Bob & Ron's vintage Link Trainer (aka Blue Box) restoration adventures
We recently refurbished the turn and bank indicator regulator bellows for our Blue Boxes. The regulated vacuum output is supplied to a gyro inside the turn section of the turn and bank indicator.
For more details, read the ‘turn and bank indicator regulator bellows’ section under ‘Restoration hints’ in the right column [scroll to bottom for cell phone] , or check out our video.
Update December 1, 2020. The bellows refurbishing did the trick. The turn and bank indicator is now working. Yea!
Our altimeter transmitter was stuck. We opened it up, cleaned the gears and oiled the bearings with synthetic clock oil. The Telegon transmitter motor is magnetically coupled to the gear box. Each side has a tiny Y-shaped magnet; the driving and receiving magnet are spaced about 050” apart as they spin. It’s hard to see in the picture; but the North side of the magnet is marked with a faded red stain. Details are shown in the “Altimeter transmitter” section of “Restoration hints”.
It’s not often that new material is written about the ol’ Link Trainer. The July issue of “Aeroplane Monthly” has a nice introductory article regarding the Blue Box. It includes some interesting facts, and new graphics depicting the trainer’s vacuum system and associated instruments. Ian Bott, a professional graphics designer in the U.K., researched the subject and created the pictorials. He did a nice job presenting a lot of info in a few column-inches. Check out “Aeroplane Monthly” (July 2020) and read a full-sized version of the article.
We ran across this unique hose splice while replacing some old brittle hoses on the ANT-18. Here is the hose we found connecting the roll valve to the East roll bellows. It separated at the splice. It had been repaired in a former life with a socket used as a hose connector. Too funny.
We received a good restoration hint from Charles who is rebuilding a turning motor for the Bayport Aerodrome, New York. He normally works on player pianos. He recommends replacing old leather nuts with plastic ones. Charles says that leather nuts supplied today are full of acid and he has had steel threaded rods destroyed in less than 10 years by them. He recommends plastic nuts with a ¼” hex head which look something like a leather nut.
They are available from Klann Organ Supply, www.klannorgan.com . They have a #50 center hole and will go on to most small threads. They tend to crack if the thread is too big so it is best to drill out the center hole to about 0.010” under the outside diameter of the threads you are going on to. #50 = 0.070”. A tip of the hat to Charles.