MacNab

MacNab

Well Known Member
I saw this today on another forum and thought I'd share the discovery. This is just what I've been waiting for.

Virtual HUD

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I see that these guys are at Mud n' Fun. Does anyone there have a report for us?
 
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...and the best part is...

That Bill Steele, the inventor, is an RV builder! He was my riveting partner during my SportAir sheet metal workshop. At the time he was thinking of building an RV-8.
 
petehowell said:
Veni, vidi, velcro - I came, I saw, I stuck around... very nice!!
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I try to change that auto-signature about once a month. As they say in the advertising business - 'Watch this Space!'

I'm hoping that Bill (or one of his Licensee's) will come up with a version of this that is a permanent installation instead of portable. I suspect that the portable unit is operated strictly from GPS data. I would prefer to use real air data for airspeed, altitude, and vertical speed. I would also like to see this thing shrunk down considerably in size so that maybe just the projector system is sticking an inch or two out of the top of the glare shield - it's only a matter of time, and I have the patience of Job - not!
 
Cute idea...

It's a cute idea, it paints a HUD image onto the backside of the spinning prop with a laser. Presumably, it controls the laser to only be lit when it is pointed at the back side of the propeller, so the beam never goes beyond the propeller disk. Since you can make the laser as strong as you want then, you solve the problem of the image getting washed out on bright sunlight.

Disadvantage is that it won't give you an image focused at infinity which a traditional HUD would do - your eyes will have to focus close to read the HUD information and then have to refocus far to see beyond the propeller. Not a big disadvantage, as the propeller disk is a few feet away from you, unlike the control panel. Another disadvantage is that the image will be limited to where the propeller disk is - no image to the top left of your field of view. And if the propeller stops turning, then you lose the image completely. Also, though not so much a problem with GA aircraft, since the image is not focused at infinity, it can't quite be made to line up visual cues with the view out the cockpit - so symbology to show where the runway is, and synthetic vision, won't work as well as it could.

Nonetheless, a smart idea worth considering.

--JCB
 
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groucho said:
What happens when your engine quits? (i.e. when it'd be REALLY nice to have that HUD)
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Like I said, if the prop stops you have no image. Also, you will have no HUD image while you are sitting on the ground with the engine off.

Of course, it is conceivable that it will paint an image on the stationary blade - how useful that might be, I don't know.

I wonder what the flicker is like? Prop spinning at 2400 RPM means 4800 blades per minute, means 40 blades per second... idling at 1200 RPM means 20 per second...

Actually, I sort of like this idea because it should be able to give you as bright a picture as you want in daylight. But I assume that it involves moving/spinning mirrors to get the beam to scan and those mirrors have to be synced with the prop somehow. Perhaps he has a scheme where a lower intensity laser scans for each prop blade rising and that triggers the scanning of the laser for the rest of the picture... just guessing... for all the trouble of syncing the image to the prop I have a hard time understanding how it saves money over a conventional HUD which has no moving parts, just lenses and a projection quality CRT...

In case anyone cares, this is one of the HUDs I once worked on...

http://www.cmcelectronics.ca/En/Prodserv/Milav/milav_dcs_hud_sphawk_en.html

--JCB
 
I fly with a hud at work. When I saw this the first thing I thought was "I don't want that stupid combiner in my airplane." Then I saw he used the back of the prop arc. Brilliant!

The fact that it's not at infinity is less of a trade off than the issue of having that stupid combiner in the way. Some day there will be a mid-air with a non squawking airplane and a contributing factor will be the combiner distraction (not necessarily hud data). We haven't had one yet thanks to TCAS. The person who might not like the focus distance is someone heavy into the presbyopia years without correction for the distance to the prop arc. Any degree of accommodation remaining and I see this as a non-issue. Not that many diopters from 5 ft to infinity.
 
groucho said:
What happens when your engine quits? (i.e. when it'd be REALLY nice to have that HUD)
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Nomex touched on this already, but my thought is that just because the engine quit doesn't mean the prop stops. A windmilling prop at say 800 RPM still gives 1600 blades per minute (or 2400 if you have a cool sexy 3 blade...) for a refresh rate of 26.7 Hz, which is most likely better than you get from MS Flight Sim.

I think it's cool and I want one!
 
sprucemoose said:
Nomex touched on this already, but my thought is that just because the engine quit doesn't mean the prop stops. A windmilling prop at say 800 RPM still gives 1600 blades per minute (or 2400 if you have a cool sexy 3 blade...) for a refresh rate of 26.7 Hz, which is most likely better than you get from MS Flight Sim.

I think it's cool and I want one!
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If the engine seizes up is what I was thinking about. Most times when the enigne stops yes, you will still have a windmilling prop and an image.
 
Nomex - I see that you and I once worked on the same equipment. The world is smaller than we think... ;-)

My kids gave me a neat little toy airplane for Christmas. Its propeller spins via electric motor, and one blade features an LED display. When the prop is spinning this LED display is used to produce a stationary image of a clock. Very cool, low-tech and could be useful as a technology for HUD. Plus it makes neat airplane engine sounds so I don't have to make them myself! ;-)
 
VirtualHUD at Sun-n-Fun

Hey Guys,

I know some of you were talking about this a while ago, but we will be back at Sun-n-Fun this year. (Oshkosh, too!)

We've launched our first product called the NightVU (portable) and will be showing off our next version, the ForwardVU which is designed just for us experimental folks. (I'm building an 8A, so I have the perfect test platform.)

Anyway, look us up if you down there and let me know that you saw this here. I love to chat about RVs.

BTW... most of your questions can be answered by our FAQ on the site (virtualhud.com), but if not, feel free to send me an e-mail and I'll answer them here.

Bill Steele
Building an RV-8A - N131LL
 
I recall that several years ago at Oshkosh there was a vendor hawking a HUD. This was before the EFIS explosion, as I recall, and there apparently wasn't much of a market for it. It was small and pretty cool-looking.

I used to have a Corvette that projected digital instrumentation onto the windshield. Loved it.

I can't help but wonder if someone out there is working on a HUD that couples with a Dynon EFIS ... I'd be happy to be a beta tester. :D
 
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