M

Maxrate

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I have debated weather to throw a live grenade in or not but here goes....

I'm getting to the point in the wing construction where I need to make a decision on avionics components. I have had the opportunity to fly behind the GRT glass and have seen the Dynon at last years Sun-n-fun and both are impressive. The Dynon has a dedicated pitot for airspeed and AOA, whereas the GRT allows pretty much any pitot setup as far as I can see. The features on the integrated SkyView Autopilot are more impressive than the Honeywell I fly behind at work, however I don't know the track record of their system. The GRT that I got some stick time in had the TruTrack AP and it worked flawlessly. I know that the TruTrack is bullet proof. I realize that this is a bit of a Ford vs Chevy discussion. Both are priced comparatively.

I believe it will probably be several years before I'm finished with my 7 and at the pace these companies are moving a lot can change in that time. It looks like AP servo brackets can be changed after the wing is closed up, but your stuck with your choice of Pitot tube. Is there anything else to consider at this point in the wing construction.....

Thank's...."standing by for incoming" :D
 
Call SteinAir

Stein sells all the major glass displays and has a real good feel for what "fits" in each situation. He and his organization have a high level of integrity, experience, and are not adverse to do it yourself installers either. It would be worth a phone call. See...

http://www.steinair.com


FWIW. I built an RV6 in the late 1990,s and installed a TruTrak autopilot. The autopilot was still under development so I left the bottom skin off the wing for over a year while I built the rest of the airframe and the unit was being developed. The wing is very stable with one skin off, does not need any support, and I put the servo and wiring in later after I made some final decisions on equipment. I did install conduits in the fuselage & both wings for wiring chases during construction. Some were unused at first flight but all have at least one wire in them now after six years of flying. Things just changed and the conduits were very handy.

Dick DeCramer
RV6 N500DD 400 hrs.flying
RV8 Fuselage...Canoe stage
Northfield, MN
 
2 things...

1. Why do you think you need to pick your pitot tube now? Run the tube, and an electric wire if you want heat. Installing a pitot tube later is not a huge problem.
2. Pick your electronics as late in the process as possible. You'll have selections that don't even exist yet - regardless of which way you go :eek:
 
Pitot selection

1. Why do you think you need to pick your pitot tube now? Run the tube, and an electric wire if you want heat. Installing a pitot tube later is not a huge problem.
Click to expand...

Dennis, Good question! I know that Dynon sells a dedicated pitot setup for their system that has an integrated AOA feed. If I knew in advance that I was going with Dynon I would need their pitot.

I know of one 8 out there with the GRT glass that has an inexpensive Piper blade pitot installed and it works great with his set up. Money well saved. If he had decided to go with Dynon, I don't see how he could have with the Piper pitot. I'm just trying to cover all the bases before cutting holes in the wing for good.

Thank's for the input.
 
If it is truely going to be several years before you finish, I would simply hold off, and work intelligently around some general assumptions. I'm doing a super slow (for me) build -8, and I've already built two sets of full assemblies for different magnetometers and AHRS. I'm keeping my options fully open, but will be very ready when the time comes.
 
I'm speaking from inexperience here, but I thought the only special thing about Dynon's Pitot tube was their AOA. Meaning if you want to use the Dynon AOA you have to use their Pitot Tube.

Pt (total pressure) is Pt no matter which tube it's flowing through. Looking quickly through the Dynon manual, it looks like you just need Pt (from any pitot tube) and then Pt at 45? (or whatever angle their combined tube measures) for the AOA.

I thought I saw someone on the forums use the Van's pitot, and then roll their own second tube for the 45? (AOA) portion.

I would be very surprised if Dynon's air data unit's measurement of Pt requires their own Pitot.
 
I've agonized over this same question for a while, and I'm in the exact same build phase. Here's what I came up with.

Buy the dynon pitot tube. It'll work with everything, and should you go dynon you're set. And it's the same price as everything else too, and will work with the Gretz mount.

I'm going to hold off on the autopilot roll servo. I can install it later on. Plus I'm used to using just altitude hold at work anyway.
 
Scott I think thats the way I'm going to need to build up the wing at this point.

Dick said.....
I left the bottom skin off the wing for over a year while I built the rest of the airframe and the unit was being developed. The wing is very stable with one skin off
Click to expand...

