Hjem 737 Cockpit project Cockpit related Overhead gauges and displays
Overhead gauges and displays Print E-mail
Written by Vidar Fagerjord   
Friday, 23 March 2012 00:08
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Overhead gauges and displays
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There are some steam gauges and numerical displays spread around the overhead panels. Here's how I implemented the gauges, the ELEC panel and the FLT ALT / LAND ALT displays.

 

 

I ordered all my gauges and the ELEC panel displays from Opencockpits.com. I had some OC electronic cards lying around, and decided to use them instead of spending more money. In addition, the OC stuff is a LOT cheaper than some of the competitors. The gauges was half the price of the gauges I would prefer if money wasn't an issue. They look great, and the mechanics are decent enough (though you get what you pay for - some modifications may be in order). And this was in the package I received (plus two USB servo cards as well):

I ordered the gauges in a set, but had to add the outflow valve gauge since it's not in the set. The gauges does not come with a front bezel since most overhead panels comes with bezels / faceplates anyway. The gauges looks very good, and are easily backlighted. Here's some detail images:

The image does not pay credit to the effect - they look very good!

The OC gauges does not fit my FlyEngravity overhead. Some modifications is necessary, and I'll get back to that.

ELEC and pressurization panel displays

I made a holder for the ELEC panel display from some plexi glass. Since my overhead require backlighting, the holder also has to prevent any light bleeding through.

I cut out the holes for the LED digit displays, glued some pieces to form a raised frame then painted the whole thing dull black. The holder is held in place by the DZUS replicas. which consist of a "DZUS cup" and a M4 bolt. The holder slides over three M4 bolts and is secured by nuts.

The mounting holes are shown along the left side of the plexi glass on the image above.

Here's the holder with the OC elec panel PCB in place:

From the back:

The PCB itself is secured by two screws. And this is how it looks when mounted in the overhead, behind a smoke grey window:

The window is glued to the back plate and stays in place if I remove the light plate. The panel looks very good, and once lit you won't be able to see the cutouts. The displays are just barely visible through the window when not powered. And yes, they are green when lit. :)

 


 

Pressurization panel displays

Similar to the ELEC panel display holder, I made a holder for the pressurization panel displays as well using the same approach. A small piece of plexi glass cut to shape, then I routed the cutouts with my Dremel and a straight router bit. I used the drill press stand for the Dremel for this. By drilling a pilot hole, I could lower the stand so that the router bit was at the desired depth. Then I just routed the holder free-hand. No need to be very accurate, except for the cutouts where the LED digits goes. Those cutouts I finalized by hand, ensuring a snug fit. I had to make a groove slightly larger than the cutouts in the overhead, since the grey window inlays are a bit thicker than the back panel.

As you can see, I painted the area around the displays black in order to prevent light bleeding. I had to stay clear of some areas so that the paint does not obstruct the cutouts for the panel backlighting.

Two thin pieces of plexi glass are glued to the holder. They was much easier to work with in order to fine-tune the openings for the LED digits - and they also created enough space so that the LED digits does not touch the window inlays. In the center of the holder, a square cutout was made for the encoder for adjusting the FLT ALT value.

Here's an angled shot of the holder:

This time I wanted to try another way of mounting the holder, so I used some 5 minute epoxy and glued it in place. Worked like a charm! I'm going to use this method for the gauges, as they need some sort of holder as well.

A sticky situation...

I used some liquid tape on the back of the PCB's and around their edges to block any light shining through. Apart from a small "leak" on the bottom of the FLT ALT window (which I am going to fix!), this worked beautifully!

Here's a snapshot with the light plate in place:

I am working on fitting the valve gauge, so this area will get more attention soon. All in all, the holders worked beautifully and gave me ideas for how to mount the gauges. I'll get back to that.

 

Update 02. April 2012
The idea I got from the display holders resulted in this approach:

I epoxied a small piece of plexi glass underneath the gauge to give it some support. The gauge itself will be held in place by screws going through the metal back plate and secured by nuts. Easy-peasy. If needed, I could also make a fastener between the gauge and the plexi glass piece - an approach I might use on other gauges.

The task at hand is to mount all the gauges, and I expect to be finished pretty soon. Some modification is needed on the Opencockpits gauges in order to make them fit. In the image above, you might notice a groove on the left side of the gear. I had to remove the white plastic in that area, and the black paint on the front, to allow light to pass through to the text on the light plate. Boy, do I wish I had the FDS overhead with IBL panels now!

I also cut a small piece of clear plexiglass and glued it into the gauge face-piece provided with the FlyEngravity overhead. And this is how it looks, mounted in place:

I am VERY happy with the result! I also used some liquid tape to stop any light bleeding on the FLT ALT / LAND ALT displays. Worked beautifully! Here's a few images of how it will look when backlighted:

You might notice some light bleeding between the panels at the bottom of the image, and that the annunciators light up. I'll fix that, probably with that liquid tape. Great stuff!

