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Square hole or round switch?

H

hammeredklavier

owner of two very cheap hi-fis
Right chaps - nothing's easy is it! - the bag of amplifier bits and bobs I have here contains a square mains switch; the modushop case I have doesn't have a suitable hole. I do not fancy trying to cut a square hole, unless anyone knows a neat tool/trick?

Anyone got a better idea than to use one of these?

https://www.amazon.co.uk/gp/product/B0743GMJRD/?tag=pinkfishmedia-21

Drilling a round 20mm hole should be easy enough!

Alex
 
This site contains affiliate links for which pink fish media may be compensated.
Oblong/square holes are best cut using a hand dye type press-tool, but are not too difficult to cut by hand, just slow.

Cutting a 20mm ROUND hole isn't as simple as it sounds - the work piece will need to be very firmly clamped, cutting fluid of some kind used, and all on a pillar drill. Oval and sort of cloverleaf shaped holes are easily cut otherwise.
A taper drill is often easier than a twist drill, but a GOOD one that holds an edge is very expensive.

Many square or oblong switches mount to round holes.
 
Vinny said:
Oblong/square holes are best cut using a hand dye type press-tool, but are not too difficult to cut by hand, just slow.

Cutting a 20mm ROUND hole isn't as simple as it sounds - the work piece will need to be very firmly clamped, cutting fluid of some kind used, and all on a pillar drill. Oval and sort of cloverleaf shaped holes are easily cut otherwise.
A taper drill is often easier than a twist drill, but a GOOD one that holds an edge is very expensive.

Many square or oblong switches mount to round holes.
Click to expand...
OK, glad I asked!

Feel free to laugh at me, but I was just going to buy one of these and set about it with my DeWalt!

https://www.amazon.co.uk/dp/B09S61RQMB/?tag=pinkfishmedia-21

I've got thick skin, what hand tool would you use to cut a square hole? Presume you'd have to drill a small hole to get started and then...?

Ta

Alex
 
This site contains affiliate links for which pink fish media may be compensated.
20mm is a BIG hole to drill hand-held, certainly if you want accuracy in placement and/or dimension, no matter the material being cut.

To guarantee at least reasonable accuracy on both, I can't think of anything but some kind of simple drill press or a pillar drill. You might get away using a hand drill, but once it is wrong..............

What you are looking for is some way to keep alignment of the drill bit and work-piece - the drill-bit is going to wander to some degree otherwise.

They will be expensive again, but all of the common non-round electrical cutouts have hand press tools available to cut them - drill a pilot hole, and then the two parts of the tool are clamped together from each side of the material being cut. They MUST be sharp and will only cut 2-3mm or so sheet. Many large diameter round holes can be cut the same way.

They all work on this principle - SagaSave 32.5mm (16-50MM) Sheet Metal Punch Hole Punch, Metal Inner Hex Hole Cutter for Q.Max, Steel Plate, Stainless Steel : Amazon.co.uk: DIY & Tools

Cutting square holes by hand - cover the area with paper tape so that you can mark accurately the shape and position of the hole without marking the work-piece. Drill as many holes inside the edge of the hole as you are comfortable with - don't get TOO near the edge. Remove the remaining waste using whatever files suit.
 
This site contains affiliate links for which pink fish media may be compensated.
Vinny said:
20mm is a BIG hole to drill hand-held, certainly if you want accuracy in placement and/or dimension, no matter the material being cut.

To guarantee at least reasonable accuracy on both, I can't think of anything but some kind of simple drill press or a pillar drill. You might get away using a hand drill, but once it is wrong..............

What you are looking for is some way to keep alignment of the drill bit and work-piece - the drill-bit is going to wander to some degree otherwise.

They will be expensive again, but all of the common non-round electrical cutouts have hand press tools available to cut them - drill a pilot hole, and then the two parts of the tool are clamped together from each side of the material being cut. They MUST be sharp and will only cut 2-3mm or so sheet. Many large diameter round holes can be cut the same way.

