Boeing MCP/Radio LCD display size????

[phil744]

Hello,

Two things really..

1, as this is my first post of many I hope i would like to take this oppotunity to say hi.

2, On the 777 MCP and XPDR/Radio stack you see those nice looking supertwist LCD displays, Does anyone here know exactly what size the digits are?, I am currently making bespoke white displays with status indicators for my setup with excellent result's so far and I just want to clarify that i have all the dimentions correct?

any help would be greatfully appriciated.

[Trevor Hale]

Welcome to the forums. I am sure there is someone here that could help you with this. I just want to say Hi, and welcome you to Mycockpit.org I hope you are ale to contribute your experiences to others in the community.

Best regards,

Trev

[Michael Carter]

Hi! Welcome to the site.

If the 777 radios are a standard 5-3/4" wide as they are in most Boeings with radio heads made by Collins and Gables, you might be able to extrapolate the size of the digits for your bespoke radios.

On the Collins analog dials the numerals are 8.5mm or 11/32" in height.

[phil744]

Cheers Guys,

Its annoying, i have half a 767 pedistal sat here and the only panels missing are the nav radios/transponder and i dont have anything with a display on it,

Just bought a 737 radio fascia from engravity and i will try as you say and work out the size of display from the window cutout, i figure its around 10.77mm and made a simple dual segment display, however it still seems a little big, im sure someone around here may have one to hand and put me out of my misery by letting me know what the official size is.

Anyway here is a pic of last night activitys, its far from finished, and i mean far, but got the pcb etching down to a fine art and soldering 0603 smt LED's (AKA dust!) with a chizel bit sorted, just need to make a few more and try injecting the resin, the picture shows just the trial body without resin so there is a lot of light bleedthrough.

anyway, onwards and upwards.

http://i17.photobucket.com/albums/b52/madmini1/DSCF1741.jpg

[phil744]

Right, a little more progress made, ive injected the resin, built a few more PCb's and finally got 1 prototype working, the original light bleed through has almost dissapeared, there is still a lot of glowing coming from the rear through the PC board however once i get round to making the full housing that problem will be cured once and for all.

here is the 1st protype for testing

http://i17.photobucket.com/albums/b52/madmini1/DSCF1742.jpg

before anyone states the obvious that i have forgot to include the decimal point i have omitted this for now, the pcb design is complicated enough, and i will only be putting in decimal point as and where there needed, no point in having redundant LED's in there, there expensive enough.

http://i17.photobucket.com/albums/b52/madmini1/DSCF1753.jpg

And here it is illuminated, there is no reason why its saying 64, i just wanted to see two different number instead of just "88". unfortuantly the material ive used to construct the body has some air pockets in there that make's the edges look a little rough but this is my first prototype, not bad i say, still think the artwork needs some tweaks though. And these little buggers are bright:cool:, which is good because i can add more diffuser to the resin to even the light distribution, not bad when considering the thickness of these is approx 4.5mm.

Work is sending me to China on Thursday for 10 days so i will illuminate all segments and leave it running to see how it behaves, and hopefully go LED shopping whilst in China:p.

Please feel free to comment or add suggestions.

By the way, i still need the size of the real parts ;)

[Michael Carter]

Wish I could help with the actual digit size, but the display looks great.

Someone with a digtal radio stack should be posting for you soon.

[DAL900]

I don't know if this will help, but look on my page and scroll to the bottom. I sold my radios a few months ago so I cant open them up


http://www.projectb737ng.com/737ng_reference_photos.htm

[phil744]

Hi Guys,

Many thanks to David who emaile me a drawing, i now have the answer i was looking for, if you are curious it is 8mm, so they appear to be a little less than the old analoug ones, i thought they would be bigger, so now i have to serously re-design the layout for this reduction in height.

my part has arrived from engaravity however i am 6000 miles away in china so i will continue once i return, i visited an led factory today who would be quite happy to produce a custom die bonded PCB so i am just awaiting the cost to see if it is feasable.

DAL900, many thanks for you link, that has really helped to clarify the overall dimensions of the radio stack, when i get time i will collate all the info i have and upload them here

Many thanks for your help guys, i will keep you poster once i return home.

[phil744]

You ever get the feeling that you have bitten off more than you can chew? I know I do.

Anyway, im back from my grand tour of China and its time to continue with these little displays. Now i know the measurments i now know its nearly impossible to reduce them to the correct size of 8mm, however at 9mm I can just about do it. So after the grand re-design last night i managed to get 1 dodgy looking prototype up and running, and here it is:)

http://i17.photobucket.com/albums/b52/madmini1/disp6.jpg

As you can tell its a very, very long way off being called finished, but it's progression and in the right direction, i ordered some glass with the same anti reflection coating as used on the real part, coated and etched to produce the mask for the actual segments but i cocked somthing up because they dont quite line up with each other yet. however when placed in a nav radio panel it is starting to look good


And i also realise that i cant cut glass to save my life, i can post a pic of the gash in my hand if you like, i was told to expect blood sweat and tears when constructing a flightdeck, and they where right.

