Nitinol Drain Closer Idea
 

I had a thought today as I was filling the bath room sink with warm water.

Wouldn't it be nice if the drain stopper closed on it's own, a spring would default it to closed, but a Nitinol spring in the drain pipe would pop it closed once warm water hit it, so the drain stopper would close and the sink would start filling wasting as little warm water as possible.

I think a foot of Nitinol wire would be enough for a spring and it costs 50 cents per foot, so all and all it would be cheap to have as an option.

That is a pretty cool idea. For those who do dishes by hand, it seems like it would be very nice.

How would you un-stop it if its still warm? Also, if the spring is below the drain stopper, how would you keep the spring warm while doing dishes?

If you're serious about it, we could design a prototype and I can use print it out with the 3d printer I have...

My bath sink has the standard drain stopper that relies on friction to keep it up or down.

The most common use of Nitinol that I've seen is heat activated springs, when the water water turns it into a spring it can still be moved, but it would be a self closing drain, when the water was cold the spring would bend like a wire twist tie.

For a kitchen sink it might be more complicated, but I think most of the common drain stoppers could be retrofitted.

I'm not sure if any 3d printed parts would need to be made as I think simple bent wire springs could work.

I'd say go for it then. I'd love to see a working prototype.

I ordered up one of the heavier wires I could find on Ebay, one version of it said it reacts at 70F other 98F, ordered a 5 foot long piece for $12, now to wait...

https://www.youtube.com/watch?v=JKBM9my5eOA

I didn't know it was so easy to get nitinol! Time to weird out the kids with some "metal i found at the ufo crash"!

Have you played round with this yet Ryland?

The nitnal wire I bought was junk, haven't bought more, might opt for the pre made springs.