[zzr1200]

what air pressure are you trying ?

R-Rech state 70psi for the standard fitted torch, the P80 lowers that to about 50 to 60psi depending on nozzle hole (1.1/1.3) using an Aldi V2 13cfm compressor.....

When I first fitted the P80 torch the plasma stream was spitting on/off, I found by lowering the pressure the plasma stream stabilised.

 

[8ob]

I had to adjust the air pressure when I converted my R-tech 50hf to a P80 torch.

I never even considered adjusting a nozzle height inside the drag tip assemble.

I must have a play soon, to see if I can improve the cut quality........

The only reason I hacked a lump off the drag shroud was it cut okish with the standard shroud that came with the torch, it was then I noticed how far the stand off was from the work, it should be anywhere between 1/8" to 60 thou stand off according to the web. I will have another go at it later, I will try and get the tip down to a 1/6", it certainly made a huge difference to this setup both in piercing and cut..

Bob

 

[Erie Fred]

R-Rech state 70psi for the standard fitted torch, the P80 lowers that to about 50 to 60psi depending on nozzle hole (1.1/1.3) using an Aldi V2 13cfm compressor.....

When I first fitted the P80 torch the plasma stream was spitting on/off, I found by lowering the pressure the plasma stream stabilised.

As there is no P-80 charts that I can find, I tried several settings and landed on 65-70 psi.
I don't find there is any "tuning" other than running less than 65 results in a bad cut.

 

[zzr1200]

As there is no P-80 charts that I can find, I tried several settings and landed on 65-70 psi.
I don't find there is any "tuning" other than running less than 65 results in a bad cut.

The only thing I can say regarding "The Pressure" is that the gauge I'm quoting is the pressure gauge built into the front panel of the R-Tech Plasma 50hf cutter, that I fitted the P80 torch too.

When I replaced the standard fitment torch with the p80, the plasma arc appeared to be blown out by the air flow/pressure, causing an intermittent plasma arc jet, so I tried reducing the pressure which stabilised the plasma flow....?

Maybe the pressure gauge fitted to this machine gives an incorrect reading............ all I can say is that when I use this cutter now the pressure appears to be 50/60 psi depending on the nozzle size I fit.

Theoretically for a set ampage/air pressure/nozzle hole diameter all plasma cutters should be equal and be able to cut the same thickness of material, but they aren't that's why there's cheap far eastern machines and the likes of Hypertherm.

When I get some spare time I'm going to play with the nozzle/material gap height on my drag tips, as per 8ob post above, and see where that leads me........

Then there's the 125 amp plasma cutter 415 volt 3 phase machine (German/Far Eastern........who knows) that's also fitted with a P80 torch as standard in my garage/workshop, yet another set of figures/nozzle diameters.

 

[Erie Fred]

The only thing I can say regarding "The Pressure" is that the gauge I'm quoting is the pressure gauge built into the front panel of the R-Tech Plasma 50hf cutter, that I fitted the P80 torch too.

When I replaced the standard fitment torch with the p80, the plasma arc appeared to be blown out by the air flow/pressure, causing an intermittent plasma arc jet, so I tried reducing the pressure which stabilised the plasma flow....?

Maybe the pressure gauge fitted to this machine gives an incorrect reading............ all I can say is that when I use this cutter now the pressure appears to be 50/60 psi depending on the nozzle size I fit.

Theoretically for a set ampage/air pressure/nozzle hole diameter all plasma cutters should be equal and be able to cut the same thickness of material, but they aren't that's why there's cheap far eastern machines and the likes of Hypertherm.

When I get some spare time I'm going to play with the nozzle/material gap height on my drag tips, as per 8ob post above, and see where that leads me........

Then there's the 125 amp plasma cutter 415 volt 3 phase machine (German/Far Eastern........who knows) that's also fitted with a P80 torch as standard in my garage/workshop, yet another set of figures/nozzle diameters.

When it was "blowing out" was that in free air, or on a piece of steel ?

As far as applying a p-80 to a 125 amp machine, that will overload it, the p-80
is really only good up to 100 amps.
Look at an a-141 torch, it is an HF start torch.

 

[zzr1200]

When it was "blowing out" was that in free air, or on a piece of steel ?

As far as applying a p-80 to a 125 amp machine, that will overload it, the p-80
is really only good up to 100 amps.
Look at an a-141 torch, it is an HF start torch.

I purchased the 125amp machine new, the supplied torch was a P80.

It was advertised as a 125 amp machine, but being as I suspect it has a far eastern origin (via Germany/Poland), it maybe able to supply 125 amp for a nano-second of initial arc, 100 amp is probably more like it, but for the price, I was willing to take a punt....

atm:- It works, it cuts, until the magic smoke exits stage left................

Expondo shop

Deep, precise cuts with the 125 A plasma cutter from Stamos. Get it now at the best price from expondo!

www.expondo.co.uk

 

[zzr1200]

When it was "blowing out" was that in free air, or on a piece of steel ?

Both, I think the extra pressure/air speed caused by the tapering cone of the drag nozzle shape was causing the plasma arc to be blown out, then the hf circuit restarted the arc.

It didn't seem to make a difference if was cutting material or just held in mid air not cutting, the plasma jet was intermittent, lowering the air pressure solved the problem and improved the cut quality...

 

[Erie Fred]

Less air is less cooling, leading to shortened tip life.

 

[8ob]

Had another mad five minutes on this today, by boring out the drag tip I have managed to get the nozzle stand off clearance down to 3/16”.

It’s got scope to go down to 1/16” but will need more clearance for air cooling in the shroud.

Massive improvement on the cut and more impressive is the slither it can now cut, that slither would have been a blob of molten metal on the floor. Its a freehand cut but it is now not walking.