The fuel panel with the fuel temp gauge mounted. The backlighting is not uniform since I only used a desk lamp here. The cross feed knob is very dark, and that's something I'll have to look into. Perhaps a LED strategically placed. Time will show...

The air condition panel with the duct temp gauge in place. The darker area on the gauge is the shadow of the gear mounted on the servo. Careful placement of the backlighting should take care of that. I haven't mounted the gauge rings yet. I am looking into different ways to make the glass inserts, as I want glass on the front of my gauges.

I really like the Opencockpits gauges. Affordable and looks good. The servos seems to be rather cheap, but as long as they work...

So far, I am very happy with this. The overhead panel is close to completion at this time. After I'm done with the gauges, I'll start work on the backlighting.

Updates to follow soon (enough).

 


 

Gauges mounted!

Finally, all the gauges are mounted in the forward overhead. All gauge rings with lenses has been mounted as well, apart from fuel and duct temp. Those will get some special attention to detail soon. I had to fabricate lenses for the gauge rings in order to get "glass" in front of them. Tedious job! I made a sheet of paper into a big sticker (using a scrapbook laminating machine of all things!), then I used a compass to draw the 6 lenses on the paper. The big one for the diff press gauge came from a Simkits instrument kit I had "lying around". :)

After I made a big sticker with 6 rings on it, I applied it to a 2mm acrylic glass sheet. I then cut out each ring and sanded it to shape. I fine-tuned the fit to the rings with a file and some 180 grit sand paper, leaving the edges "frosted". I then glued the lenses into the rings with some plastic model glue, leaving .5mm of the lens protruding to create a nice, 3D effect - and in the same time leave extra space between the lens and the gauge pointers.

 

Here's the 6 gauge rings with lenses fitted. The 7th lens is for the oxy press gauge in the aft overhead.

The cabin diff press gauge ring and lens, showing the protruding lens.

 

And here's a few pictures of the gauges WITH rings and lenses fitted:

The EGT gauge for the APU.

The cabin diff press gauge and the cabin climb gauge. Nice reflection on the cabin climb gauge!

 

You might notice that the cabin diff press gauge looks different from the Opencockpit one. The outer ring was too wide for my FlyEngravity overhead - the numbers was partly hidden behind the back plate. I cut a piece of plexi glass to shape (and gained access to the four screws in the same time, as the OC gauge is too narrow for the FlyEngravity OH), routed a hole in the middle and painted the edges of the hole black. I then used the decal included with my overhead kit, and cut away the center portion. For that, I used the OC gauge as provided. And I am VERY happy with the result! The yellow / red colored part adds to realism. I might get hold of some blue transparent paint for the cabin climb gauge. Just because I can, and because I am a detail freak - to a certain degree, that is.

PS: I used the same method for creating the new faceplate as I did for the lenses. Made a sticker, applied to the acrylic piece, drew the diagonals between the holes to find the center. Using the compass, I then drew the required circles to aid the cutting of the hole. I used the Dremel with a straight router bit, all mounted in the drill press stand for the Dremel. Messy, but very accurate and effective.

The duct press gauge backlit by my desktop lamp. Not the best effect on the outer ring since the gauge consist of 2 white, opaque pieces. Acceptable, though!

 

The last two gauge rings will, as mentioned earlier, get some extra attention to detail. More on that later.

Update 08.04.12

The final gauges on the FWD overhead are now mounted and ready for use. The cabin temp and fuel temp gauges needed a little extra detailing. I cut out a detail from the decals provided with the overhead kit and mounted it on the gauges, then mounted the lens. Here's the result:

The fuel temp gauge

The cabin temp gauge

The lenses give a very nice effect with the reflection in the glass. Looks very real!

And here's an image of the overhead with almost all the gauges shown:

That concludes the gauge part for the overhead. I'll post an image of the oxy press gauge in the aft overhead when that one is mounted.

The next part will be to configure the gauges and the displays on the overhead using Opencockpits cards and SIOC software. I've also considered ordering simkits electronics cards for the gauges, as they are somewhat easier to work with. Haven't decided on that yet.

All in all, I am very happy with the Opencockpits gauges. The quality is decent, and you get a lot for your money. The Flight Illusion gauges would be far better, but they costs about twice what the OC gauges costs.

The dual opaque layering on some of the gauges causes the outermost lettering to be a lot dimmer than the innermost. This could be solved by cutting the innermost piece around the gauge face and replace the area around it with clear plexi glass. Another option would be to follow the solution I came up with for the cabin diff.pressure gauge: making a new faceplate (clear) for the outermost piece and use a sticker for the gauge face. The backlighting on my diff.press. gauge is very even because of this.

The OC gauges comes with "okay" servos. One of the gauges is acting up, and I think the servo might be defective or damaged. I'll consider swapping it, or leave the oxy press gauge as a dummy (swapping the servos from the oxy press to the defective one).

 

 

Last Updated on Sunday, 08 April 2012 16:58
 
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