Need to drill a 3.5" dia hole in my ARB bumper (1 Viewer)

[canman]

I'm in the process of modding an ARB bumper for my LX, and last night while trying to drill a 3.5 hold for some fog lights, I seemed to have buggered up my brand new Dewalt drill chuck and the threads on the hole saw bit. The Bosch drill I was using was also starting to smoke so I called it quits. I couldn't tighten the hole saw completely on the centre drill chuck because the two pins wouldn't line up with the holes in the hole saw. Should I not be able to drill a 3.5" hole using this method with a hand drill? I did some holes previously using my drill press with no issues.

 

[steffan]

I used my hand drill to drill 3.5" holes in 1/4" plate for my skid plate. Worked fine - I've done a bunch of holes with the same hole saw and it's still good - I think it's just a husky or Milwaukee - nothing fancy. The key is go slow and use lots of oil

 

[pb4ugo]

I think the pins are what keeps the hole saw from spinning, not the threads.

 

[canman]

I was trying to go slow but it was very difficult to keep the speed down with this particular Bosch drill. I always use cutting fluid, but the bumper face was on a bit of an angle, do if was difficult to keep the drill perpendicular to the bumper face. The hole saw and was wandering a bit, but that is normal. Also, one of the pins fell to the ground while I was drilling. At first I thought it was from the drill.
I'm pissed because the centre drill was brand new out of the box, and the hole saw was still good. I'll try to return the centre drill to Home Depot on the weekend. I might try my plasma cutter using a little jig tonight or tomorrow.

 

[canman]

Was ready to do this on Friday, but forgot that my buddy had borrowed my plasma. I made a small jig using a part (swivel base with wheels) that I had purchased when I ordered the plasma. Hole was not very round even with the jig, but a lot of grinding got it pretty close.

 

[Patineto]

It may not be perfect, but it works really well..

Ig you are using a hand drill swindle the hole saw cutter about 1/8" height or even less, that permits that only and few of the cutter tette to do the job, just keeps swinging the drill until the cut is completed..

Rat file is necessary for most of this cuts and the hole will be a little bigger than the one stated on the cutter.

 

[PAToyota]

I couldn't tighten the hole saw completely on the centre drill chuck because the two pins wouldn't line up with the holes in the hole saw.

As mentioned, it is the pins, not the thread that keeps it from spinning. I tighten mine up on the threads, but then have to back it off a bit to line up the pins.

Another trick is to cut a piece of wood at an angle and clamp that to the metal so that you can start the hole perpendicular in the wood. Then, as it cuts into the metal it has a “form” to keep things aligned.

 

[canman]

Finished up the bumper last year.

EP 9.0 Superwinch install on ARB