Picture of How to Use a Plasma Cutter
Using a plasma cutter is very convenient and fairly easy.  The benefit is that "freeform" cuts can be made to metal based on guiding the cutter.  Since this machine works by directing plasma through the creation of a circuit, a ground clamp is necessary, much like welding. 

This instructable is strictly to show practical operation of a plasma cutter.  For an example where this operation is demonstrated to make something, refer to Sheet Metal Flower to Practice Plasma Cutting and Welding.

I made this at TechShop Detroit (www.techshop.ws).

Step 1: Choose Work Location

Picture of Choose Work Location
Since we plan on cutting metal, placing the metal on a surface that is safe and allows for freedom of movement is critical.  A "grate" or  similar surface that functions as a table is perfect.
kidharris2 years ago
The air has to be as dry as possible, dryers in the line are a necessity. The water in the driers should be bled off before turning on the air.
newdetroiter (author)  kidharris2 years ago
Thanks for pointing that out.
rickster4542 years ago
this is SOOO cool., I can't wait to get one=!!
kidharris2 years ago
To turn on the air valve, turn the handle from perpendicular to inline.
newdetroiter (author)  kidharris2 years ago
Fixed, thanks for your feedback.
vpatui2 years ago
Could you have mixed up the photos showing "air on" and "air off"?
thewmas vpatui2 years ago
most likely, never seen a ball valve on, at a right angle
newdetroiter (author)  thewmas2 years ago
Yup, and it has been fixed.
newdetroiter (author)  vpatui2 years ago
I did. Thanks for pointing it out, I appreciate the feedback.
dingonv2 years ago
I just need to double check you on this. I have never seen a valve of that type that is OPEN when the lever is perpendicular to the pipe.
newdetroiter (author)  dingonv2 years ago
Thanks for double-checking. I have edited the instructable and appreciate your feedback.
I don't want to sound negative, but the same instructions could be applied to a toaster! Switch it on, use it, switch it off.
I think most people could guess all the steps for just about any appliance?
How about something on the actual cutting?
Starting from an edge/hole or how to pierce to start
What distance to hold the torch from the material and the torch angle
Smoothness and speed of movement
How to decide what current and airflow are appropriate for a job
The importance of a good quality, dry air supply
To name but a few.
I've only found the above by trial and error - an instructable giving accurate advice or a methodical way of deciding on the options would be very valuable, not least to me!
Most texts I've found kind of assume you know how to do the actuall cutting and like the above concentrate on plugging the machine in to the wall or really advanced cutting.
I'm sorry, but I agree... How did this end up in the newsletter? I was looking forward to getting some tips & tricks about using a plasma cutter beyond the on/off switch and an odd explanation of ball valve functionality. I love the idea of learning about the use of a plasma cutter, but this isn't it. Also, if you reference another instructable (Sheet Metal Flower to Practice Plasma Cutting and Welding), why not just add a link to it? Make it easy for readers to find your cool 'ables. Cool flower...

newdetroiter (author)  GeeDeeKay2 years ago
Thanks for the suggestion. I have added the link.
ddemayo2 years ago
It is not the posters fault that they chose her Instructable for the newsletter. Give her some credit I understand she did not provide much, but for some people this actually does help them. I know its not much, but this is also her 4th able and maybe she is going to continue posting as she learns more. Maybe she just started cutting and this was new to her. As for the air she does need to edit that it is a dangerous confusion. We are a friendly community please comment with constructive critiques rather than bashing that she did not give enough.
Captain4432 years ago
Well that wasn't very informative at all.... go back and try it again
Phil B2 years ago
I learned the hard way that cuts should begin from an edge on the metal, not from the middle of the surface. Also, could you say something about how far to hold the gun above the surface and how to know if travel is too fast or too slow? Thanks.
Lemon Phil B2 years ago
With practice, I have found that cuts can be started quite predictably by piercing the metal at a shallow angle first - maybe about 50 degrees or so - and then 'rolling' your wrist and the torch jet to the regular cutting position and continuing as normal from there. Spatter can spray back at you (and has for me in a few cases) if you try and pierce metal holding the torch perpendicular to the surface. However I still drill a small hole for starting the cut on thicker pieces just in case.
newdetroiter (author)  Phil B2 years ago
Good point! I addressed them in my recent "Sheet Metal Flower to Practice Plasma Cutting and Welding" one.
rayj00072 years ago
I believe the pictures sequences for "turn the air on" and "turn the air off" are in the wrong order. On every ball valve I've ever seen, the handle position perpendicular to the flow through the valve is the closed position and the handle position parallel to the flow is the open position. I must agree with simonrafferty, the instructions have no real information about using a plasma cutter to cut metal.
Totally agree - whether the handle is correct or not in real life in the shop in question, posting the photos like this is just dangerous. Just to check I am not insane, I did a quick search and all I find is confirmation that parallel to pipe is open, perpendicular is closed, e.g. http://www.archtoolbox.com/materials-systems/plumbing/105-plumbingvalvetypes.html

This needs to be edited!
hygicell2 years ago
I have never seen a ball valve which is closed in the line position and open in the perpendicular position, it is illogic and confusing, throw the thing away
sconner12 years ago
I was expecting some technique, rather than just "plug it in and turn it on"