Instrumentation using rear projection

[Duckling]

I post this in a separete thread to not clutter another thread where this topic popped up. Had a short discussion about using this type of setup for the A-10 RWR and likewise and like to share our approach.

 

Very interested to see what other type of approches and the results been made.

 

Here is one example of using rear projection with a micro projector for instruments where a TFT/LCD is impossible to fit.

 

In this case its a A2A radarscope for a Swedish J35-Draken. The task is still WIP but the main build is ready and we use this in a X-plane based full size cockpit. Same approach should be possible with a viewport export from DCS such as RWR. Adding a green filter would be even better (I hope :- ) and a bit darker also.

 

This micro USB projector is kinda weak on light, have a long throw (low angle) and low resolution VGA.

 

We removed the tube itself and placed the projector with a custom 3D printed fixature where the 'neck' of the tube had been. Estimate distance from lense to lense about 300-400 mm so it was with a slight margin it fit with the required size of projected window.

 

We first used a sheet of same material for backprojection we have on our big screens but found it a bit too dark and ended up using a lightgray paper instead. The pics shows it lighter then in real life. Note also the vid is taken from start of runway and shows heavy groundclutter

 

the .zip is a (very) short video of the scope in action.

 

Cheers

Gus

Fil 2016-12-06 12 13 27.zip

Edited December 6, 2016 by Duckling

[RAZBAM_ELMO]

Looks tits dude. Would be a great alternative rather than a full flatscreen display or smaller screens. If this works in dcs you might be opening up a pretty good can of worms.

 

Sent from my SM-G900W8 using Tapatalk

[BravoYankee4]

Great idea. I have plans for doing something similar in a future Viggen cockpit build for the VID and perhaps the radar scope.

 

For the VID I have considered using the seeker from an old VHS camcorder.

[Hansolo]

Great idea Gus. Thanks for sharing :thumbup:

 

Cheers

Hans

[BravoYankee4]

That forum on simulatorgruppen, is that a public forum or a specific group related to your simulator?

[Highspeed1964]

Put a Cougar MFD around that and you'd be golden! At least I would think so. :)

 

Highspeed

[Thadiun Okona]

Sweet, this was the fist use I thought of when pico projectors became a thing.

 

This approach makes much more sense to me than trying to hack an oscilloscope crt, plus a whole lot more versatile.

 

I'm surprised there aren't more examples of this, would be a better way to handle mfd's in cases where the bezels butt right up against other instruments and don't have room for lcd's without fudging panel layout.

 

One could probably use a mirror to reduce the throw length in half if necessary, or also a larger projector to rear project multiple instruments at the same time the way people use big lcd's for full panels.

[Duckling]

That forum on simulatorgruppen, is that a public forum or a specific group related to your simulator?

 

It's an internal forum within VästeråsFlygMuseum. Couldn't find any of my old original pics so I grabbed that instead

 

..I have plans for doing something similar in a future Viggen cockpit build for the VID and perhaps the radar scope.

One more that eagerly await LNS latest baby :-) Right behind you here but I think another build currently at home will get me ejected by Wify. We (Museum) been searching for 37 cabin (any version) for some years now but still no luck. The objects in our show area is 'sadly' in a no touch status. A bit envy of our closest collegues Swesim & Novelair here.

 

Put a Cougar MFD around that and you'd be golden! At least I would think so.

Highspeed

:-) would be an option but it's a big no-no in our case, strive for as close to the real thing as possible, existing but not in place is the front bezel with moving "ILS" needels and some other stuff.

 

..would be a better way to handle mfd's in cases where the bezels butt right up against other instruments and don't have room for lcd's without fudging panel layout.

True for avoiding pocketing the MIP for LCDs ofcouse. The main pain using back projection are to avoid reflections, light leakage from outside, space required behind the screen, low intencity and set of focus so yes, it depends on the rig. Me personal I'd go for a TFT anytime where possible but I have the same problem as 'Warhog' for the RWR. I got nowhere possible to squize in a 4:3 monitor to cover the 3" RWR whithout cutting my frame or movings the sorrounding instruments. This option might fit

 

 

Cheers

Gus

[Warhog]

Thank you Gus, the pics are great. That's pretty much what I had been thinking about doing if all else fails. I had also considered using a smaller display and then use a fresnel lens in front of it to magnify the image to the size I require.

