Tips for drilling a blank control plate?

[Boolywho]

I'm looking for some tips and advice...

I've got a blank plate from GFS, like this one here:


I'm planning on drilling three holes in it, two for some Alpha push/pull pots, and one for a Switchcraft LP-style switch:


I'd like to have the switch in the middle of the control plate, positioned between the two pots.

I've already masked both sides of the blank plate, drawn out a center line, and marked the desired locations for each of the components on that center line.

Here is the current state of the plate:


So can anyone tell me the best way to go about drilling these holes? Can I just use a normal drill bit with a drill press? If so, does anyone know what sizes I should use for each of the components? I also have a metric step drill bit, should I use that instead? If using a step drill bit, do you have to drill an initial hole first to then be reamed out by the step drill bit?

I'm a total drill press newbie. Do I mount the plate on a piece of wood and then just drill things out with that as a base and not worry about the wood underneath?

Is there any sort of jig that people use to totally ensure that all the hole are on the same line? Does everything need to be clamped down before I drill?

Is there anything else that I should be aware of while doing all of this?

Thanks for all your help!

[davmac]

I don't know if it the correct way of doing it but the way I'd approach this would be to first draw round the control plate onto a piece of MDF, and then using a small drill bit (2-2.5mm) drill pilot holes for the three holes in the MDF.

I'd then use this template to do a test on a second piece of scrap - use the small drill bit to mark through the first into the second, and then drill the second out to full size holes. You can then test fit the components into the MDF to check hole size and layout accuracy. Once you're happy with it you can then use the first piece as a template for marking your control plate with the small drill bit.

I'd attach the template to the control plate with double-sided tape.

Once you've marked the hole centres, take the template off and finish drilling to the final size. Then use a larger drill bit to slightly chamfer the hole edges (front and back) and get rid of any burrs.

Your drill press is the perfect tool for all of this. Unless you're happy dealing with a rapidly spinning piece of metal near your fingers then clamping it down tight is an absolute must. I've got a small clamp-on mini bench vice which I find perfect for this. But you may have to improvise something (double-sided tape down to a piece of scrap and clamp that down to the drill press table?). For drill bits, I'd just use standard HSS bits, but I don't have a stepped bit.

For the hole sizes, do you have any calipers available? If so use them to measure the diameter of each component. If not you should be able to get pretty close by holding up the various drill bits to the component, against the light, and picking the size that is just fractionally larger.

[Boolywho]

davmac,
I do have a some digital calipers, and I've measured everything out, but I'm still at a loss to know how much "fractionally larger" the drilled holes should be than the components that will be going into them. Maybe you can fill me in on this?...

Thanks for your help!

[davmac]

Well on the first attempt, in the scrap wood, I'd go for the exact size and check the fit. As to what I mean by "fractionally larger" - just enough for the component to snugly fit through the hole and definitely less than 1mm. Remember you'll have the washer and nut that will totally cover any small gap. This is why, for me, the test on scrap is the important part of the process. It lets you get everything just how you want it with out damaging anything.

[Ricky D.]

Size the hole for about 1/32" clearance. Whatever that is, you could compare to the holes in the flat washers that came with the parts.

Once you layout the centers, centerpunch before drilling. That helps keep the bit from wandering. I would drill the first hole about 1/8", then enlarge in roughly 1/16" increments to get to your desired diameter.

Clamp your workpiece securely or don't even try this. Otherwise, if the bit grabs, you'll get hurt!

This is basic stuff. Take your time and be careful, it will turn out just fine.

[Jack Wells]

If I were doing this, I'd probably screw the plate down to a piece of wood then clamp the wood.

[Tom Pettingill]

Originally Posted by Jack Wells

If I were doing this, I'd probably screw the plate down to a piece of wood then clamp the wood.

Very good advice! Bits can catch when drilling thin stock and you want things clamped and secure. Bad things happen when things are not "bolted down".
Step bits work very well with thin stock and would be my first choice. Larger sized regular twist bits tend to grab more and make an oblong hole in thin stock.
Use a center punch to mark the spot and go strait at it, no need to drill a pilot hole with a step bit.

[Bolide]

You'll want to debur after. Some auto parts and hardware stores have pretty slick deburring scrapers in stock, if you can't find one locally a scraper can be made by taking an old triangle ("three-square" ) file and grinding the teeth off leaving hollow ground surfaces on the three faces.
Be sure to cool the file frequently as you are grinding so you don't take the temper out.

The ready made scrapers are are easier to use than the hand made one.
[for illustration, no affiliation or endorsement
http://www.toolstoday.com/p-5657-car...e-scraper.aspx
]
but using the hand ground scraper is not difficult; The store-bought ones show their value when you have to debur dozens of holes.

If you ever drill stainless there's a good chance that the drilling will work-harden the metal so much that a scraper won't cut it; in that case you will want to use a cone shaped or round stone. Most hardware stores have these with arbors that will go in a drill chuck, or you can simply work the stone by hand.

[Boolywho]

Well, I went ahead and drilled the plate using a step drill and a drill bit:


It went alright. I tried to punch in a guide divot with a hammer and a screw so that the bit wouldn't stray off center but things still ended up a millimeter or two off of center for each hole.

It's good enough for me though, so I'm not too worried about it.

Anyway, my 10mm holes for my Alpha pots are just a bit big so that the pots have a little bit of wobble room. Can somebody tell me how to amend this so that the pots stay put without any play?

Thanks for your help!

[mike shaw]

Maybe you can use some plastic / nylon tubing or shrink wrap? Just trim away the excess with an X-Acto knife.

[JCSouthpawtele]

I cover the control panels of amps with the blue painters masking tape so I do not scrape the shiny finish when adding pots in mods. I like the idea of mounting the plate onto a piece of wood, a scrap piece of plywood could do. and then C=clamp down the scrap piece of board as to not scrape off the blue tape you covered the nickel/chrome finish off the face. And yes a smaller pilot hole then go bigger to finish.

[vlada]

great ideas. i`m making control plates myself these days so it will be helpful. tell me please what diameter switch holes are?

[mellecaster]

Originally Posted by vlada

great ideas. i`m making control plates myself these days so it will be helpful. tell me please what diameter switch holes are?

There is no Standard diameter...measure the ones you plan on using.