DIY membrane switch

[ignotus]

Hi all,

I'm in the process of building a DIY 3-zone cymbal and came up with a way to make membrane switches that work in much the same way that purchased ones do. I had bought some but they were the wrong diameter -I'm making a 14" cymbal and they're for a 10"- and then there was the issue of the bell, as the switches I bought were just for the outer edge. After quite a lot of fiddling around I decided that the ones I'd bought weren't going to be suitable no matter how I modded them, and having seen what they're like inside, I decided to try my hand at making some, and it turns out it's quite simple and you can make them whatever shape and size you want. Ok, so here goes:

First, a pic of what a commercial one looks like inside:

membrane switch open.jpg

So, the materials needed are:
- An old mylar drum skin
- Double-sided tape (the thin stuff, no foam)
- Aluminium foil
- The netting they often sell oranges or lemons in; more on that later.

First, cut out the shapes you want from the mylar head:

mylar strips.jpg

Then, cover one side of each with double-sided tape and stick on the aluminium foil, making sure there are as few wrinkles as possible, though if they're not too big it's not a problem. Leave some excess foil to attach your wires later.

with_foil.jpg

Next, apply a thin strip of double-sided tape around the outer perimeter of both parts:

with_double_tape.jpg

(Continued in next post)

[ignotus]

Now, take the netting (mine came from a bag of oranges) and place it on top of one of the parts, stretching it out a bit. This net is made with very thin, flat strands of plastic. Press it against the double-sided tape to keep it in place:

with_net.jpg

Next, stick the other side on, and trim the excess net around the edges. Attach wires to the foil tabs left earlier, test with a multimeter and you're done:

switch_finished.jpg

I first made a smaller, rougher prototype and beat the living crap out of it without anything protecting it, and also bent it back and forth repeatedly (not a real life scenario but the idea was to see how it stood up to severe abuse) and it still worked fine; I'll have to wait and see how it lasts over the long term. You can also bend it into a curve (e.g. for a bell) and it still functions normally.

I originally intended to use this sandwiched between two plastic practice cymbals but I wasn't very happy with the result - it was more sensitive than the switches I'd bought (my main gripe with them), but I found that the downside of a more sensitive switch was that it got triggered with bow hits too, so I had to rethink my approach. Right now I'm testing a different method; the switch goes on top of the cymbal, but is made as follows: foil and net is stuck directly to the cymbal and the top of the switch is 1 mm sheet rubber that is also covering the rest of the cymbal. The profile of the switch is so small (less than 1 mm) that you can barely tell it's there and it's very sensitive. Will post here to tell whether it works well.

[privatex]

You're definitely overcome standard ideas. I like this great approach, so simple but powerful, must try it asap.

[ignotus]

Just a little update to show you a variation of the idea above I'm working on:

360_switch.jpg

The foil and netting is stuck directly on to the cymbal. The whole cymbal surface will be covered with 1mm rubber sheet, finished off with 4D carbon vinyl wrap and with foil in the appropriate areas underneath to make the other half of the switch. Did some tests yesterday and it was quite promising. I never liked the idea of DIY switches on top of the cymbal because they were ugly and bulky, but this will be totally invisible once covered. And as you can see, triggering should be 360º.

[airflamesred]

Ah, this is a bell switch?

[ignotus]

Bell and edge.

[privatex]

Last night I made one switch and it works very, very good. Now there's no differences between fabricated and diy cymbal pads. Everyone can easily make some good quality e-cymbals. Nice job!

[stefan1982]

I'm very interested in this.. Could someone write a step by step tutorial how to build such a thing and how to wire things correctly? It looks really nice and seems to be the _only_ way to go, if you want something good and reliable.

Regards, Stefan

[ignotus]

What exactly do you need help with? If just using an edge switch, one wire goes to ring and the other to sleeve. If you're using two (for a switch/switch/piezo 3 zone cymbal), the bell switch is wired as per above, and the edge switch too, only the wire going to ring has a 10k resistor so MD can distinguish it from the other switch. If you search the forum for "Yamaha style 3 zone wiring" you should be able to find wiring diagrams.

I've put my build on hold until I receive some adhesive copper tape. It works with tin foil but it's a bit messy and after further testing tin foil tends to degrade - so my recommendation is to use copper tape instead.

[stefan1982]

Now that these DIY membrane switches are used for quite some time, could you elaborate on how they seem to hold over time?
So, are they still working as good as at the beginning?