Boeing MCP/Radio LCD display size????

[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



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!!



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



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




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 and here is the naked PCB...



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)



And i simply screw them either into the metal back plate of the plexi fascia itself.


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!!

[AndyT]

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