How to select a plasma cutter?

[toolbox911]

I have just finished building a 5'X5' 2 axis cnc plasma table and looking for a suitable plasma cutter. Cutting thickness will be 1/2" mild steel, any recommandation?
I have been told to avoid high frequency start type, but could it be ok with a good grounding (earth) and torch sheild?

[DanOSB]

are u going to use a machine torch or regular torch?

im interested in what other people are answering.. im planning on doing the same capacaity as u.. and anything thicker than that will use oxy/acent torch.. from what i heard oxy/acent will be more cleaner and accurate cut anything thicker than 1/2 and plasma will do better on less than 1/2 inch thickness

[toolbox911]

Cutting machine come standard with hand torch, machine torch sell separately and I think is different brand too.
The actual capacity is 32mm, so I guess it should be able to do 100% duty cycle for 1/2" plate.
But, what I am worry is the interference it might create, because the arc start method is not the contact start type like the Hypertherm.

Does anybody successfully uses the high frequency arc starting cutter?

ps: Oxy fuel torch will be use for thicker plate, too bad it won't work for stainless steel.

[DanOSB]

for machine torch they do sell it seperately.. or if u request it and u can get machine torch instead of hand torch.. im going to do bit research about those two.. duty cycles are different for those two i beleive.. so i probably will do machine torch if its lot difference for the duty cycle.. and consumables wear and long term costs.. i know the machine torch itself is about +600 more extra for cutting torch....

[toolbox911]

Surprisingly the machine torch doesn't cost much from my local supply. Moreover, it is easier to mount and locating the starting point. The hand torch thus keep as a back-up or occasionally manual cutting.

Bellow is a link to the article about grounding issue http://www.centricut.com/New_Lessons/lessons_14.html

Does the solutions suggested in the article necessary if using the Powermax cutter that has relatively low frequency arc start?

[Death Adder]

I use a HF start plasma cutter on our burn table. I don't remember the brand of plasma cutter though.

Anyways, we had AWEFUL trouble at first. We kept blowing out encoders left and right. We had to thoroughly make sure everything had a nice big connection to ground and had to basically build a faraday cage around the controller. Once we did that we were able to cut as much as we want w/ the plasma w/o problems. So, if you use a HF start type then do yourself a favor and make sure you've got everything grounded properly! Then double check.

Originally Posted by toolbox911 Cutting machine come standard with hand torch, machine torch sell separately and I think is different brand too. The actual capacity is 32mm, so I guess it should be able to do 100% duty cycle for 1/2" plate. But, what I am worry is the interference it might create, because the arc start method is not the contact start type like the Hypertherm. Does anybody successfully uses the high frequency arc starting cutter? ps: Oxy fuel torch will be use for thicker plate, too bad it won't work for stainless steel.

[Rigid Racing]

I am using a hypertherm 1000 on my table and it seems to have a real hard time making good cuts on 1/2" mild steel. The kurf simply tapers off too much at the bottom to make anything usable at that thickness.

[DanOSB]

rigid racing u using machine torch or hand torch?

[Rigid Racing]

I am using the hand torch. I think it is a T60(?) torch if I remember correctly. If I had to do it all over I probably would have gone with the machine torch because it is much easier to align the head with the table.

[DanOSB]

ya.. thats one of main reason why im thinkin about having machine torch..

so those two torches will be sitting right next to each other

i already got the oxy/acent torch 180 degree head not machine oxy/acent torch but will use some cam for the valve for oxygen trigger.. simlar concept to http://www.cnconabudget.com/torch.html but my torch head is 180 degree so it will be straight up instead..

[freak_brain]

Rigid Racing,

I was thinking about buying that exact cutter. It is rated much higher (rating doesn't mean reality) than 1/2". Maybe you have something else going on that is causing the problem? That cutter is about 1,000 USD cheaper than say a miller with the same rating. We all know you get what you pay for but a grand in my pocket means alot. Your comment, eventhough I appreciate it, really changes things for me. I thought I knew what I was going to buy but now I'm not sure. How old is your cutter?

Maybe someone can help out here. Is this normal for a hypertherm 1000??

Thanks
Allen

[Rigid Racing]

Its about 5 months old. It may very well be ok for what you are doing. I was wanting to cut parts that had holes with a diameter less than half inch. That is what it seems to have a problem with. I found it better to cut out larger profiles and drill holes after. What sort of parts will you be doing?