Replace a PT-31 with a S45?

[db556]

Well our school it building a SAE mini baja car and we were using my old mosfet Lotos branded CUT40D well till somebody smashed the torch and not wanting a PT-31 again I bought a 25foot Trifamet S45.

So seeing your forums are the best of all the chinese plasma cutter companies I ask these questions, I bought this back in the day (like 08') when all the chinese cutters were blue boxes. And I know from opening the cutter it was made by Chiry from before the fake mosfet problems.

So the question I pose is how would one deactivate the HF start? I see a two wire lead coming from between the Shunt and the Torroids leading down to near the flyback transformer on the lower board with spark-gap and solenoid relay.

If I unplug this lead the HF start is deactivated. But I doubt this is completely correct.
What would be the correct or best way to deactivate the HF start?

Now I've made a coupler from the female fitting on the S45 torch which I believe is a 1/4" straight british fitting to the fitting on the CUT40 which I think is some kind of argon or other gas ball seat fitting.

The second question is what do you think these fittings are? I know they are mostly all the same on the PT-31s

And the third question is, after attaching the S45 torch and soldering on the 2 pin fitting, and attaching the return lead to the ground fitting. I then disconnected the two wire lead from the first question and I trigger the torch. IT WORKS!!! but only for a second the pilot arc is only up for less than a second. If I am able to get the pilot arc start the arc to the work, the S45 torch cuts beautifully! If not there is the 5 second torch post flow, now too the question.

What is the usual time duration for the pilot arc? Is the pilot arc for a CUT40/50 cutter with the S45 torch momentary like this ?(its under a second right now) or it is continuous? The second part of the question is there a way to change the time for the post flow? I know there are switches for manual/auto or 2.5/5 seconds now. I can see two variable resistors on the end of the top board of the cutter from near the location to the leads from the amp control potentiometer.

Now I know this is not a Everlast Plasma cutter but this seemed like my best bet for an answer. I'll get pictures of the internals in a minute.

Thanks

-Gabe
RMU baja

[Ray]

Db556,
Wow I’m amazed you have gotten as far as you have. You’re missing a feedback loop to make it work.
If you give me a call I can explain better, but probably wasted your money on the s45.
877-755-9353X207

[performance]

The unit has to support a pilot arc. The unit will probably blow up eventually if it is incorrectly used. There are timing issues with the way the power is handled until the arc starts as well.

[db556]

Well I guess I call tomorrow, we will be needing my plasma cutter working soon, So I've got to get this running somehow, got multiple 4x8 sheets of .120" aluminum to cut. I've got some pictures of the internals of the cutter but, I think you guy already know what going to be there. Now the hard part, we don't have time to get another PT-31 so got to get the S45 running but really don't have the money to blow it all up.

I wonder if could I just run the S45 torch with the HF start still active just jerry rig the torch to stop the electrode from moving stopping the contact start.

My jerry rigged connector


Left side


Right side



Here you can see the two wire connector I disconnected its the green and black wires



The top

[performance]

The AG 60 torch we have will work. The s-45 should not be used.

[jakeru]

My Super200P came with the PT-31 plasma cutter also. The threads on the power/gas fitting are M16 x 1.5mm. I've got a M16 x 1.5mm tap set that I used to make an adapter to hook up an aftermarket TIG torch to this machine.

[db556]

Actually put a listing on our local craiglist and some one gave me a PT-31 from their burnt "yineharda" CUT40 I looked at it when I was talking to him, 6 of the mosfets were burnt out, didnt see any info on the good mosfest must have been from that batch of 'wisdom' mosfets. Hooked it up, now I only need to get some type of jacket to cover the cables.

But now I have a S45 with no project........yet
but I know out local used tool store has a old transformer based plasma without a torch, and a case for that matter seeing as its just a bridge rec, a couple SCRs and some capacitors there shouldn't be much to burn out I think I'll see if I can get that for cheap to experiment with. Because the HF start was playing havoc with out cnc plasma table.


Performance, you list a AG-60 torch is that a HF start pilot?