Heated AOA/Pitot

Cars10

New Member
Joined
Aug 19, 2007
Messages
1
Started installing the heated pitot, s/n P1245. First a question, then a suggestions:

Q: I put a resistance meter to all three blue/org/blk leads as well as the aluminum tubes and the AOA body itself. I found no measurable resistance on anything (analog meter, not very accurate). Is this normal, that everything seems to be shorted out to everything? Update: With a digital meter, I found some resistance, but only 5.1 Ohms Or-Blu, 2.6 Ohms Blk-Or and Blk-Blu, and about the same between any wires and the tubes or body. Is this normal?

Sug.: I have the Gretz mount. According to the instructions we are to drill and tap through 4 bosses for 6-32 screws. The heater wires are placed in the worst possible location, right between the two front bosses. With care, I avoided drilling into the wires, but this placement makes tapping useable threads impossible. 6-32 taps have a 1/4" lead-in before it acchieves the full-size thread. So now, due to the proximity of the wires, it requires you to choose between making an incomplete thread, or letting the tap run into the wires. I chose the former, hoping that the screw and some muscle would cut the final threads, but the screw broke and I had to drill out the screw. I'm left with an oversize hole. Probably have to go with a larger screw size for this hole. But the wires are still there. VERY frustrating. Bottom line: PLEASE redesign the location of the wires, to somewhere less problematic. OR: Provide drilled and tapped holes in the boss before Dynon's final assembly.

Please suggest course of action.

Cars10
 

dynonsupport

Dynon Technical Support
Staff member
Joined
Mar 23, 2005
Messages
13,226
The resistances you're seeing are normal.

As for the pitot issue - if you're ultimately unable to work out a mechanical solution without hitting the wires, give us a call at 425-402-0433 and we'll see what we can do. We'll look into better positioning of those wires as we go forward as well.
 

MikeB

New Member
Joined
Feb 23, 2007
Messages
7
Sounds like you are using a plug or taper tap, which is generally what you get in the off the shelf tap and die kits. You need to buy a "Bottom Tap" to tap those holes. It doesn't have the 1/4" lead in.

Check out http://en.wikipedia.org/wiki/Taps_and_dies for the differences.

http://www.mscdirect.com/ has bottoming taps for 6-32 threads, and they are priced reasonably.

Good Luck,
Mike Bullock
 
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