Making a puller switch

My project needs a handle you can give a good tug on, to trigger a button press. It looks like this:

puller

What I have (and it works) is a button protruding out the back of the case with elastic wrapped around it held together with a piece of wire. It’s not very elegant, and I expect it will break a lot. What would you do, to give the firm-but-a-bit-springy feel I’m looking for?

I have a few limit switches, and a box of springs, even a strain gauge somewhere…

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OK, this is probably better than the elastic…

pullerspring

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Hi Colin,

That’s generally the right idea, although I’d add an end-of-stroke limiter, which could be just another screw. That stops you pulling the microswitch lever past its fully activated position.

You can even employ one of these antique babies. I’ve used these (specifically the Clipsal version) in the past, and to change it from toggle to momentary action you only need to remove an internal spring.

- Greig.

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