They all work on this principle - SagaSave 32.5mm (16-50MM) Sheet Metal Punch Hole Punch, Metal Inner Hex Hole Cutter for Q.Max, Steel Plate, Stainless Steel : Amazon.co.uk: DIY & Tools

Cutting square holes by hand - cover the area with paper tape so that you can mark accurately the shape and position of the hole without marking the work-piece. Drill as many holes inside the edge of the hole as you are comfortable with - don't get TOO near the edge. Remove the remaining waste using whatever files suit.
Click to expand...
Thanks buddy. Drilling out and filing shouldn't traumatise me too much!

I've drilled holes in metal reasonably accurately with a hand drill and cobalt bits before, but only in applications where it wasn't majorly critical. In fact, I fitted one of those mild steel green pumping station control kiosks recently, that involved copious metal drilling - nothing over 10mm though and I agree it's harder than it sounds. Used 3-in-1 as cutting fluid, just what came to hand! :-D

Ta

Alex
 
This site contains affiliate links for which pink fish media may be compensated.
Just be certain to use some kind of try-square to mark position for any square or rectangular hole - not far out looks HORRIBLE. Check with a square as you progress.

Take it slow and offer-up the switch as soon as you are close, so that you get a good close, snug fit.
 
Vinny said:
Just be certain to use some kind of try-square to mark position for any square or rectangular hole - not far out looks HORRIBLE. Check with a square as you progress.

Take it slow and offer-up the switch as soon as you are close, so that you get a good close, snug fit.
Click to expand...
Yep, that's a winner. Exactly what I'm going to do, thank you! :)

Alex
 
I would chain drill or use a gerber type multi tool with a cutting disc.

Or get a diamond coping saw blade they are used for cutting ceramic tiles, so go through anything, can get 6 or 12 inch t fit hacksaw frames or actual coping saw frame give much more clearance. This allows to cut very accurately then clean up with a file.
As said measure and mark out well if looking after the finish use masking tape and cut through it to prevent the edges being damaged, go slow
 
Agree with all of the above.

Chain drill with lots of small holes, way inside the marked size and finish by file.

Allow plenty of time, and don’t rush it.
 
How thick is the panel you plan to drill? Nobody else seems to have asked this important question yet. I assume it's an aluminium panel and not steel?

My advice will probably be a decent bi-metal 20mm holesaw, but drill the centre out with a 3 or 4mm bit first as a pilot. If it's more than say 3-4mm thick then a drill press is basically essential to get a well-aligned hole.

I know those round switches you plan to use - they need a small "key" filing to the L or R of the hole for the anti-rotation key on the switch body but that is simple enough. It only needs to be very slight, to stop it being a sloppy fit.

Square holes are a pain unless you have a milling machine, but it can be done by chaining holes near the edge and then filing out. Not much fun to do on 10mm+ thick panels though.

As said, lubrication is important. No need to use super-specialist stuff here, even duck oil or paraffin is fine. Try to keep revs down on the drill, the cutting edge of the holesaw does move pretty quickly compared to small twist bits.
 
hammeredklavier said:
Drilling a round 20mm hole should be easy enough!
Click to expand...
One would think so, but my cheap drill press and limited machining experience has led me to avoid drilling anything larger than 12mm.

For bigger holes (where the stock isn't too thick), I've started to use punches.

If the stock thicker, I'll still drill, but I'll go from the back side (e.g. the inside of the front panel). I start with a stepped bit until I get the entry point of the hole large enough to fit a fixed size bit. Then I change over to the fixed size, and finish the hole. Use lots of drilling/tapping lubricant.
 
If you chose a round switch and then pilot drill and then a step drill to drill the hole, with a step drill you don't need a drill press or anything fancy coz any battery drill do - easy solution and will work where a hole cutter will not if you already have a round hole that's too small, a step drill will center itself on an existing round cutout whereas a hole cutter will be all over the place.
For a square hole use a step drill to max (or just under max) dimension and then file it out square by hand, if the case is 2 or 3mm aluminum or steel (typical for enclosures) it's not difficult at all, but if it's titanium or 440C stainless steel (which I absolutely doubt) you might have a problem.
 
Step drill works very well - and even better if you use some cutting fluid (a spray can of CT90 is something that is very useful to have). Take it easy with little pressure and it will cut away nicely for you.

Then square out the corners using a file, or a cutting disc in a dremel type tool can work well.

In future - only buy round switches!!
 
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