Steve Koerner wrote on 8/15/2019 4:59 PM:
As it turns out, I just recently addressed this issue for the JS3 tailwheel.. The retractable tailwheel is quite small. The air volume is such that any attempt to put a gauge on it will drop the pressure quit a lot. Also being so small, I found it hard to judge by eye.

The method I came up with uses a machinist outside caliper to measure tire bulge. It's easily understood with these pictures:

https://photos.app.goo.gl/uyt8BgJWRSKKHuj6A

There's a certain skill required to use the machinist caliper -- the key is zero spring pressure. Accuracy is about 5 PSI.

I was able to accomplish the calibration without any reference to dimensional measurements (inches or mm).

Since this was just devised a couple weeks before the OP came on with his question, it hasn't had much field testing. We'll see if this is a good solution after I've used it awhile.

Clever! But, are there solid tire wheels that could replace the pneumatic one? Or
get it filled with foam?

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1
- "Transponders in Sailplanes - Dec 2014a" also ADS-B, PCAS, Flarm

http://soaringsafety.org/prevention/...anes-2014A.pdf