nebula Posted December 2, 2008 Report Share Posted December 2, 2008 Like many here, I like the idea of using rubber buttons for on-the-fly, live programming. Love it or hate it, the Monome has made a splash ... its rubber buttons are ergonomic by virtue of the materials used, rather than its minimalist design. I have an Electribe ER-1 which just feels awesome under the fingers, so I want to build a percussion sequencer using MB-808 firmware and rubber buttons. I have already started on panel layout, and I have some nifty ideas for how I'm going to put this whole thing together, but from what I've seen. making your own rubber buttons is entering into no-man's land. There have been one or two efforts from people here on the forum which have generally been abandoned.So ... here's what I've done so far: I used "GE Silicone II" which is a high-grade bathtub caulking. I chose it only because we use it a lot at my work, and I thought its rubbery consistency would translate nicely to panel buttons. I created a mold by drilling 11/16" holes in a piece of aluminum, about 3/16" thick, then putting a piece of textured, powder-coated steel beneath it, and fastening tightly with metal screws. This left some nice little wells to fill with silicone, which would be shaped like round buttons when extracted. The metal was from the scrap bin at my work. The extracted 11/16" buttons would be just slightly smaller than the 3/4" holes I would later drill in a panel.In order to allow for a button membrane base, I suck a couple of tie-wraps (a.k.a. cable ties / zip ties) down at the edges of the mold with hot glue. This way I could fill up to the top of the tie-wraps and scrape off the excess with a knife.Prior to squirting pouring in the silicone I sprayed the whole thing with "Pam" cooking spray. As I later learned, this stuff does a decent job of preventing the silicone from sticking to the mold - mostly.I allowed the stuff to cure for about a week and a half. As it turned out, this was not long enough for the silicone deeply inside the buttons to harden. When I pulled everything apart, the button tops were still gooey. As a result, the tops of the buttons are pitted and bumpy. But the entire molded piece of five buttons is remarkably sound - I can bend it and manipulate it as much as I like, and the buttons have a solid but pleasant rubbery feel. Since I used the clear silicone, light passes through it pretty well. I will be able to light up each button with two bright LEDs. And I plan to put a 6 mm tactile switch (100 gram force) centred beneath each button.This was my experiment. The next mold I make will be to fit my panel.Of the pictures I took, the ones I'm attaching here are the only ones that make much sense. Quote Link to comment Share on other sites More sharing options...
cimo Posted December 2, 2008 Report Share Posted December 2, 2008 hii ve gone this way already, are you aware that after the first layer will dry up, the inner part of the silicone will never get any air, hence won t dry ? (never), it s like if it was still in the can.That s why we should use bicomponent silicone, which cures chemically.But, you can try to do it step by step, like first filling just a bit of the moulding, let cure, add some more etc etc, that may work.Simone Quote Link to comment Share on other sites More sharing options...
nebula Posted December 2, 2008 Author Report Share Posted December 2, 2008 My next mold will have the buttons on top, and I will drill 1/16" holes through inconsequential parts of the mold to get a bit of air to it.I am of course completely prepared to fail, so do you have any ideas where I should get bicomponent silicone? Or is there something I could use as a hardening agent for the silicone I'm using? Quote Link to comment Share on other sites More sharing options...
cimo Posted December 2, 2008 Report Share Posted December 2, 2008 yes: i have a dealer about 30 kms from my place in Denmark, it s 50 euro per kilo, but i won t be there before next may.. I gues you can get something in the states, and get it shipped to Canada.I would first try to do as i ve said before: applying many layers one by one, that will also help the diffusion of light.Consider how much your buttons will stick out of the panel and apply a first layer that thick or just a bit more, that will keep the look ok.Remember that cheap silicone gets yellowish with time but i bet you know already.And no no way to get that stuff dry without air.Simone Quote Link to comment Share on other sites More sharing options...
nebula Posted March 6, 2009 Author Report Share Posted March 6, 2009 Several months later, although pitted, the buttons still feel exactly the way I want them to. They are only slightly squishy, and the 5-button assembly feels very durable. If not for the curing issue, the GE Silicone II would be absolutely perfect. While reading over all of this I had an idea: I'm going to squirt some silicone back into the mold again tonight, but this time I will stick some coffee filter paper inside the mold, at the front of the buttons. If all goes according to plan, the silicone will not seep through the paper, yet it should allow for a little air to get through. In a few days or weeks the silicone will set, I will soak the newly molded piece in some water for a few minutes, and the wet paper will come off of the hardened silicone very easily. Quote Link to comment Share on other sites More sharing options...
Primate Posted June 20, 2009 Report Share Posted June 20, 2009 How is it going with the buttons? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.