CF Pro + Razorweld Cut 45 losing arc after a few seconds

Pretty new here, and to CNC Plasma as a whole. My dad and I recently finished assembling our crossfire pro table and seem to be running into quite a few teething issues. While there has definitely been a learning curve, and many of the other posts on this forum have been very helpful, the biggest issue that we are facing is that there will be fits where the majority of the time we are having difficulty piercing the material, and our arc will cut out after just a few seconds. That said, when it does cut, it cuts perfectly every time, not dross, next to no bevel, perfectly smooth edges.

The settings that I have been using were influenced by that fairly comprehensive RW 45 cut chart that has been posted here previously, so for the 3/16 mild steel plate that we have been dealing with mostly it has been:

  • 1.2 sec pierce
  • 40 in
  • 40 amp
  • .02 springback
  • .005 cut height (Our torch has a drag tip, so the actual cut height is closer to .065)
    There are no common grounds between the computer and the table, the plasma cutter itself is as far away from the table’s control board as the hose will allow and the shop air system is able to keep up with the demands for the torch.

With these settings, we’ve been getting some more reliable cuts, and like I said, when it cuts it cuts perfectly, but it is still having fits very often where nothing wants to work. The same G-Code, the same piece of material, ground clamp location, pierce delay, feed rate and everything will work great for one cut and not at all for the next 10 tries, then seemingly magically work again.

I am sure that the issue is something to do with operation and not the machine itself, but I’m also fairly well versed in G-Code based tools (several brands of 3d printers, co2 lasers, g-code based vinyl cutters and the like), so I’m aware of how finicky they can be sometimes.

Any help would be greatly appreciated, I’m sure I left something out of this post, so if there is more information that would be useful, don’t hesitate to ask. I’m just really hoping to get this thing working.

Welcome to The forum.

What’s your Pierce height?

I would sand off those drag Shield standoffs and order a proper machine torch deflector.

What’s your incoming air pressure at the plasma machine?

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Thanks for the welcome!

  • Pierce height is .050, plus the ~1/16th of the drag guard, so actual is approximately .115
  • We’re looking into getting normal tips for when we replace the consumables, but if this keeps messing us up I’ll probably introduce the torch to my dremel
  • Air pressure reads 70psi on the cutter, and the compressor is able to kick on and build pressure in the tank while the table is running. We also have an inline air drier in the system, though we’re looking to upgrade to a refrigerated drier if we are able to get the table to pay for itself.

Is the air pressure 70 psi supply to plasma cutter or torch supply? You want 70-75 at torch and 110psi supply to plasma machine. Need to get rid of drag tip and put machine shield in as TinWhisperer stated, or your frustrations will continue. Pierce height .115 and cut height .058 - .060 .

Air pressure is 140 at the tank, and the compressor kicks on 80psi and can build pressure while the cutter is running. The pressure indicator on the cutter itself for the torch pressure never dips below 70.

Looking around some, I found this from George’s Plasma Cutting who seems respected around here. Is this the type of guard you guys were talking about?

Compensating for the 1/16th gap of the drag shield, my cut height and pierce height are .068 and .113, though I’m sure the shield being lower probably messes with my voltages some.

Depending on how much restriction you have between your plasma cutter and the tank I would kick this on at 90 or 100.

And I would up your pressure at the machine like @rat196426 said.

order that new Shield for mechanized cutting and sand the drag tips off your other one in the meanwhile.

And then set your post back to a normal cut height

Your experience will improve quite a bit if you do these two things