Bob & Ron's vintage Link Trainer (aka Blue Box) restoration adventures
This looks like a circus, but is just the cheapest Amazon spray paint booth over top our C-3 blue box. We only punched one hole in the tent and perhaps shortened a couple poles setting it up, but it seems to work just fine. Got a spray coat of sealer on today, and a coat of UV protector – that’s the shiny grey stuff. Next week we apply a couple coats of white butyrate dope.
We are getting ready to recover our C-3 hood. It had been repainted green and is now cracking badly. As we prepared to remove the old cloth, we turned it over to discover a couple unique features. Two brackets support a shortened clipboard with the last pilot’s faded notes. Also, a convenient “NO SMOKING” under the hood sign.
We started replacing worn-out fabric on our C-3 with Ceconite. Rick (right) is a jack of all trades and has been helping with Blue Box refurbishment for years. After ripping off the old fabric, sanding the wood and priming it with poly, we asked Leroy (left) if he would be our tutor. Leroy is an airplane fabric expert. He recovered Wright Patterson AFB Training SPO’s Blue Box many years ago; and he recovered the Memphis Belle’s ailerons with authentic cotton for the Air Force Museum. Leroy is trying to teach us tricks of the fabric trade.
We were working on our C-3. We finally got the directional gyro working; after 3 disassembles / reassembles. All of our fuselage instruments were working except for the clock, for the first time. Then Rick said “Do you smell something?” Things went from best-ever to bad in an instant. Smoke billowed out of the control box as we fumbled for the OFF switch. Wax from the burning autosyn transformer dripped into a pool inside the control box. We opened the building doors to let the smoke outside.
With trainers approaching 80 years old, it’s no wonder many substitutions have been made over the years. Here’s one we have seen several times. Original Blue Box trainers frequently used #6-40 screws; the most common #6 machine screw today is a #6-32. When a #6 machine screw just doesn’t fit right – it may be the wrong thread.
A similar problem occurs with small set screws; Blue Boxes often use Bristol or spline. When standard Allen wrenches don’t fit, get out a magnifying glass and see if a Bristol is in order.