Homemade switch for 744 MCP

[Guest mbessler]

Its been a while since I updated my cockpit building pages......but yesterday I uploaded quite a bit of new stuff, for example my tests of how to make cheap MCP switches for my 747-400 MCP. I believe that the switches used on the real thing are from Korry.The Korry 389 Series seems to me the right one. Here's a link to the datasheet which has all the dimensions:http://www.korry.com/PDF/Korry_389.pdfAnyway, heres a picture of the switch I made. Its still missing the actual pushbutton.http://forums.avsim.net/user_files/45895.jpgMy homecockpit building homepage:http://cockpit.varxec.deMCP Switch gallery:http://cockpit.varxec.de/panels/switches.htmlPS: I'm trying to collect infos on stuff like the switches used in cockpits, along with links to manufacturer pages, datasheets,...I've already collected a few parts like the Korry switches and knobs stuff and some more. I'd be nice to have a page (in the future) with cockpit pictures of several (mostly) airliners with clickable areas for those parts where you get a page describing who makes it, maybe dimensions (where the datasheets don't have them),...Right now, I have it all in a plain text file, not much organized yet... eventually I want to put this up on my site.If you have infos you'd like to share, post here or email me.PPS: The AML22 switches that many builders use... Are they actually used in real cockpits ??? I haven't seen them yet on airliners.net and similar...

[Garys]

The AML non illuminated ones are used on the 767. Its on the panel situated behind the F/O and is used to switch messages on the Eicas screen. Depending on type of aircraft illuminated ones can be found on the flight attendant controls at the doors of the aircraft.The AML 22 with the LED that is commonly used wont be found on any airliner cockpit that I can think of, but are great for our needs.Nice looking switch. Will it illuminate?Gaz

[Guest Ramsberg]

Nice work!!!I will steal this idea completely! Its much better than mine, which was almost the same, but the glue molding. I planned to use two pieces of 8 mm clear plastic with a black piece of paper between as a light blocker. then i would drill holes from behind for the LEDs.Realized that making the button part to fit exactly was very hard to do without the proper tools.Your molding idea is excellent!Question:Hot glue? what is that? Where to buy? brand? Never seen it beforeCheers!/ Olle

[jmig]

Impressive site. You should be proud.John

[Guest petrsn]

Excellent work Manuel !!!Your photo gallery presentation functions as a very good "how to" guide. I do have a few questions and will refer to the photo # within that galleryin most cases.Ref photo #32 : Does the semi-translucent qualities of the hot glue diminish the brilliance of the led's in any negative fashion ? I know they are near the surface and the haze effect of the glue probably acts as a diffuser.Ref photo #35 : Is there any special attention or method to ensure that the junction of the front and rear glue blocks make a solid connection to the led mount board ?Ref photo #36 : Is the cable connector sealed /encased in the hot glue ? Ref photo #43 : How do you plan on fastening the switch assembly to your MCP panel ?I am having difficulty understanding how and where the switch itself is implemented mechanically. The glue block you created contains the led's only, correct?Thankyou and all the other pit builders for sharing your knowledge. They are as inspirational as they areinformative.Thanks again,Tom Peterson

[tigert]

>Question:>Hot glue? what is that? Where to buy? brand? Never seen it>beforeAsk your hardware store for "hot glue gun" -those exist everywhere and they are cheap.Something like this:http://www.cir.com/tools/608-363a.gifSizes and looks differ, there are several ones. Just get enough of those glue sticks as well :)Basically the "gun" melts the glue and it becomes clear and fluidy, then when you apply it it cools down and becomes stiff again. It stays somewhat rubbery though so it makes a flexible joint. Very useful for building other things too than just filling up the buttons. Although it becomes somewhat white again when it cools down, I bet it lets light through enough, and it probably acts as a nice diffuser anyway.Just watch out, the glue is *very* hot and sticks to your skin if you get it on your hand etc accidentally, so really beware.Tuomas

[Garys]

