Lift Indicator Probe, Oct. 21th, 2001

The first development sample of the indicator probe is ready.

It's made of three layers of 4mm thick Plexiglass. The 45 degree drillings at the front and top are a bit tricky. The drill wants to wander away from the material. Maybe I'll make a second model later.

Next step is data acquisition. I'll put the probe ontop a broomstick, hold the gadget out of the car window and take readings at different speeds and angle of attacks. So stay tuned.



Lift Indicator Faceplate, July 24th, 2001

I made a simple Corel Draw 8 image of the red-yellow-green colored faceplate. Every better printing shop should be able to print it at the rear side of the Minihelic's faceplate (which, to my advantage is plain white).



I'll build a Total Lift Indicator!, July 20th, 2001

Why ~build~ such an instrument?

The instrument consists of a differential pressure probe (0.5" X 1" X 6" 6061-T6 flat bar with four holes drilled in it) plus a Dwyer(R) Series 5000 Minihelic II differential pressure gauge of 0..2" water coloum (or equivalent of 0..500 Pascal for all those living in metric world).

The gauge looks suitable for the job. The case is made of fiber reinforced plastic. Outside diameter is 73.9mm, case diameter is 65.5mm and depth is 55.8mm (including tube studs which are 6.3mm in outside diameter). Weight is about 120 grams (6 Oz). The instrument will be mounted from the rear using a bracket.

So it will NOT fit into a standard aircraft-instrument hole! Do not unscrew the rear part (as I did). The instrument may loose its zero adjustment (which isn't a big problem, read on...).

The pointer is quite sensible (which is usual for such a sensitive instrument).

The front bezel holding the plastic glass can be unscrewed (with quite a lot of force).

The front bezel is sealed against the case with an O-ring (1) (which is responsible for resistance of removal). Once the instrument is open, you can adjust the pointer's zero position using a small allen wrench (2) which is provided with the instrument. This will be necessary for the Sonex's 60 deg tilted instrument panel.

The instrument face is fixed with two small phillips-head screws. So another face can be installed easily.


Instrument with face removed. Arrows locate the reception of the phillips screwas.


This instrument fits ~perfectly~ into a 'unox' champignon mushroom soup can. Give it a try if your US tomatoe soup cans are also usable ;)))

... to be continued...