TGeorge
Member
- 37
- 60
- 18
- Location
- Gardnerville, NV
My 2006 M1078 was acquired with all the bits and pieces for a complete CTIS system. These are currently residing in a box until I'm issued a month of sundays to unscramble them. In the mean time I've discovered airing up or deflating the "Single Super" tires can be a test of one's patience. I needed a shave by the time all 5 were at 85 PSI. 
To relieve this phenomena I decided to machine an adapter that would screw onto the valve stem on the rim, depress the schrader core, and allow for easy connection of a Quick Disconnect air line. I was first tempted to use one of the brass elbow fittings used with the CTIS system, but mine are brand new, bright and shiny and I didn't want to sacrifice one, and the elbows have no means to depress the schrader valve anyway.
Probably old news to many here, but the male threads on the valve stem are 3/8 x 32 TPI. That's a bit odd ball, but taps are available for ~$12-20 online. Cutting the interior ORing groove is a little tricky, but I have a Hardinge HLV toolroom lathe so it was not too bad. The threaded machine screw is turned down to about .090 at the tip and for the prototype (and likely one and only example of this to be produced by me) the machine screw allows adjustment of when the schrader is actually depressed relative to how far the body is screwed onto the od of the valve stem. The machine screw leaks a little bit, but no big deal.
It works! I can screw this gizmo on a tire, plug on an air hose and leave it. With a pressure reg the tire fills to the desired pressure un attended. (i.e. while I'm getting that badly needed shave)
Here a few pics, also pictured is the elbow from the CTIS system. I suspect one could achieve the same result by drilling and tapping one of these elbows for a "pin" to actuate the schrader, and then find some sort of adapter for 9/16 x 18 ORB to NPT for the air chuck fitting.
Tobin
To relieve this phenomena I decided to machine an adapter that would screw onto the valve stem on the rim, depress the schrader core, and allow for easy connection of a Quick Disconnect air line. I was first tempted to use one of the brass elbow fittings used with the CTIS system, but mine are brand new, bright and shiny and I didn't want to sacrifice one, and the elbows have no means to depress the schrader valve anyway.
Probably old news to many here, but the male threads on the valve stem are 3/8 x 32 TPI. That's a bit odd ball, but taps are available for ~$12-20 online. Cutting the interior ORing groove is a little tricky, but I have a Hardinge HLV toolroom lathe so it was not too bad. The threaded machine screw is turned down to about .090 at the tip and for the prototype (and likely one and only example of this to be produced by me) the machine screw allows adjustment of when the schrader is actually depressed relative to how far the body is screwed onto the od of the valve stem. The machine screw leaks a little bit, but no big deal.
It works! I can screw this gizmo on a tire, plug on an air hose and leave it. With a pressure reg the tire fills to the desired pressure un attended. (i.e. while I'm getting that badly needed shave)
Here a few pics, also pictured is the elbow from the CTIS system. I suspect one could achieve the same result by drilling and tapping one of these elbows for a "pin" to actuate the schrader, and then find some sort of adapter for 9/16 x 18 ORB to NPT for the air chuck fitting.
Tobin
