Question? Heavy plate edge starts

[plain ol Bill]

I have a need to cut some 1" plate using my Powermax 1250. It will require an edge start as the cutter will not pierce this thickness. I have never tried edge starts before and am not really sure just how it is done. The parts are a 4" square with a square 1" hole in the center of it.
Tell my how you would do this guys --.

[ryno fab]

the way i have done it in the past is kind of a pain but you gotta work with what ya got.
for the holes in the center i would figure out where your pierce point is going to be. in plasmcam you just start you " cutting" with the autocontrol off. hit pause when needed and put a soapstone mark. after marking out your pierce points take a oxy/actl torch and blow a hole. once you get that done select the "pause before cutting" or just pause it before it starts up. on pcam there is a "test" button. i set my pierce time to 0. i will manualy pierce using the test button and hit the start button when its ready. now that i have a hole i can treat the center cuts like an edge cut and repeat the process. i realize that i said that in reverse order. you would want to cut the hole out first but you get the jist. a bit nomadic but it works.

[MQUICK]

I prefer not to cut steel over 3/8". Just tired of moving heavy plate. So I did not need a larger plasma. That being said, just to cover my butt if I needed to cut heavy steel, I set up a OA manual machine torch to fit my PlasmaCam. I turn off the auto height control and set it to the cutting height. I send the torch to the lead in cutting point. To switch from preheat to cut is just a flip of a lever. As soon as it pierces the plate I start the cut. When it's done cutting and the torch raises up, I flip the cutting lever back off.

If I was going to cut heavy steel a lot, I would get a bigger plasma. For the few times I need to cut a heavy part, this works great. No problems piercing and the smoothest OA torch cut I have ever seen. I also set the torch up to use propane instead of acetylene. It gives me the cleanest cut.

I got the torch, new, off of ebay for $100. With the torch, propane regulator and hose, it cost me about $200. The adapter from torch to table I made from stock.

They do make a machine torch that used a solenoid for cutting. This can be wired to the cutting control of the table. This makes the price really jump, from what I could find. If I did more heavy cutting I might look into it.

[plain ol Bill]

thanks for the tips guys. I only have to make two of these parts so I will try the plasma - not worth setting up a torch on the table for it. I'll let you know how it works out.

[muzza]

Bill, if you use your plasma to mark the pierce points you can then select a drill bit and offset the drilling so the pierce points are at the edge of the drilled holes.
Murray

[GoingCustom]

Bill, if you use your plasma to mark the pierce points you can then select a drill bit and offset the drilling so the pierce points are at the edge of the drilled holes.
Murray

anything 1/4" and above, I manually drill the pierce points to help save on consumables. Takes a little long having to drill them, but it makes for an "edge" start when cutting from inside heavy plate. Thickest I've done so far is 3/4" and was able to get near perfect edges/0 bevel. True edge starts are easy, just adjust the pierce point so it starts at the edge of the table so when the machine moves to the pierce point, it is actually at the edge of the steel and/or slightly offset the steel so the pierce point starts outside of the steel if that makes sense?

[jimcolt]

The Powermax1250 can pierce pretty well up to 3/4".......on 1" you can pierce as well....however you may want to use an old shield and nozzle. If you are just doing two parts.....set the pierce height at about .25", allow the torch to pierce completely (probably about a 1.8 second pierce time) than hit the stop button. Then, advance to the next pierce point. Do this for each pierce point...now you will have your pierce holes....change to a new nozzle/shield and start your cuts on these holes......reduce the pierce hight to the spec in the manual, reduce the pierce delay time to about .75 seconds.

Piercing thicker than recommended can be done with the Hypertherm systems....however the blowback will damage the nozzle orifice , which will affect cut quality...therefore it is good practice to just do the pierce holes using old consumables. I pierce 1" all the time with my Powermax85...


Jim Colt