Sounds like a great way to proceed. As the picture becomes clearer I will have many more options to future install items with the wing still partially open. I was not aware that you could take the wing out of the jig and put it in the storage rack like this.
 
Plus I'm used to using just altitude hold at work anyway.
Click to expand...

Ahhhh a real pilot..:D Thats a great idea about just installing the mount at this point and deciding on the Pitot later.
 
GRT can use any pitot. Its a function of software and pitot that makes it work. I have been flying an HX for 1.5 years. LOVE IT
 
On my RV-6 wings I ran two lines out to the pitot tube. Right now I have a cessna Pitot, but I can upgrade to a Dynon unit easily if I want. The pitots will fit the same mount, just run two lines out and cap one if you don't go with the dynon. The Piper blade pitot mounts differently, so using that pitot will limit your options a bit, or make it more work to change out systems later.

I know Mel rolled his own AOA pitot and he says it works great with the dynon.
 
There is nothing magic about the Dynon AOA pitot. Mel made his own. Easy to do. I did not install my pitot until I was at the airport in final assembly mode. I did however install the line inside the wing during assembly.
 
ColoCardinal said:
Do any of you know if the Dynon pitot can be used in lieu of the Advanced AOA?
Click to expand...

IT does a similiar function as the AFS AOA, only if you have an EFIS that supports that funtion. The only ones that I'm aware of are from Dynon.

AFS has the AOA function integrated into their EFIS, so you don't need to also purchase the complete AOA kit.

GRT has a software emulated AOA function.
 
FWIW...

...in my -10, I have the TruTrak autopilot directed by the 430W. The Dynons stand alone and if they go TU, the autopilot will still fly.

Putting all your eggs in one basket should be considered, IMO. If the Skyview goes on strike...no autopilot....from another pro-pilot:)

Best,
 
Thanks Bob. So can a Dynon AOA pitot be plugged into an AFS EFIS and a AFS AOA into a Dynon?
The reason I ask is that the AFS AOA option is crazy expensive for a couple pieces of tubing and you still need a pitot.
 
ColoCardinal said:
Thanks Bob. So can a Dynon AOA pitot be plugged into an AFS EFIS and a AFS AOA into a Dynon?
The reason I ask is that the AFS AOA option is crazy expensive for a couple pieces of tubing and you still need a pitot.
Click to expand...

It depends on how they work. The Dynon AOA simply has a second tube with a port at an angle to the forward-facing pitot, and the EFIS measures the difference in pressure between them to determine the angle of attack. You still have to run a calibration exercise to get it to report accurately in your installation.

If the AFS system works the same way, it MIGHT work - but someone will have to try the experiment.

As mentioned above, you could duplicate the effect of the Dynon AOA pitot yourself, but it might not be easy to get the heated version duplicated as easily.

FWIW, my first experimental's pitot tube was a piece of forward-facing 1/8" AN tubing connected to an AN fitting. Worked just dandy provided you didn't walk into it during your walkaround on the ground - and even then, it cost only pennies and a few momentst to replace (if you couldn't just bend it straight).
 
ColoCardinal said:
Thanks Bob. So can a Dynon AOA pitot be plugged into an AFS EFIS and a AFS AOA into a Dynon?
The reason I ask is that the AFS AOA option is crazy expensive for a couple pieces of tubing and you still need a pitot.
Click to expand...

Not really.....

You can use the Dynon Pitot with the AFS Efis, but the AOA isn't compatible between vendors.

However, you can use the AFS AOA as a standalone unit with any EFIS vendor. With that said, the AFS AOA is only integrated with their EFIS.

Dynon, AFS, and GRT all use different approaches to generate AOA and they aren't interchangeable.

bob
 
I found that using the true track auto Pilot has a head to it. I think around $1600 for the units but the with Dynon the head is built into the EFIS unit so you'll save about $750 bucks.
Ron in Oregon
 
As a slight aside.

When you calibrate the Dynon AOA, you go through a sequence of pitching manoeuvres followed by stalls in various configurations.

Now - picture the scene, they want a full power stall :D

OK, put it into test timer mode, apply full power slowly and start pitching up. At an estimated 45 degrees nose up, I started laughing, my older Brother started squealing like a girl and it still was going up.

So, I pulled a little more, gave up and pressed the button :)

Huge fun for me !
 
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