DIY illuminated buton, Datawheel for the MIDIbox Community

[DrBunsen]

While Googling for suppliers of RTV silicone in Australia I found lots of hints online in model-making and cinema prop making circles.  Seems like others have found Dow Corning silicone sealant ideal for their purposes.  I'm thinking of making a mould for an 8x32 button array out of that or the RTV silicone.

[Mr modnaR]

My question was actually on how to get the stuff thinned out enough (while wet) that it could be poured into such an intricate small shape. What do you cut it with to keep from ruining it?

i'm making a solid mold, so i'll (hopefully) be able to inject it.

by mix the 'white and clear' do you mean there's a white version of the sealer, or is there some powder that makes the clear more opaque?

[Jidis]

do you mean there's a white version of the sealer

Yes, at least that. I think there's even weird stuff like bronze colored. This is just the regular construction adhesive silicone I'm referring to (the kind that comes in a caulking gun tube). Moxi's got access to some sort of powder. I'm on a more low tech-angle. ;D  (I need to figure out where they sell all the real stuff like that here)

George

... a "guru" huh?

I figured I was about to turn into something. Don't feel like much of a guru though. :-[

[Mr modnaR]

where are you based? if UK, Tiranti's are a good source of moulding and casting supplies

[Jidis]

Hey again,

No, I'm actually in the US. We probably have places that sell stuff like that in town, I've just been too lazy to look. Being awake until 7am doesn't make it very convenient to do "day stuff" here either. ;)

I've got some people I can ask here too. Finding out what most of the stuff is actually used for would be a good start.

Take Care,

George

PS- Main reason is I haven't really needed to mold things lately. Once I get back on that part of the stuff, I'll probably go back to looking around.

[Dolphinicus]

I had a new angle of thought on the way out for supper this evening. :)

What about completely clear silicone?  It maintains a fair rubberyness, no?  If there's not much of it above the panel, with no 'sharp' edges, it should last for a fair while, no?

I'm quite curious about this, as I came up with a completely new 'labelling idea' for each button, on the way out to supper. :)  If others think that the clear silicone will work well for the actual 'button' containing the LED, I'll give it a shot and see how well it works. :)

[Jidis]

I think that's the same stuff we're referring to, but it was mentioned here previously that the hazy white stuff distributes the light a bit more evenly (I think that was how Moxi ended up with that shade for the resin).

I was thinking of sticking things into the lower portion of the buttons as well (actually with resin, but clear like what you're talking about on the silicone). Seems like if you cut pieces of transparency with your desired prints on it, and maybe painted or poured a thin layer of your button material into the mold first, then laid those in and poured the rest on top, you'd get a label encased in resin (or whatever). Hope you try something like that so we can see how it does. I'm stuck in the middle of the construction of the world's worst MB core board right now (valley of the vias) and haven't been doing much else. :-X

BTW- I was also considering that some sort of toner printed material laid into the bottoms of the molds might stick to the button material while it dried, having it's carrier sheet be removable afterward by soaking etc. There's an aluminum foil I tried here for toner transfers, per someone's recommendation, which doesn't get a good grip on the toner. It's just sort of sitting on the foil, and is easy to smear off. I was wondering if something like silicone or liquid latex dried while sitting on top of that, if it would "glue" the print into the material, sort of like rubber buttons with silkscreening.

Please let me and everyone else see if you get anything good happening with the labels :).

George

PS- There's also the alternative of "rubber coated" stuff, which feels about the same, depending on how much you layer. There's a piezo encased in FG resin, near the beginning of this thread, that I painted with liquid latex for mold making. Tapping on it with fingernails feels about the same as one of the harder MPC style pads (I didn't put all that much on it). 

[Dolphinicus]

Printing of the labels, aye. :)

The full idea to try today, as I'd decided on yesterday for the LED'd button - described from the top to the bottom of the button by layer:

- clear silicone

- printed label (within button's diameter) - black lettering on white paper

- LED contained within more clear silicone, legs pointed out the bottom

My standard panel thickness in my 19" modular's rack, is 5/16" (currently using Maple).  I would like have to the tops of the buttons sticking only a few millimeters (between 1/16" and 1/8") above the surface and rounded.  I'm roughly figuring that the entire silicone portion of the button's length will be 6/16" (3/8") to 7/16".

The legs out the bottom of it will be bent at a 90º angle, where the button will be seated just above the tact switch, and then a slight angle down to the soldering points on the board.  This should provide a decent spring action for the button, as well as the spring action of the tact switch, to keep the button elevated.

I'm hoping to angle the legs in such a way, that there'll be as little strain as possible at the solder joints.

Mounting the buttons this way also, should free up any need for securing them to the front panel. :)

If all goes well, I'll have some Plaster of Paris for making the molds as well as clear silicone, this afternoon.  Shall be photoing the event as it goes to see how it all comes about. :)

[DrBunsen]

BTW I've just come into a large supply of LEDs with right angle legs.  Should be arriving in a week or so.

