Cutting the hole for a slide switch
 

This trick has saved me a lot of time and damaged panels over the years (I used it again today which is what reminded me of it), even if it does involve 'wasting' a slide switch.

When I need to make the holes for a normal type of slide switch, I start by dismantling a switch of that type (I only use a few types of such switches, so I keep the dismantled bits from one project to the next). Normally you just have to bend up the tabs on the back and remove the insulating contact plate and the slider/moving contacts. The part you need is the body.

Now position the empty body on the back of the panel and mark/drill one of the fixing holes. Screw the empty switch body to the panel with that hole, then mark and drill the other fixing hole. Screw the body in place with both screws.

Now drill as large a hole as you dare in the rectangle where the slider will go, and file it out using the body as a template. You will then find that your complete switch fits properly and that the rectangular cutout is neater than you could probably make without the template.

Re: Cutting the hole for a slide switch
 

Excellent tip. I usually do it by trial and error, but this method sounds much better.

Re: Cutting the hole for a slide switch
 

I cannot say I have ever had to make a hole for a slide switch as I have a draw full , your method will be the way to go , Excellent idea. Mick.

Re: Cutting the hole for a slide switch
 

Mick, you have a drawer full of holes? Can you send us all some rectangular ones in various sizes? It will save all that filing.
What's the best way to store them, I've tried poly bags but they fall through.

Re: Cutting the hole for a slide switch
 

Mesh bag.

The holes do get a bit tangled up though.

Re: Cutting the hole for a slide switch
 

This is indeed a useful tip: I've got a collection of old/scrap components like this which I use as templates.

Another useful tip: if you're throwing out an old, stripped-for-spares radio chassis, cut out the plate (a plunge-saw is ideal for this) that mounts the tuning-capacitor and keep it with the capacitor - then when you come to re-use said capacitor in some future project you've got the hole-drilling template ready and waiting.

Re: Cutting the hole for a slide switch
 

Keep 'em in Blackburn, Lancashire 8-)

(Maybe along with your spark plug gaps, long weights, magic smoke and the rest......)

Re: Cutting the hole for a slide switch
 

I think your method certainly saves some time, albeit sacrificing a switch.

For all of my panel work, hole marking etc I use a vernier dial caliper which has a 0.01mm scale. Measure from the slide switch sample the required rectangular cut out geometry with the aim of making the rectangular hole just a little bigger than the one in the actual switch body perhaps 0.25 mm all around. Then measure the hole centers with the caliper, and generally they turn out to be some exact spacing, (often these are metric or imperial spacings, mostly metric as many slide switches are Japanese made)

Then I mark the panel gently using the edge of the micrometer blade often using the side of the panel as a reference edge for the other blade, to set the switch axis and position and hole spacing and the marked rectangle, buy subtraction of the spacing from the panel edge with a calculator handy.

Then under high magnification and light I mark the screw hole centers with a hand spike right on the cross of the lines, countersink those initially with a 1mm drill, before drilling two 1.5mm pilot holes. Generally I can get these with less than a +/- 0.05mm error.

Then I drill inside the rectangular hole and file the rectangle out with a precision file set, protecting the panel from abrasions on its bottom surface with plastic tape, then put 1000 grade paper around a small file and smooth the file marks away from the cut edges of the rectangular hole. No matter how well a panel is marked out, the hole centering with respect to those marking has to be good too.

For steel panel I also always paint the cut edge.

But of course, it is a lot of work & time to do it well, which I think is why most go for round hole switches for home projects and avoid slide switches!

Re: Cutting the hole for a slide switch
 

It may even be possible to reassemble the switch afterwards?

Re: Cutting the hole for a slide switch
 

Indeed it is so for most of them use a bendy tag assembly, they don't take two or three attempts though.

Re: Cutting the hole for a slide switch
 

Another issue I see with re-using the switch body is that when you file out the hole, likely you will end up filing away some of the inner perimeter of the rectangle in the switch plate, at least filing off the electroplating (these are usually steel) so then it would rust unless it was painted.
But if it is a common garden switch and you have lots of them, it hardly matters to use one as a template so it is a good idea that saves time and gives a neat & tidy result.

Re: Cutting the hole for a slide switch
 

Brilliant, simple, tip !
Takes a Genius to come up with it though. Well done. I shall be using this method from now on.
Many thanks.

James.

Re: Cutting the hole for a slide switch
 

Whatever type of holes you have in your parts bins, make sure none of them are Black!!!