RobertGary1 Posted December 1, 2014 Report Posted December 1, 2014 I don't see a tech list so I'll post this here. I'm looking for a replacement for this microswitch that screws into the back of my AI and provides a warning channel on my voice annunciator for vacuum. I've tried a couple gyro houses and a couple of junk yards but no luck thus far. Any recommendation for a source for this or an alternative? It appears that Sigmatek may no longer be interested in making these. -Robert
Marauder Posted December 1, 2014 Report Posted December 1, 2014 Did the silver solder crack? I gave up looking for a replacement back in the 1990s and went with the Precise Flight vacuum warning gizmo.
RobertGary1 Posted December 1, 2014 Author Report Posted December 1, 2014 Did the silver solder crack? I gave up looking for a replacement back in the 1990s and went with the Precise Flight vacuum warning gizmo. Possibly, I haven't inspected it in that detail. But the entire body of the switch has come off from the screw. So I now have a hole in my vacuum system, my AI tumbles, etc. Trying to get this engine install finished so I can get a permit to fly the plane somewhere that I can annual it inside a hanger. Installing the engine on a ramp has not been awesome. But I don't want to fly it with a hole in the vacuum system. -Robert
MB65E Posted December 1, 2014 Report Posted December 1, 2014 The Vaccume system is not required for VFR flight. I know you probably want it corrected, but no need to chase down a ferry permit. sticky notes work great! I removed my VAC system completely! Good luck! -Matt
Guest Posted December 1, 2014 Report Posted December 1, 2014 You could just install a standard 1/8" NPT plug in the hole to cure the vacuum leak. The Sigma Tec vacuum switch can be dis assembled and repaired with a bit of effort. Clarence
PeytonM Posted December 24, 2014 Report Posted December 24, 2014 Have you called LASAR (www.LASAR.com)?
RobertGary1 Posted December 25, 2014 Author Report Posted December 25, 2014 No. I tried several wreckers and couldn't find it. So I just plugged it for now so I can proceed with the permit to fly the plane out to a place I can swing the gear and annual it. In the ground run the new engine seems super strong.
RobertGary1 Posted December 25, 2014 Author Report Posted December 25, 2014 I should mention that it's not something segmatek makes any more so anyone who has one has it left over. I'll probably instead just buy an $80 warning light system from spruce but hook it to the annunciator instead of a light. I did try some gyro shops who would normally specialize in this type of thing.
Cruiser Posted December 25, 2014 Report Posted December 25, 2014 the metal can is easily pulled off the threaded nipple if not handled carefully. If this is your problem, it can be repaired. Reform the metal can to the base of the fitting and use a little JB weld around the seam. Let it set overnight. Carefully re-install. ..... Good as new.
RobertGary1 Posted December 25, 2014 Author Report Posted December 25, 2014 This is what it looks like now. Oddly it's also now open meaning it's reporting vacuum in range. So it's also incorrectly indicating.
N601RX Posted December 26, 2014 Report Posted December 26, 2014 I have taken one of those apart, cleaned and adjusted and it worked fine afterwards. The adjustment process was trial and error using an ohm meter, calibrated pressure reference and hand pump. There were some indents around the top that held it together. If I remember correctly a new one was around $450. After removing the internals you should be able to solder it back together and then reassemble. There is a rubber diaphragm and spring inside that must be removed first.
RobertGary1 Posted December 26, 2014 Author Report Posted December 26, 2014 I might replace it with this for $90... http://www.aircraftspruce.com/catalog/inpages/vacuumwarning.php I'd just hook it to the annunciator channel instead of the light provided. I also have an extra port on my vac manifold so I wouldn't need to T a line. -Robert
Cruiser Posted December 26, 2014 Report Posted December 26, 2014 This is what it looks like now. Oddly it's also now open meaning it's reporting vacuum in range. So it's also incorrectly indicating. yep, looks like it has been repaired before. just clean off the resin/glue from around the threaded nipple, press the metal can back on and seal it again.
Guest Posted December 26, 2014 Report Posted December 26, 2014 This is what it looks like now. Oddly it's also now open meaning it's reporting vacuum in range. So it's also incorrectly indicating. Robert, With a bit of effort you can fix it. I chuck the fitting in a lathe and turn it down, removing the glue etc. then turn it a bit further .010-.015 making the pilot a little longer. Carefully pry the 3 dimples open allowing removal of the switch from the aluminum body. Carefully tap the end of the body flat and remove old glue. Insert the now lengthened pilot of the fitting through the body, set it on a steel bench fitting end down and peen the pilot from inside the body until it is tight. Now reinsert the switch into the body gently squeezing the switch against the rubber seal, re peen the 3 dimples to hold the switch in place. Now check and adjust the switch per the maintenance manual process. Clarence
Marauder Posted December 26, 2014 Report Posted December 26, 2014 This is what it looks like now. Oddly it's also now open meaning it's reporting vacuum in range. So it's also incorrectly indicating. Robert -- this is exactly how mine failed. The mechanics replaced it with a Precise Flight unit.
Recommended Posts