Control Horn (July, 31th, 2004)

The control horn assembly now waits for 4 weeks to be bolted together. The horizontal play of the stick should be only a few hungrets of an millimeter (thickness of a sheet of papaer). That means the compelte assembly has to be assembled and properly clamped together for drilling.

This is the way I clamped one side (dual controls) together. Unfortunately there is no way to fit this kaboodle under the drillpress (red arrow marks drill position). Another problem is, after removing the powdercoading to fit the bronce bushings, the stick itself now sits very sloppy on the torque shaft. I hope the bolt's clamping pressure will cure this.

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Bronze Bushings (July, 13th, 2004)

Last Weekend I removed the powder-coating from the rudder pedal linkage. Today I carefully sanded the bronze bushings of the stick mechanics. Removing this black powder-coating was a real pain.

Took me three hours for the four bushing to make them tightly fit - free of any play. I cannot understand how others leave the black stuff on the tubes. In the control-stick frame the bushings are not really press-fit, so I will locktite them in.

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Pivot-Blocks (July, 10th, 2004)

This is one of the worst summers - so far. Lots of rain, clouds and it's shivering cold. I had to postpone the aerobatics license I intended to complete on a Zlin 526 this year, same with my new favourite waste of time - an AFF course of skydiving, which I started here . PPL license runs out in August and I have only 4 flight hours this year (required are 12 hours for a renewal).

This Forstner drillbit works well for the pivot-block holes. It was 26mm diameter when I bought it. I grinded down to 25.5mm. This is still too tight for the powder-coated 1" steel tubes. So I will remove the powder coating where the tubes go through the blocks.

Result of a Saturday morning's work

I used oil-filled cast nylon for the blocks - a very tough material with an extremely low friction index. Drilling at very slow speed is actually not difficult, but the material makes large volumes of chips. I had to remove the chips a dozen times for each hole. During that the Forstner drillbit became boiling hot. I used plain water for cooling.