I am flushmounting my taillights and i only had a 4.25" bit to cut the hole. ineed it to be 4.5" how should enlarge it. i've been going at it with my dremel with the grinding bit. but grinding that much on the steel and diamond plate is a pain anyone else have an idea.
a plasma cutter would make short work of it, but you could try something unheard of....getting the right tool???
if you can find a place that has the right size hole saw, im sure for a few $$$ you could borrow it or have them do it for you.
1. You've only got 1/4" to go.
2. The metal is failrly light.
a. Fine tooth Hack saw blade.
b. Permanent Marker.
c. A pair of locking pliers.
4. Take a piece of cardboard and cut it the size of the hole you need to make.
5. Center this piece of cardboard over the existing hole.
6. Use the marker to trace around the cardboard.
7. Use the hacksaw blade to make cuts from the inside of the hole to the inside of the line you made in step 6.
8. Repeat step 7 every 3/4" around the hole.
9. Use the locking pliers to lock onto on of the cut pieces and work it back and forth.
10. The metal will fracture and you'll be able to pull it away.
11. Repeat steps 9 & 10 and remove all the pieces around the hole.
12. Dress up the hole when finished with a hand file or a drill mounted grind stone.
See.. easy as pie! [img]images/graemlins/grin.gif[/img]
First I always cut a test piece in cardboard or scrap plywood to test fit. Both are a lot cheaper than a Jeep body-oh well too late [img]images/graemlins/tongue.gif[/img]
I have had to enlarge holes before and here is what I do:
1. Buy the right size hole saw.
2.Clamp a piece of wood or steel across the hole-in your case probably a 1"x3" piece that goes through the center of the hole.
3. Mark the center and drill a hole there for the correct size of your arbor into the new 1"x3".
4. Use your new hole saw and the new center hole will hold it in place while your are starting your hole saw.
Last time I found myself in same situation (I needed a 4" hole and only had a 3.75" saw), I was able to mark the hole and knock it out with a carbide burr and die grinder. If your Dremel has a ¼" collet, you can pick up a burr for a few bucks and make quick work of it.
You can use a Varibit. I used one to enlarge the hole for the Blazer heater motor upgrade.Took just a few seconds to make the hole bigger.It's not sold for use as a die grinder bit, but it cuts the crap out of sheet metal.You could just buy a die grinder bit and use it in your drill,would be alot cheaper than a Varibit.