[simpits-tech] Glitchy REAL altimeter in a Lear 25!

[Matt Bailey]

Watch the altimeter needle in this video:

https://www.youtube.com/watch?v=WRFAIxAUH0s

Sure bounces around a lot! This makes me feel a WHOLE lot better about
the 737 altimeters I did the software for a while back!

But it raises an interesting issue: the altimeter in this video appears
to be the same altimeter that's going in my Sabreliner. I had noticed
that this altimeter relies heavily on synchros (along with a rotary
shaft encoder for getting the altimeter in the right general "zip code",
so to speak), but none of the synchros are anywhere close to a 1:1
gearing to the needle....the needle makes several rotations to the
synchro's one rotation. I didn't see how the position sensing could ever
be precise enough to move this altimeter smoothly and accurately all the
time....apparently, it's not! I suppose once I finish up my synchro
interface to precisely read synchros, it will move about as smoothly as
the real thing, but I'd really like to make it better.

I may have to look into modifying the altimeter to accept a Hall sensor
(in rotary configuration) on a 1:1 relationship with the needle.

-- 
Matt Bailey

Keeping It Real:
Sabreliner 60 Flight Simulator
Serial # 306-61 - N1JX
http://sabrelinersim.com