Another simply way of making an illuminated switch is to take an AML switch, Drill a hole in the back large enough to fit a 3mm LED. Takes all of about 2mins. Then all thats left to do is make your legend. For the AML Series 22 which has the built in LED just gently pull its Housing off from the front.Its better to use ones without a resistor as it gives you more room inside the switch. The only drawback is that room is tight so you will only be able to fit 1 LED in their so you cant have both Legend and bar lighted seperatlely but with AML switches available for $6 its as cheap as chips, has a nice strong tactile feel and you dont have the mounting problems. Gaz

[Guest mbessler]

@GazYes, it will illuminate. Just haven't hooked up the wires yet.I'll have to look for pictures of the AMLs on 767s on airliners.net. Thanks for the tip.@OlleTuomas' "a picture is worth more than a thousand words" answer made it clear... maybe I should have written "glue gun" instead of hot glue.For the glue sticks I use: They are the cheapest kind I got. A bag of 20 sticks, 20cm long, 1.12 cm diameter cost me 4EUR. Its the clear kind. Some of the special kind of glue sticks are often less or not at all translucent at all.Here's a picture: http://forums.avsim.net/user_files/45958.jpg I've had a couple of ideas before this "hot glue" one, but they all had something I didn't like. The hot glue idea came when I wasshopping for cockpit stuff at a local home improvement store.The good thing about this is, that the things you can model are only limited by the molds you can get/think of. Like the AP disengage bar I also made with the same technique. I'm already looking for something that'll make a good mold for the vertical speed thumb wheel :-)Be sure to post pics of your results and report about improvements so we all can learn :-) @John Thanks for your compliments.It also is a lot of work. Even with lots of "automation" I'm using. This last webpage update took more than 5 hours (after dropping all pictures in a directory, ready for commenting)@TomThanks.photo #32: since the legend LEDs are further away from the front, the diffusing effect is stronger, which is a nice property for the legend. The rectangular LEDs are pretty much at the front surface, thereby having a much weaker diffusing effect which, in this case, is wanted. That was my reasoning behind the different distances of the LEDs from the front surface. The only thing that I'd like to change is white LEDs instead of yellow ones for those behind the legend. Maybe the way the caps are made could be optimized,eg. so that the "bar" is only visible when the LEDs are on.photo #35: no. I guess the tiny holes of the board and the wires and LEDs hold it firm together. I think even the hot glue itself would stick well enough to a blank board.photo #36: yes its sealed into the glue. Maybe I should have wrapped part of the wire in paper. I should note that it is importanthow you set up the wires within the glue block since there must be a way/and space for the wires to move when you push the button.Thats why I don't have the actual microswitch/pushbutton installed yet.photo #43: I'll probably either use hot glue or some mounting brackets (aluminum). The third option would be to solder pinheads (those jumper blocks/ harddrive connectors) to the board holding the pushbutton and then have a "back plane" where you stick all switches into using those:http://forums.avsim.net/user_files/45960.jpgAnd yes, the glue block only contains the LEDs.Regards,Manuel

[tigert]

>Ref photo #32 : Does the semi-translucent qualities of the hot>glue diminish the brilliance of the led's in any negative>fashion ? I know they are near the surface and the haze effect>of the glue probably acts as a diffuser.Most likely you *want* to dim the leds - remember that when flying at night, you want to keep the cockpit lighting *down* so that you can see outside. And it takes about half a hour to get your eyes adjusted to low light. Very bright leds just distract you.Tuomas

[Guest Dodiano]

Dude where you got the metal housing for the switch itself?? I

[Guest Dodiano]

Dude where you got the metal housing for the switch itself?? I

[Guest mbessler]

>Dude where you got the metal housing for the switch itself??>I

[tigert]

>>P.S. Actually the AML 22 Pushbuttons are used in General>>Aviation Aircraft if I

[Guest mbessler]

>>>P.S. Actually the AML 22 Pushbuttons are used in General>>>Aviation Aircraft if I

[Garys]

AMLs are certified as you can see here on the 767 panel I mentioned earlier. However the reason you wont see the 22 with the built in led is because any indicator switch needs to be illuminated and they arent.Gaz