New Product Announcing the eLogger V3!

[Yellowsierra]

Hey Bill,

Is the Version 3 about ready to ship? I really want a datalogger but dont want to buy the V2 since the V3 is coming out.

Thanks

Justin

[Socomon]

I thought I saw the date was pushed back to Dec. or January due to a manufacturing issue. Bill, please give us an update of when you expect you will have them and when Tower might have them.

Steve

[13brv3]

I noticed the Eagle tree web page just changed from Nov 15th to Nov 30th for availability.

Rusty

[billpa]

Hi All,

We are shipping the first (small) batch of eLogger V3's starting today. If you ordered one early in the preorder cycle, you should get yours this week.

Our next batch of eLoggers is due in at the end of November, and that should be enough to fill the orders we have right now.

Regards,

Bill, for Eagle Tree

[Socomon]

What about Tower?

[Yellowsierra]

I gave up on the V3 and just ordered the V2. I guess I will bye the V3 lator...

Justin

[numb_thumb]

Bill or anyone,

What's up with the theories about elogger that say you have to place the airspeed expanders in a neutral pressure area?

I can understand (although I'm yet to believe) that if you place the expander in a high pressure area (such as where there is direct flow of air) then you will get less numbers than actual.

However I don't understand how a low pressure environment could form inside the fuselage??? I have enough air intakes in all my planes for good ventilation. At high speeds a decent amount of air gets inside the fuselage to take away some of the heat.

In theory it would be awesome if the airspeed expander could read the air pressure the moment when it is turned on and store it and then use that as an baseline to calculate the airspeed when the plane gets in the air. This way we don't have to nit pick on things like low pressure, high pressure et al.

[dhares]

This is a long answer, but here goes. Airspeed is calculated using pressure differential. Reading atmospheric pressure on time on the ground isn't enough, since altitude and other things have a very real effect. In real airplanes, pitot tubes have pressure and static ports. See http://www.grc.nasa.gov/WWW/K-12/airplane/pitot.html for complete details. The difference between pressure on the two ports can be used to calculate airspeed. Bill made his life easier by using a sensor with an internal static port. He assumes that the static pressure port is seeing atmospheric pressure similar to what a real pitot tube's static port would read. Nice idea, but not realistic in electric models where we force air into the planes for cooling. I've used the following techniques to solve the problem:

1) Put the Microsensor and the pitot tube out on a wingtip. Put the sensor under the covering in a closed compartment and route the pressure line to it. The compartment is leaky enough that it will read atmospheric pressure without itself becoming pressurized.

2) Put the microsensor inside a small container of some sort. Run the wires and two tubes out of the container. One tube connects to the pressure sensor, the other just stops near the pressure sensor. Seal the container. Connect the tube going to the pressure sensor to the tube Bill gives you, and place it in the airstream. Run the other tube to a neutral pressure area. I can post a diagram/picture of this if anyone's interested.

These techniques get the airspeed to correpond to GPS airspeed within 5%, when compared to an FDR Pro flying in the same aiplane at the same time. Or just get an FDR Pro - they have both pressure and static ports so you can build and use a real pito tube.

[diver don]

Originally Posted by Socomon

What about Tower?

Is Tower on your list?

DD

[billpa]

Hi All,

Dave, thanks for the great writeup.

One additional method (sealing of the sensor) is covered in the "troubleshooting" of the airspeed microsensor manual.

http://www.eagletreesystems.com/Supp...icrosensor.pdf

This looks a lot more difficult than it is - takes about 2 minutes to do.

Regards,

Bill, for Eagle Tree

[Socomon]

Originally Posted by diver don

Is Tower on your list?

DD

I'm not sure if that is a question addressed to me or to Eagle Tree. Tower's website indicates that they will be getting the V3 product in at some point. but Bill has been unwilling so far to comment as to when.

Steve

[billpa]

Hi Steve,

Sorry for the confusion. The first large production run of eLogger V3's is due in-house at the end of November, and all distributor and direct orders will be filled at that time.

Regards,

Bill, for Eagle Tree

[Socomon]

Thank you Bill. My assuption based on that would be that Tower should have them early to mid December. I am hoping to get a 100 amp wire-leads version from them.

Steve

[dhares]

Originally Posted by billpa

Hi All,

Dave, thanks for the great writeup.

One additional method (sealing of the sensor) is covered in the "troubleshooting" of the airspeed microsensor manual.

http://www.eagletreesystems.com/Supp...icrosensor.pdf

This looks a lot more difficult than it is - takes about 2 minutes to do.

Regards,

Bill, for Eagle Tree

I tried the approach in the manual first. It works OK, but I had trouble getting a tube under the shrink wrap without damaging it (the shrink wrap). I finally used a piece of your pitot tube materal to slide in, not flexible hose. That gave me a connection point too. I dabbed everything up with silicon caulk and got results +/- 20% of GPS. I stripped silicon and heatshrink and put everything inside a pill container and got +/- 5% of GPS. I'd recommend the pill bottle approach if you can tolerate the size and 1/4 oz weight. One other benefit ... with the most pill bottles you can slide the altimeter expander right in too, back to back with the airspeed sensor, and let it use the same static pressure. Otherwise you have to deal with it too.

Dave

[13brv3]

Guess what showed up in the mail today

I haven't tried it yet, but it looks great

Thanks,
Rusty