Torch vs Plasma ipm

[Arc Burn]

Well i'm getting ready to buy a plasma(better late then never) probably the Cutmaster 38 and i have noticed the plasmas all list there cut rates or inches per minute(ipm) anyone have some standard info on oxy/acetylene or oxy/propane in regards to ipm?I said standard because i'm not lookin for the hot shot that blows thru steel crooked with tons of slag,just an honest comparison.

[Arc Burn]

Wow,all this knowledge and no one dares take a crack at this one?

[Franz]

Having been at this spark makin thing for over 40 years, best I recall, torches have always been rated in terms of inches of penetration capability. I've never seen numbers relative to a torch as to how many inches of 1" steel per minute it could cut.
Cut Inches Per Minute seems to be a statistic invented to sell plasma machines.
Honestly, I sort of think of it the same way I see miles per gallon on the window of a new car. A lot of torch or plasma cutting capacity is determined by the operator, unless you're talking about an automatic or robotic situation.
Then again, I could be wrong.
Your mileage may vary.

[ZACHV]

Having used my new Hypertherm 380 now a few times I would state that the rates of cut for plasma to torch is atleast twice, as long as the maching is rated to cut that particular guage material. For instance, I make these things for Jeeps:

and with a OA torch it would take me atleast twice, if not three, times as long to make that cut. Also, with the next to no cleanup required with the plasma cutter I save even more time. All I do is gring the edge flat real quick and run a smoothing wheel down the edge and I am done.

[Dave Haak]

ZACHV,

The "things for jeeps", what are they?

Smoothing wheel? Does this do the same thing as a "V" shaped carbide deburrng tool?

Dave

[Sberry]

Not to mention the only distortion comes from stress relieving and not warping from heat. Really great on thin sheet. I also dont pay a lot of atn to the IPM, I think I pay attn a little more to the thickness it will cut for a rating. For a larger shop my Lin Pro-Cut 60 would be a little light but I did cut some 7/8 cast plate the other day rather well. I thought it might be a problem but it wasnt. It was rated for 1/2 steel plate when I got it. I liked it because of rather simple componants actually although the torch could be better. I have a 50 ft lead also which I find really useful, a little heavy on the bench but great for the reach on equipment.

[Guest]

Bottom line, is plasma is faster than O/A. In a machine, you wouldn't notice the difference.

I find that for me, hand cutting with plasma is difficult to see the flame, and keep it on the line with out some sort of guide. The O/A torch, however, I can cut right on the line without a guide and with a clean tip, and steady hand I can get a slag free cut most of the time.

I have a Miller 3080 and It will blow through anything quick, and what slag there is pops off with your finger. I do notice, that the tips have to be changed more frequently that O/A tips, though. $$

[Roger]

Plasma cut speed is so fast you can have trouble keeping it ontrack on thin metal. The big advantage for Oxyfuel cutting now days is cutting thick steel which isn't an issure in most home shops unless your into making steel anvils.

[ZACHV]

Originally posted by Dave Haak
ZACHV,

The "things for jeeps", what are they?

Smoothing wheel? Does this do the same thing as a "V" shaped carbide deburrng tool?

Dave

Dave, they are called "rocker guards" The protect the side of the Jeep when the owner drives over rocks and stumps. Without them the sheet metal gets real bent. Here is an example of them mounted:

[TWG67]

Here is a chart that shows general torch cutting presures and speed.

[Sberry]

Thats a really good chart and it pays to notice how low the pressures really are. 30# oxy at inch thick. Most of us tend to use it too hi and it is hard to train people to turn it down for quality plate cutting. Of course that doesnt always take in considerations of real world conditions but is a good guideline for those who want to learn the fundamentals correctly.

[d.paulson]

That's a great chart. Just for comparison sake, my max100 speed for 1/4" is 95 ipm while 1/2 is 40 compared to 20 and 16 respectively for o/a. max mechanized cutting with max100 is 5/8 while o/a with the proper tip and a three hose torch can cut up to 12", so there is a need for both machines in a shop.

[Dave Haak]

ZACHV,

Pretty fancy rocker guards!

How about more info on the smoothing wheel? Just trying to further my education.

Dave

[Sberry]

Sure theres a need. Cant heat a nut with a plasma or cut a bearing race off well. I like it for cutting rusted nuts off and actually I like torch for scrapping equipment most of the time. Heat for bending. Burning paint or oil off. Warming parts for weld preheat. I took a O/A torch the other day and blew a hole in a 1 inch bolt for a cotter key when I was in a hurry. We could probably think of other uses for a torch and I use in the field on the service truck.

[ZACHV]

Does anyone have a pic of an OA torch cutting 12" material?? I have heard of that, but cannot fathom it. This is amazingly thick.