[Dolphinicus]

And I just came into a supply of 1,000 9mm tact switches. :D Should be arriving in 1 to 2 weeks. :)  Wonder how many MIDIbox SEQs I could build with that?  :o  LOL

Right Angle LED mounts would be excellent.  With my preference for different colours (using no Red LEDs at all) though, I may be limited to colour choices I could get. :(

I was just looking at my LED supplier ( www.lsdiodes.com ) for dual colours and it's only 3mm red/blue, blue/green or red/white.  :-\  I was hoping for blue/yellow.  Oh well.  Single colour LEDs it may have to be.  (Local supplier yesterday only had red/green, in all of their duals, as well.)

[Dolphinicus]

Well - over a 6 hour period yesterday, I got my first 5 LEDs in silicone done.  They're currently curing and I hope to be able to extract all of them after work, tonight.  :)

I've also been photographing the entire procedure from the very start.  I'll more'n likely be posting the pics of the entire event at a section in my webpage, to not tie up the transmission time to viewers of this thread. :)

Some bits of possible useful info. so far:

- In a brief (roughly 2 hours) test of the silicone sitting on top of some 'dry PoP', it removed easily. :)  I'm hoping that the same will hold true, once both the silicone and PoP are properly cured. :o :)  Otherwise, I'll have to break apart the PoP mould, to free the silicone'd LEDs. :o

- the softer wood, wooden spoons that I bought to put into the Plaster of Paris, do NOT adhere to the PoP; they remove fairly easily, after the PoP has been curing, for just over 1 hour.  (The PoP is almost rock solid, though still feeling damp.  Requires a 24 hour curing time.)

- CORK however, CAN be extremely difficult to remove, due to it's breaking apart easily. :(  I wanted to do a larger test button for my 'Play Stop Pause Forward Reverse' buttons and used a pair wine bottle corks (1 on top of the other, for a 1 1/4" depth).

The top one removed quite easily.  The other one below it, inside of the PoP though, wouldn't come out.  It had to be broken apart inside the hole in the PoP to get all of it out.

This made me possibly realize another trouble.  Due to the extra thickness of the siliicone in the cork hole, it may itself require longer than the standard '24 hour' curing period for silicone, that is used for sealing spaces along your house's window installation. :(  I'll find out after work tonight, when I try to remove the first of the 5 LEDs in silicone, from the PoP. :)

- I made the entire wooden LED mould master, 1" long.  This gives me enough length to have approximately 1/8" of the rounded tip, sticking above the panel for pressing.  There's enough of a length after the 5mm LED body, to trim the unneeded silicone away, when I come to finally mounting to the silicone'd LED, over the tact switch.

- I have NO idea what the printed and handwritten paper labels inside of the silicone will look like yet.  Shall hopefully find out tonight.  I'll be taking pictures of it all regardlessly, to put into the set of pictures of the entire construction.

- Another thought that I had:  I hope that finger / skin oils, don't muck up the clarity of the clear silicone, when in use.  If it does, that'll basically kill the silicone idea.  Shall find out over time.  :o  I'd MUCH rather have 'soft feeling' buttons though. :D

- My girlfriend pointed out one possible advantage, to the 8 ounce margerine container, full of PoP, that had dried too fast for me to be able to put the pieces of wood into:  once the shape is cured, I can just DRILL new holes into it, for putting new LEDs and silicone inTO! :D  The very tip of it wont be properly curved, the way the wood from the wooden spoons is, but once I remove the silicone'd LED from it, I could cut the tip to the curvature that I like and all will be swell! :)

That's all of the info. for the moment.  Hopefully - the silicone'd LEDs will remove from the PoP tonight, and I'll be able to use the PoP mould for more buttons! :D

I'll type more on the development tonight, after work. :)

[Dolphinicus]

Ya know?  When you accidentally touch both ends of an Ultra Violet LED in a silicone 'button', to the fresh bran spankin' new 9V battery, it very quickly (1/20th to 1/5th roughly, of a second) glows bright green, which just as quickly switches to a bright yellow (what happened to the Violet?  Didn't see that at all. :P ) before releasing the magic smoke, through the silicone. :o :(  :-X  :'(

And that was on the only fat one, that I'd done. :(  (With the cork).

3 of the other 4, are the Sea Green shade, which through the clear (cough cough, right) silicone looks LOVELY. :D

The LABELs however, do NOT work at all. :(

You're clearly able to see blockage of the light, which takes away from any attractiveness of the button itself.  Without the label of paper inside, it'll look FAR, FAR better. :o :)

The imagine quality / colouring aren't the greatest.  I'll have to try photoing the next LEDs against better backgrounds or in complete darkness or something.

3 of them had been done with Sea Green LEDs inside; the 4th, with a Yellow and the fat one with the Violet.

The button FEELs great from the top though!  This is definately going to be, how I make my buttons. :)

[Mr modnaR]

are they not too soft? what is the Shore A hardness of the silicon you are using?

thanks

[Dolphinicus]

Actually, no - it's a fair bit harder than I HAD expected it to be.  But it IS a very nice firmness with just the slightest bit of give, which feels very comfortable when pressing down on it.

