We've written about plasma cut holes before. It's one of our most asked questions..."How can I make a better shaped hole?"
If you are in a high volume production environment and have a Hypertherm HyPerformance Plasma then the answer is simple: use True Hole. True Hole will automatically apply the right parameters so you get a perfect hole every time.
For the rest of us, there's good news and bad news. The good news, it's entirely possible to cut out a nice hole using plasma. The bad, it's going to take some trial and error.
Before we share some best practices when it comes to hole cutting, let's first talk about what makes a good hole. Generally, when people complain about plasma cut holes it's for two main reasons: 1) The hole is tapered (i.e. the diameters at the top and bottom of the hole differ) similar to what is shown in the simulated photo below. 2) There is a notch somewhere along the edge of the hole as demonstrated in the following photo.
If you've ever had to cut out a hole, chances are good these photos look familiar. Other problems include too much dross or a completely malformed out-of-round hole. Generally, though the big issues are the two mentioned above.
How do you fix all of these hole problems? Glad you asked. Hypertherm Applications Technology Manager Jim Colt has put together a presentation with lots of illustrations and photos to walk you through hole cutting. That presentation is available for free download at http://response.hypertherm.com/betterholes.
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