Tag: Blue Box

More speed Scotty

With the main bellows now rolling and pitching, we were hoping to get the ANT-18 off the ground.  But, with full throttle, we have no air speed, and no engine RPM.  We checked wiring to the primary instruments, cleaned the slip ring contacts, and various connector contacts till we got continuity.  Since the RPM cockpit instrument is operated pneumatically directly from the tachometer regulator bellows, we thought that was a good place to start troubleshooting.  That eliminated wiring and Telegon instruments as a potential problem, and let us concentrate on vacuum and linkage.  Our tachometer regulator bellows was very stiff.  We decided to restore both regulator bellows and the stall bellows since they were all stiff, and all related to air speed or engine RPM.

Outside of regulator bellows during restoration.

Straighten up and fly right

With vacuum applied to our newly refinished bellows, our ANT-18 was leaning badly to the left (or as our Navy buddy Jeff said “it is listing to port”).  We had to keep the yoke’s wheel at about 45 degrees to the right to counteract it.  After fixing all the leaks in the aileron pneumatics that we could find, we decided to adjust the aileron valve.  It took only a tiny adjustment of the torque linkage that goes to the center leaf of the aileron valve to correct the problem. 

While looking for aileron pneumatic leaks, we also restored the ANT-18’s rough air system.  Its key valves were leaking badly. 

What is a Jiggley ?

Here is a Link Trainer “Jiggley” action trading card.  After the bubble gum is gone, you have this great toy.  Jiggleys were made by the Model Airplane Company, Brooklyn, NY in 1950 and 1951.  They made several series of trading cards; Military, Cowboys, Circus, Weapons, Guns, etc.  Ours is No 45 from the Military Series 6  “Jiggleys”. 

Front of Link Trainer “Jiggley” trading card.

The Blue Box and his instructor are die cut punch outs.  You remove the background stencil that you can use to trace more “Jiggleys”.  Once the stencil is removed, there are two narrow strips of card in the back that connect the Blue Box and instructor together, each with a staple.  See the rusted staple popping through the orange Blue Box base, and the instructor’s pants?  You hold the strips, and jiggle them left and right, to see the Blue Box fly and the instructor scold the cadet pilot with his finger.  Too much fun. 

Back of Link Trainer “Jiggley” trading card.

I thought it odd that the instructions said “Replace Stencil to Pitch, Trade, Collect.”  Why “Pitch”?  Then I remembered how, when we were kids, we used to “pitch” baseball cards at recess to see who could get closest to a line or land it to tilt against the side of the school building.  Winner takes loser’s card.  Wow — that was a long time ago. 

Vacuum to the ANT-18’s fuselage

We recently added the second wing to our ANT-18. That made it look a lot better. We fixed a few wiring problems in the main control box, and replaced external power wiring. We installed our restored Telegon oscillator, and cleaned, lubricated, and tested the turbine. Like our other turbines, the Toby Deutschmann suppression condenser had to be replaced.

Broken vacuum connection between turbine and spindle.

The vacuum hose that connected our turbine to the spindle was broken in a couple places. The connection was unlike models Esp and C-3 whose hose is short and at the same height. The ANT-18 has an additional separate set of commutators hanging below the standard 28 rings. This assembly causes the vacuum entrance to the spindle to be much lower than the turbine’s vacuum source. Our vacuum connector was obviously not an original part; it consisted of several short pieces of 1-½” PVC pipe poorly glued together. We still don’t know what the original connection looked like. We decided it would be better to have a slightly longer hose with a smooth bend rather than the additional two sharp 90-degree corners introduced by the broken connector pipe. We ordered a hose that was ultra-flexible; however, it only came in bright blue or green. After a bit of sanding, primer, and flat black paint, it now looks like an old rubber hose.

New vacuum connection hose.
New vacuum connection between turbine and spindle.

We had to try it out, by turning on the turbine. We had just completed restoration of the turning motor, so that was in good shape. The pitch and roll bellows looked and felt pretty good, but as soon as vacuum was applied to the fuselage, the pneumatic cloth on the pitch bellows ripped. That’s the next task – rebuild the pitch and roll bellows.