We were working on the fuselage door for our Model Esp. The power wire for the spotlight came out of the back of the light and went into the door. We looked everywhere for the wire to emerge from the door to obtain its power. Not even a hole for a lost wire anywhere.
Inside of Esp door
We removed the door panel to discover – one wire going to each metal hinge. Too funny! Clever way to power the light.
One wire to each hinge
The guy that made the cockpit door was proud of his workmanship and provided his autograph on the inside of the wood door panel. Does anyone recognize his signature?
Signature of the guy that built our Esp cockpit door.
He also numbered the door. We guess that there was some hand fitting involved with the doors. The #274 perhaps was intended to go with Esp S/N 274, but our trainer is S/N 374. That may be one little mystery that we never figure out.
We built a Meikraft Model of the Link Blue Box Trainer. It is tiny – 1/72 scale. Easily fits in a 3” diameter dome. Lots of hidden detail inside the fuselage like rudder pedals, yoke, an instrument panel, and even wood trim. Ours is #171 of 550. The kits are out of production, but show up on ebay.com from time-to-time.
After all the bellow rebuilding, lubrication, and reassembly; the moment of the first turning motor test arrived. We could not believe it when the motor jumped into action with just a small vacuum from a vacuum cleaner hose held near to the port. Clockwise with one port, counterclockwise with the other. It is great fun to watch the sliding valves sequence the bellows. We decided to skip the timing alignment for the time being – sometimes it’s best to quit while you’re ahead.
As we started to become familiar with our new Blue Box and how it was supposed to work, we needed to decide how faithfully to the original we could restore it. We went through each subsystem, checked to see if it existed in our trainer, and to what level it could be restored. We felt that a total faithful restoration was beyond us because components such as wax capacitors, selenium rectifiers, porcelain switches, etc. were bad due to age or just plain worn out; exact replacements no longer exist. Phenolic is used throughout the trainer. Cloth-covered wire, real rubber, real leather, and no plastic make it hard to faithfully replace parts in today’s world of available materials. This trainer was missing key pieces such as the wind drift mechanism, connectors, and even the spindle. We hope to restore it to at least some level of flyable. For a functional system, we felt that some level of compromise was in order. We settled on using everything original that we could, but were willing to substitute modern materials and components where necessary. Our rule-of-thumb is “if today’s technician needed to get the system ready to train a pilot, what minimum compromises would he make in order to make it functional?” We also want the system to look nice, so modern paint, glues, etc. are in order.
Original Tobe Deutschmann motor condenser VS replacement
The very first subsystem we tried to restore was the vacuum turbine. And the first irreplaceable component turned out to be its Tobe Deutchmann dual noise-suppression condenser (left side of picture). We measured this big old wax capacitor — zero microfarads. We substituted two small modern caps. More about the turbine is discussed in the “Blue Box restoration hints” pages.
