Will a plasma cutter mess up a power coat finish too bad?

Hi,

I will have an arcade control panel (for joysticks / trackball) that is already powder coated that I need to drill about 12 holes in...

I've had another thread going "Re: Drilling metal control panel advice..." which so far has indicated I should consider:

  1. Punching out the holes I need which may not work great because I'm not sure how thick the panel is, but it might be as much as 1/8" mild steel.

  1. Or using a single point hole cutter, but this may or may not work because my drill press only goes down to 580 rpm at its slowest...

BUT, I spoke with a guy today that says he has a plasma cutter that might do a good job as well. He wasn't real sure how it would affect the powder coating because it is water cooled or something like that. Does anyone else have an opinion about whether I should try this or not?

Thanks,

Alan

Reply to
SA Dev
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The plasma cutter has problems starting holes, and certainly will affect the finish, as it leaves a burnt edge. Laser may work somewhat better, but waterjet is probably the best way. Having said that, are the holes circular? If so, then the right tool is probably a single point cutter in a nice and rigid drill-press.

Powdercoating after you do the holes is generally easier, as that way you can use practically anything.

If it's one or two off, then I'd tend to think about simply chain drilling the bigger holes, and using a nice sharp file (downwards into the powdercoat) to smooth them off. A jigsaw (with the powdercoat down) may also be of use.)

Reply to
Ian Stirling

Hi Ian,

Yes. I need QTY 10 of 1 1/8" holes and a single 2 1/4" hole.

Yes, I found one at Lowe's. But my problem is that my drill press can only be adjusted to go as slow at 585rpm. DeepDiver was telling me that I would need to go much lower, around 100rpm. What if 585 is my only choice? Would it work?

Thanks a bunch,

Alan

Reply to
SA Dev

Sorta depends on how good of a dancer you are (:

Reply to
Jim Stewart

For some reason I haven't seen this article, so I'll reply here.

With HSS cutters in mild steel, you can go around 60cm/s without rapid blunting due to overheating.

At 600RPM, 10 revs per second, so the maximum circumference is 6cm. That's a diameter of around 1.8cm, so it's not a good idea even for the smaller hole.

For the smaller hole, it may work more or less OK, though go blunt fast. For the larger one, it may cut one or two holes, if well lubricated, if the drill-press has the torque to keep it spinning.

A few 1cm holes round the edges, and a file is a way to make sure that it'll work.

Reply to
Ian Stirling

Hi Ian,

The drill press is just a cheap mini drill press, only down to 585 rpm at the slowest :(

What should I use for lubrication?

If the HSS bit goes dull, can I resharpen it easily?

You lost me, I don't understand...

Thanks,

Alan

Reply to
SA Dev

As someone who's made more than a few holes in arcade game panels, I'd say use a chassis punch (like Greenlee). Unless you're having a panel custom made (in which case, specify thinner steel), every panel I've ever seen responds well to a chassis punch.

Buy a decent one, you'll have it for life.

Reply to
Mark

Mark,

Yes, of all the methods I've been hearing, I agree that a Greenlee punch is probably the best as long as the CP is thin enough.

Do you know of any place that will rent these? To buy them both it will cost ~$150 shipped and I don't need them long term, so I would try to unload them on ebay to recoup some cost when done.

Thanks!

Alan

Reply to
SA Dev

Arrange a bucket underneath it. Cutting oil is ideal. A spray of WD40, or even a constant flow of water (ensure none goes through any electrics, and dissasemble and clean afterwards.)

With a diamond hone is probably the easiest way.

Drill several small holes inside the diameter of the large hole, so that they almost join up. Join them up with a hacksaw. Finish the jagged shape using a curved file up to the edge of the hole you want. This can give as good a finish as you want, in not much time.

Reply to
Ian Stirling

It seems that most of these run too fast for the largest size drill bit which fits the supplied chuck to be used in steel. :-)

It is possible to modify it with an extra pulley and shorter belts to get two stages of speed reduction (and increased torque). But this will add another project to your list, instead of directly solving your original problem.

But -- if you're interested in the basic principles -- get a third pulley similar to the two already on the machine. Invert the one on the motor, so the small end is pointing in the same direction as the small end of the one on the spindle. Between them, mount the extra pulley with the big end in the direction where the smaller ends are on the other two. Mount it on an arm which pivots to all the distance between that pulley and the other two to be tuned. Now, get some shorter V-belts, and run one from the big pulley step on the spindle to the small step on the added pulley. Then run the other belt from the big step on the added pulley to the smallest step on the motor's pulley. This will give you the slowest speed possible from this setup --

*and* the maximum torque. Whether the quill's spline will be up to the torque remains to be seen.

What are you cutting -- aluminum? Steel? Unobtanium? The right lubricant is a function of the material.

Yes -- if you have a bench grinder.

Mark out the circumference of the desired hole on the panel (probably the back would be the best bet), then drill holes within the border marked out, with a more reasonable sized drill -- perhaps with a step drill -- and use a file to join the holes (which will drop out the center disk being removed) and then move out to the marked-out edge using a half-round file. It is slower than the *right* power tool, but you don't have the right power tool, so this is one of the other ways to work. I would suggest hearing protection while filing the panels, though you can damp the sound quite a bit by clamping it between two

2x4s in a vise or with C-clamps

There are other tricks which will work for thinner metals, if you have an air compressor, as there are nibblers which will work rather quickly, up to 1/16" thickness, but I think not for 1/8" thickness.

But to me -- the ideal tool for the task would be a boring head in a milling machine -- which you don't have, unfortunately.

Good Luck, DoN.

Reply to
DoN. Nichols

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