|
|
Post by shadowgunner on May 24, 2013 10:41:22 GMT 9
The IRST in operation, 100psi. It doesn't fully retract due to a broken seal inside the actuator. We are working on a resolution.
|
|
|
|
Post by Jim on May 24, 2013 11:30:01 GMT 9
The IRST in operation, 100psi. It doesn't fully retract due to a broken seal inside the actuator. We are working on a resolution. Not bad considering that those seals might well be 50 years old |
|
|
|
Post by ma1marv on May 24, 2013 23:23:14 GMT 9
WOW! That relly look good! I would suggest to lighten the load on the IR head by pulling the IR head, then disconnect the 499 unit (The cable between the head and the bulkhead) and remove the 499 unit all together. The hex head bolts should be 7/32 in size. We used a long 7/32 hex wrench to reach the aft mount bolts. This should lighten the load caused by the binding when the 499 is twisted when the IR head retracts. I'm going to guess that you cannot fire up the system anyway - so remove the extra bind, and the weight of the IR head should allow the full retraction. This would allow you not to go try and find a repair seal for the actutor valve. Next best hope is to go to the El Paso site and see if the owner of the six airframes there would allow you to remove an actuator and hope it works! MArv   |
|
|
|
Post by pat perry on May 25, 2013 0:03:17 GMT 9
Shadowgunner, Contact Ralph Robledo at CAM. He has a IR head on the F-106 there. I don't recall if they have it air operated or manually extended for Open Cockpit Days. Send me a PM if you need his contact info. Thanks, Pat P. PS: www.castleairmuseum.org/ Open Cockpit Day is Sunday May 26th 9 AM to 5 PM. |
|
|
|
Post by shadowgunner on May 25, 2013 1:18:23 GMT 9
I wasn't clear on the retraction problem. At the point where it stops in retraction, there is a physical restriction inside the valve. It is a mechanical "stop" at mid retraction; leaving about 2-3 inches of the ram still extended. With a screwdriver in contact with the actuator (in the absence of a stethoscope) one can hear the sound when the actuator bottoms out against the damaged seal/ring. It reminds me of a broken piston ring; but I don't know if this actuator used seals or rings. We are working on a resolution. There are a number of options. MA1Marv, I imagine it is a b**ch to get the actuator out.
Jim Mattison
|
|
|
|
Post by Jim on May 25, 2013 1:20:40 GMT 9
shadowgunner, both MArv and Pat P have great suggestions. Here is another for those seals, try local ACE hardware plumbing section, some of their seals are oil resistant. Also are suitable for air pressure use with less than 200PSI.....
|
|
|
|
Post by shadowgunner on May 25, 2013 1:23:27 GMT 9
here's a picture of the actuator in retraction to its fullest ability. this shows the point where it encounters internal interference.  |
|
|
|
Post by shadowgunner on May 25, 2013 1:28:01 GMT 9
Marv;
thanks for the guidance & suggestions.
Jim
|
|
|
|
Post by Jim on May 25, 2013 1:31:25 GMT 9
I wasn't clear on the retraction problem. At the point where it stops in retraction, there is a physical restriction inside the valve. It is a mechanical "stop" at mid retraction; leaving about 2-3 inches of the ram still extended. With a screwdriver in contact with the actuator (in the absence of a stethoscope) one can hear the sound when the actuator bottoms out against the damaged seal/ring. It reminds me of a broken piston ring; but I don't know if this actuator used seals or rings. We are working on a resolution. There are a number of options. MA1Marv, I imagine it is a b**ch to get the actuator out. Jim Mattison If you believe that the restriction is in the valve, then there could be a piece of an o ring that moves back and forth with operation and plugs up the "retract" port.. Had this same phenomenon with a T-bird and a landing gear hydraulic line that had been replaced and no retraction check made. The gear would retract, but one gear would only extend about a third of the way down. Pilot landed on other main and nose and held it off til the tip tank touched down. Lifted the wing and disconnected the hose, and down came the gear. A piece of rubber was travelling back and forth between the actuator and the selector valve.. |
|
|
|
Post by ma1marv on May 28, 2013 22:43:49 GMT 9
I just looked at the picture you posted and noticed the 499-02 plug! The new updated version of the 499 cable is installed. The flat wire pack seemed to take the movement during operation much better than the old rubberized version! I would still take the IR Head off and remove the 499. As for removing the actuator - I recall that putting it back in and hooking things up was much more of a problem! MArv |
|
|
|
Post by shadowgunner on May 30, 2013 8:28:01 GMT 9
Thanks guys, for the help. I had to use an interim solution; by disconnecting the rod end and tying it up out of the way. Doing so has allowed the IRST to be manually stowed; keeping the Starlings and yellow jackets out of the compartment. I am still researching how to remove the actuator; but, may have to just settle for a manually operated IRST. My intent was to show it off during display weekends and our annual airshow. Who knows, in time I may be able to come up with a 12v linear actuator or some kind of servo to operate it.  Jim |
|
