Drilling a Chrome Control Plate

JayM · #1 05-02-2007, 01:20 PM

I need to enlarge the pot mounting homes in a chrome plated control plate to accommodate the larger diameter of the CTS pots.

Does anyone know the best way to go about this to avoid (or minimize) flaking off the chrome plating?

If this wasn't plated, I'd just screw it to a scrap board and run the drill bit through it, but I'm afraid that would flake off the plating on this one.

So what is better:
Taping the holes or not?
Drilling fast vs slow?
Reaming out the hole with a file rather than drilling?
Using a conical stone in the drill instead of a bit?

Anyone done this successfully before?

x_Zero_x · #2 05-03-2007, 02:08 AM

there is 2 ways of doing this..

1) place it good part down on a peice of wood and drill from the bottom

2) drill a tiny hole and file it to the right size..

i dunno.. just my thoughts..

x_Zero_x · #3 05-03-2007, 02:15 AM

ALSO make sure you use a center punch so the drill bit doesnt wonder while you start the hole.. also slowish speed with steady pressure. using a bit of oil will make a cleaner cut for you

JayM · #4 05-04-2007, 01:35 PM

The plate already has holes, I'm just enlarging them a little to fit larger diameter pots.

I'll try the oil suggestion.

Thanks

pkr2 · #5 05-04-2007, 07:13 PM

The chance of the plating flaking off from enlarging the holes is practically nil.

I suggest using a round file (Rat-tail file). Your idea of screwing the plate to a board is a good one. Just drill a hole in the board a bit larger than the finished hole, center the hole in the plate over the larger hole in the board and file away. mount it finished side up just to be on the safe side.

Using a drill bit may not work as well as you think. A regular bit in a hand drill will often produce a hole that has an irregular triangular shape. The plate mounted in a padded jaw drill press vice and using a drill press is more likely to work well. A Uni-bit would work well in a hand drill but they are pretty pricey for a one off job.

If you can get hold of a tapered reamer, they work well and are quick.

bassman275 · #6 05-04-2007, 07:19 PM

Drill press w/ tapered reamer,oil,slow speed.In any case secure the piece and apply the tool.

Rattman · #7 05-04-2007, 10:54 PM

Yeah... I like pkr2's suggestion about the "unibit".. The best tool investment I made in 2006 was buying my first unibit. It makes the most beautiful, clean holes in sheet metal and plastics. I have no fear now of making modifications on amps chasis or pickguards, etc. However: I've never done any cutting with it on chromed-plated steel... maybe a bit of oil might help to prevent flaking.

JayM · #8 05-07-2007, 12:36 PM

Thanks for the advice, I think I'll look for a Uni-Bit. I can always use more tools.

Thanks.

ducatiman · #9 05-08-2007, 05:53 PM

yes, i believe i have done this with success in the past.

IMHO - if you're just enlarging existing holes a bit, i'd go with the tapered reamer BY HAND just a bit at a time. you're less apt to make a mistake, egg out the holes or go too far. a bit at a time, stop, trial fit pot, do more if needed.

--------------duc