[phil744]

A little closer :)



http://i17.photobucket.com/albums/b52/madmini1/DSCF2690.jpg

[phil744]

Many thanks to David for the 737MCP display drawings, they are becoming very useful whilst attempting the impossibel:)

A little update on the madness

I moved over to prototyping the transponder display because its larger and requires less LED to complete, at the moment I have around 9 7X6 displays on the scrap heap and when you imagine that being 392 scrapped white LED’s it’s starting to become quite expensive. However I have hit a brick wall at the moment with these displays ,I can’t yet master the art of injecting the resin into the individual segments, I did use medical syringes with needles but the resin is more like a syrup so nearly impossible to do, not to mention my work area looks like home to the local crack addict because of syringes lying around!!!! I am now dispensing resin to the individual segments under perfect vacuum conditions that does actually work but it is such a pain in the arse.

However I have found that applying a white silk screen mask on the rear of the glass produces perfect results without the need to inject this disgusting resin stuff, only problem is that you can see the “off” segments which is not good, they should be nearly invisible when off so either I get some tinted and coated glass or use a thin piece of tinted Perspex to apply this mask to, then sandwich between the LED body and top glass, this is what I’m working on now.

The second problem is the main LED housing, If I use black plastic to produce this it works well with zero light bleed through, however I don’t get a uniform light surface across the segment, it appears dark and patchy, If I produce the housing in white the light across the segment is amazingly bright and perfect, however because of this bleed through in the rest of the segments also light up, which is not good. However I do have an ace up my sleeve to solve this, keep in mind the wall section thickness at the tip of the taper between segments is 0.2mm or 0.008”.

Here is a pic of the transponder revision 1 display, looks crap I know but we have to start somewhereJ

http://i17.photobucket.com/albums/b52/madmini1/xpndr-display.jpg

If you’re interested, I did one mask that instead of having the usual 7 segment style I replaced the individual segments with 3 pixels to replicate the old style indacesent 7 segment displays you see on old 727, 737 and in the engine standby gauge and IRS panel used on the 757/767 and they looked beautiful, if I find my memory card I will stick a picture of those up, I’m quite proud of those.

[Michael Carter]

That's really fine work you've done wth your bespoke radio heads.

Looking really great!

[dnoize]

amazing piece of work i have to say.

This brings simbuilding to a higher level.

Good work !

Stef

[phil744]

I bet you all think I'm Mad? I say it helps. Ok, After a little more of a productive weekend I am pleased to announce that I may of "cracked it" :)

Basically I am cutting the Black mask, adding a clear coat then a tint film across the rear, basically it is the same stuff you would use if you where going to tint the windows on your car, then apply a white filter mask which means thast I dont have to inject a diffused resin into each induvidual segment which belive me is a nightmare to do.

Unfortuantly they are not a bright as I wanted, however the LED housing is still made of Grey plastic that removed a lot of the light, I tried with a white body and apart form the bleed through they look bloody amazing with clarity that I could only dream off. but you now doo well to spot the off segments, however this will improve once I get the correct perspex Tint sorted.

Anyway, enough of talking about it, here is the proof!!

http://i17.photobucket.com/albums/b52/madmini1/DSCF2793.jpg

And I had another go at the "Dot Matrix" version aswell which I am ver very happy with :)

http://i17.photobucket.com/albums/b52/madmini1/DSCF2789.jpg

Even down to the actual segment looking like induvidual bulbs as on the real part, by the way, this was not planned it just happened, well impressed:)

http://i17.photobucket.com/albums/b52/madmini1/dscf2442.jpg


Ok, I require your help again, I have been asked to look into trying to build an Airbus A320 FCU/Autopilot Display, and the BARO displays, Has any one got a decent drawing/ Hi res photos of this part and the panel cut out size to hand so I may give these a whirl?

( yes I am Mad)

[phil744]

After a slightly longer stint abroad im back and now its time to continue with the madness. unfortuantly for me the deal i had for my own small unit for the sim has fallen through so I am still looking for a place before i can even consider starting to build my sim.:(

First off it was time to re design (yet again) the PCB, this time there double sided and multiplexed common cathode or common anode depending on what interface i decide to use if i ever get round to choosing one. On the first revision of the PCB i managed to cock somthing up where only 1 row would illuminate and everything else was shorted out, however on the second attempt I got it right:p and here is the naked PCB...
http://i17.photobucket.com/albums/b52/madmini1/DSCF3142.jpg
http://i17.photobucket.com/albums/b52/madmini1/DSCF3135.jpg

Now I have that working i can finally get around to producing some form of encapsulated enclosure for them, initially i decided on 4 screw lugs and a body that will fit directly into the machined panel fascia but looking at the panels i have i realised that if I was to make the body 2mm bigger in both heigh and with than the panel cut out they would fit perfectly and produce a nice neat snug fit and 2 screw lugs would be enough to fix them, bring on revision 2 of the housing!!. However with this being the first run of 2 pieces yet again i managed to cock somthing up, i think i got the mix and cure time wrong because when i releced them from there mould the plastic had not yet cured fully and was still tacky and started to warp, thus why the look crap, but i know how to fix this (i hope)

http://i17.photobucket.com/albums/b52/madmini1/DSCF3144.jpg

And i simply screw them either into the metal back plate of the plexi fascia itself.
http://i17.photobucket.com/albums/b52/madmini1/DSCF3143.jpg

But overall I am very happy with what ive achieved so far, I just hope soon I wall be able to crack this once and for all!!

http://i17.photobucket.com/albums/b52/madmini1/DSCF3141.jpg

[AndyT]

Beautiful work my friend. Keep us posted. Would you share with us the kinds of materials you used in this project so far?