drilling new holes into a metal CP

[Nemss316]

Ok, my control panel is made of thin metal. I just need to drill some more holes in for my extra buttons. What size drill bit will I need? I've seen a couple of different posts on this, but am wondering what the size is?

[More Cowbell]

Use a 1 and 1/8" hole saw. It's different from the standard spade bit that you can use for wood panels. It's round and has sharp pointy teeth.

[(+_+)]

Or you can use a knockout punch. Nice and very clean holes.

http://www.irvansmith.com/scart/punches-knockout-punches-c-3_54_56.html

[Nemss316]

Thanks! I'll try the 1 1/8" hole saw. I've seen some good cuts with this bit before, I just needed the size. My marquee and CP overlay are in, so i can get everything hooked up. i'll post my pics once i'm done!

[grbgemen]

i used a step bit.  after about 12 holes, the bit was dull.  really had to force it to cut the last 4.  the bit went all the way up to 1 and 1/8".

[Necro]

you put your CP overlay on before you drilled out the metal?  I'm thinking the hole saw has the potential to seriously  -up your overlay.  The punch might as well, but in my mind it seems like it would have a better chance of being successful.

[Malenko]

just a word of warning, the punch will leave the holes slightly bigger then the size indicated, especially if its a conduit punch. Also, the edges will be SHARP

[Nemss316]

no, i havent put the overlay on yet. i'll put that on once the holes are cut. Since I only need to cut about six holes, i'll use a step bit and see how that does first.

[Kevin Mullins]

quote author=Nemss316 link=topic=85881.msg901212#msg901212 date=1224705848]
My marquee and CP overlay are in,
[/quote]

He didn't say he put it ON. 

As for the metal hole saw .... 1 1/8" is the correct finished hole size, but I personally recommend a 1 1/16" hole saw due to the fact that that kind of hole saw bit tends to "chatter" causing the hole size to be slightly larger than the bit is intended. Once it chatters the pilot hole will enlarge causing the bit to "walk" a little, once that happens the outer hole saw also walks.
A half round file can take care of any little bit that may be undersized rather quickly if you use the 1 1/6" bit.
Trial fit a button in each button hole before calling it good.

Similar theory to the punch given.

Keep in mind there isn't much lip on a button, so once the hole is too big .... it's a done deal, your buttons made fit loose.

[Necro]

quote author=Nemss316 link=topic=85881.msg901212#msg901212 date=1224705848]
My marquee and CP overlay are in,

He didn't say he put it ON. 

...
[/quote]

Thought he meant in the cab .

[orion]

quote author=Nemss316 link=topic=85881.msg901212#msg901212 date=1224705848]
My marquee and CP overlay are in,

He didn't say he put it ON. 

As for the metal hole saw .... 1 1/8" is the correct finished hole size, but I personally recommend a 1 1/16" hole saw due to the fact that that kind of hole saw bit tends to "chatter" causing the hole size to be slightly larger than the bit is intended. Once it chatters the pilot hole will enlarge causing the bit to "walk" a little, once that happens the outer hole saw also walks.

[/quote]


I had this happen to me on the metal control panel that I drilled. The hole was so big that the happs buttons were to small for the hole. Luckily Willams leaf buttons fit just fine. All in all in my case I consider it a happy accident as I like the leaf buttons so much better than the microswitch ones. Also you will want to have some oil on hand to lubricate the hole saw periodically as you are drilling as it will get really hot and mess up the hole saw if you don't. Let the speed of the drill do the cutting, don't put to much force on it. I had no real problems drilling out the 1 1/8 inch holes but drilling out for the 3 inch trackball about burned up my drill and it can get away from you if you aren't careful.

[More Cowbell]

Yeah, those tiny shards of metal get red hot. Then watch out for the hunk of metal that looks like a washer that falls out of the drill when you're done. Skin-charringly hot.

[Franco B]

Lubrication

Personally I would pre drill the hole and use a 1 1/8" slot drill/end mill but you may not have access to them.

[Kevin Mullins]

Personally I would pre drill the hole and use a 1 1/8" slot drill/end mill but you may not have access to them.

Yeah, and with a two-flute end mill you don't even need to pre-drill .... but then again, you also kinda need a MILL.
 

[Franco B]

Slot drill = 2 fluted end mill

True, you dont need to pre drill but I always do with thin material to stop it from wandering.

Yeah a milling m/c is kinda a must isnt it  Saying that I have used one in a radial arm drill with a handwheel.

[Kevin Mullins]

Saying that I have used one in a radial arm drill with a handwheel.

Certainly... done it many times myself, works fine if you have an end mill that big with the proper shank size to fit the radial arm drill / drill press.

But anywho, I'm sure this isn't helping the original poster unless he has access to a machine shop of sorts.
 

[Nemss316]

Nope, not access to a mill. I guess i'll try the 1 1/16, and just file the extra space needed. I'd rather be safe than sorry, and I already have my happ pushbuttons sitting on the floor waiting to be installed.