Help seting up 3 tube oxy fuel torch.

[saxa]

Hi all, I am doing a plasma and oxy fuel retrofit and I would like to do some tests with the oxy fuel torch. I am trying to cut a piece of steel but have been not able to cut it at all. My first mistake was that I connected my torch (Harris 198-2TF/35) which has 3 tubes
to the acetylene, oxygen and compressed air. Then I went reading a bit and got it out that I must have oxygen on 2 of the 3 connections. One is for acetylene, one for pre heat oxygen and the third one is for the cutting oxygen.

My questions are the following:
1. How do I split the oxygen supply from the oxygen cylinder ? Is it worth setting up a new cylinder with another pressure regulator or I can use one cylinder for both oxygen entrances ?

2. Is there any problem if I use the cutting tip 6290-VVC (propane) with acetylene gas ?

I tried many google searches but was unable to find any valuable advice on the above questions.

Rgds
Saxa

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[mattcnc123]

Its better you use two separate oxygen cylinders with separate regulator

for preheat you need lower pressure for oxygen

for cutting you need higher pressure.

Also you need safety checkvalves before torch.

its better you use correct tip.

matt

[asuratman]

If you use 3 hose torch, 1 of oxygen hose connected to solenoid. You can control solenoid open and close with mach3/uccnc, you need to edit post processor if using sheetcam. I use 2 hose torch, its easier to handle. I cut 5 mm steel plate using tip no 000. You can try the speed time to time.

[saxa]

Its better you use two separate oxygen cylinders with separate regulator

for preheat you need lower pressure for oxygen

for cutting you need higher pressure.

Also you need safety checkvalves before torch.

its better you use correct tip.

matt

Dear Matt, many thanks for your answer. I will get another Oxygen cylinder and yes, I have fire return valves on my torch on both hoses. I will buy another flashback valve for the cutting oxygen also.
For the tip, I probably have to get the propane/butan gas instead. It is easier that way as the location where I am many people never saw the Harris 6290 tip, so I have to check what will be faster and easier to me. But it is possible to do the cut with Acetylene gas and the 6290-VVC tip ? Any idea ? I believe it will work, but probably the tip will have faster wear or something like this. I have not saw many differences between the 6290-VVC and 6290-AX or 6290 tips. Any comments ?

[saxa]

If you use 3 hose torch, 1 of oxygen hose connected to solenoid. You can control solenoid open and close with mach3/uccnc, you need to edit post processor if using sheetcam. I use 2 hose torch, its easier to handle. I cut 5 mm steel plate using tip no 000. You can try the speed time to time.

Hi asuratman ! Thanks for the reply. I plan to use that oxyfuel/plasma machine with Linuxcnc maybe with MAch3 too. I will experiment a bit with both, although my personal preference is for Linux.
Can you send me a sample config or link it here ? In fact I am just doing some tests, and have to cut a steel plate urgently and want to try it with the unfinished machine, but in the final setup I plan to
automate as much as possible.

[asuratman]

My built was just following common wiring chinese CNC BOB STV2. Then I added UC300ETH - 5LPT board. I use cnc plazma UCCNC program, then config as per hardware. Nothing new. It works perfectly with my oxy cutting torch. I have both US made 2 hoses and chinese made 3 hoses torch. I use my 2 hose since it is easier. I still need macro program for my 3 hose. I use solenoid on 3rd hose oxy since I saw alot of chinese 3 hose here used solenoid. I still got not good cutting results yet, I need some more practices to get a suitable cutting parameter.