 

Has no one built the correct size RWR yet without the use of a crt display?

 

Gus, what quality of projector do think one could use without spending a small fortune and still get an excellent image?

 

Thanks again for posting the pics.

[Deadman]

I had a company severial years ago willing to cut lcds to 5 &3 inch square. Price was $500.00 USD each do to the price and the company's horrible customer service reputation with other SIM builders orders were never made

[Duckling]

what quality of projector do think one could use without spending a small fortune and still get an excellent image?

Not sure where the breake-even is. The one in my pics is run in VGA and might be possible to enhance. In this case it's good enough but doubt it will be enough for the fine details on the RWR.

There several micro projs on ebay but prize is high for HD quility with nice functions and Lumen and lowres cheep one tend to be bigger than coud fit in a 3" RWR tube. Watch up for proj that needs to be controlled by knobs on the shell, kinda hard to reach when built in.

 

more viewports exported in high res dig into the GPU and CPU resources but for a good working standalone RWR it might be worth it. To bad SoftTH isn't supported on newer OS (or is it?)

 

would be fun to test a low cost micro proj and see the result, with and without a green filter without going broke before christmas :-)

 

I'll check if I can locate another proj for test setup and if someone beats me to it, please post some pics here

 

A custom cut screen as DM says would be the best ofcose but way out of my leage currently

[Hansolo]

Has no one built the correct size RWR yet without the use of a crt display?

 

Pegasus over at Viperpits has done one for their community but I don't think it will work for DCS. As far as I understand that system gets the information from BMS' shared memory whereas what we need is something for a video signal.

 

Cheers

Hans

[Warhog]

I contacted a fellow who takes oscilloscope tubes and turns them into clocks. He has also made some RWR units for other pit builders' The cost is $1000 for one unit. He does say that a bulk order will reduce the cost substantially. But I suspect it will still be out of reach for a majority of the builders here.

 

http://oscilloclock.com/gallery/3-inch-vga-display

 

The proof of concept has been done and all we need is someone here who has the expertise to step up and design the circuit boards for us. Once we have those it would be an easy task to solder them up.

 

3" CRT tubes run about $35-50 a piece. I'm sure the actual parts would not amount to more than $50-75. I would think a DIY kit that costs less than $200 would not be out of reach for most of us.

 

Of course, it's all meaningless without having someone who can design the boards and prepare a BOMs list.

[Duckling]

@hans: great info but I fail to locate currect thread in there, can you provide a link or thread ID on VP ?

@John: a board setup somewhere about 200$ whould be really good cost if achivable. Several instruments in scope. Long way there though and also potential risks with the high voltage needed to drive the CRT. Could be a bit hazardous for both self and pit if not shielded proper.

Link you posted to the "clockmaker" products seems robust and impressive.

Quiz if its doable on a DIY basis (out of my league here but I check with a wiz I know)

 

Cheers

/B-O

Edited December 14, 2016 by Duckling

[Hansolo]

Sure thing Gus; http://www.viperpits.org/smf/index.php/topic,9418.0.html

 

It would be great if it was possible to do DIY for about $200. I'd definitly be interested @Warhog :thumbup:

 

Cheers

Hans

[Duckling]

Found this, not sure if it's applicable or not...

http://www.electronixandmore.com/projects/vgatoscope/index.html

[Warhog]

Found this, not sure if it's applicable or not...

http://www.electronixandmore.com/projects/vgatoscope/index.html

 

That's some really impressive information Gus. Interesting, that other than a few OpAmps, I already have all of the parts in my inventory. I may try this and maybe bounce this off Mike Powell. See what he thinks. I do believe he had developed a proof of concept.

 

I'm just getting my ADI functional. Once it's off my desk I'll look into this and see how doable it is. I really like the idea of using a screen that's much more in keeping with the real thing. The high voltage isn't anything I'm at all concerned with unless it causes a great deal EMI.

 

In the mean time if anyone else has something to add, please feel free. It's going to be a problem we will all face assuming we want to keep everything as close to scale as possible.