It's not so much give, that you'd have to press harder, to activate the tact switch.  No problem there. :)

I'll check the data on the box in the morning and post it.  If it's not there, I'll head to the Lepage website and search for a data sheet on it. :)

[Mr modnaR]

thank you, much appreciated!

[Dolphinicus]

Shore A Hardness. :(

Sorry.  There's nothing listed on the package of Silicone at all; the online site for the company from which I bought it (Mastercraft Product from Canadian Tire) doesn't even recognize it's own product, by it's product name or identification part number. :(  The only other info. as to id'ing it - were that it's been manufactured in the U.S.  No company ID or anything.  (Was hoping so - to see if I could find it's MSDS / WHMIS sheets.)  The best that I can do - is type the product info. from the package. ??

Edit:  All of the pics through the manufacture of the test buttons, are now up inside of this section in my webpage:  http://www.sdiy.org/damian/EBG/ebg.html

[Mr modnaR]

that's cool, thanks for trying. the buttons look really good, post some pics when it's all done! ta

[Dolphinicus]

Thankee muchlee, Mr. Modnar! :D  A posting I shall do.  I'll try as I might, to get the best lighting setup for my digital's pics as well as video, to show the button's light, as accurately as possible.

Next time that I'm at Canadian Tire, I'll ask them for MSDS and possibly WHMIS sheets of this silicone product.  Hopefully, that may have the datum that you're after. :)  Me - being a newbie in these regards, am just happy with the feel / functionality of the button, at this size. :D

Realization as to the cloudyness / non-clearness of the 'clear silicone' will be due to it's being seated within the plaster itself, causing micro and larger 'holes' in the silicone, which will be giving it that 'cloudy' effect, which works quite well to hide the LED inside of the switch area itself, as well as disperse the light in all directions. :)

[AndrewMartens]

Next time that I'm at Canadian Tire, I'll ask them for MSDS and possibly WHMIS sheets of this silicone product.

... and you'll be met with blank stares and confusion  ;D

[Dolphinicus]

... and you'll be met with blank stares and confusion  ;D

MOST definately! :o  I'll steer towards an older person though, figuring the chances are greater for success within those regards. ;)  :D

[Mr modnaR]

thanks, i was just wondering if the buttons would be too soft without the leds. i'm going to be doing some illuminated buttons with the leds mounted behind, on the pcb, but i'm not sure if, with your buttons, the leds are providing a lot of support?

[Dolphinicus]

thanks, i was just wondering if the buttons would be too soft without the leds. i'm going to be doing some illuminated buttons with the leds mounted behind, on the pcb, but i'm not sure if, with your buttons, the leds are providing a lot of support?

I just tested the cork (dead) button, as well as the top and the bottom of the normal buttons (all with 5mm LEDs inside).

I have a fair amount of extra silicone below the LEDs in all of them, so that I could trim off any excess that I don't need, when I'm mounting them above the tact switches.  The stiffness of the silicone above the LED (about 1/8" to 1/4" thick) has roughly the same tension, as the 1/4" to 1/2" below the LED.  A very nice stiffness.

I had also tested the silicone (about 12 hours cured) around a circle of LEDs in a lighting design of mine, and it's still very soft.  In another 12 hours at least, it'll be as solid as that around the LED buttons.

Dimensions of the silicone of MY buttons, for hopefully extra clarifcation is:

Length: 1"

Width: 13/32" (just the slightest hair under 7/16")

(cork)

Length: 1 1/8"

Width: 3/4"

I hope that helps somewhat. :)  For 85ml, the tube of clear silicone was only $2.99, at least.  So it's not an expensive test, at least. :)

[Mr modnaR]

that's great info, thanks. looks like i'll be ok with my buttons, hell, if worst comes to worst, i'll just have to stick leds in the buttons!

[Dolphinicus]

The technique that I used for placing the LED into the hole with the silicone were:

(Presuming the hole in the Plaster of Paris is properly ready - dry for 90 minutes, seemed okay to me.)

- I squeezed in between 1/8" and 3/16" of the silicone (on to which I placed a label).

- I then dropped the LED in, resting my fingers on the top of the plaster, grabbing the LED legs with my figures, so that I knew exactly how deep the LED were in the socket.

- While holding onto the LED, removing it from the socket, I filled the hole about 2/3 full with silicone.

- I then moved the LED down into the hole until my fingers JUST barely touch the edge of the plaster.  (To keep the LED at the height / position that were determined earlier.)

- Finally, I centered the LED legs standing straight up and filled the rest of the hole, just slightly over the edge.  How much ever silicone is not needed later, can be trimmed off. :)

I far prefer this idea, to mounting the LED separate from the silicone itself, as the LED's legs will operate as the spring for the switch itself. :D

[Mr modnaR]

I far prefer this idea, to mounting the LED separate from the silicone itself, as the LED's legs will operate as the spring for the switch itself. :D

i'd be careful with that, because LED legs are not meant to be moved about once mounted! you may find that they break off in a fairly short time. just warning you!  8)