New Tools, (Jan 30th, 2003)

This is a handy drill guide for drilling this dozens of piano-hinges

Making this tool took only a few minutes and will save hours of marking and centerpunching rivet locations

This is the way I use the tools

All these unreachable close-edge rivet locations caused me sleepless nights during the last year. Then came my internet builder-buddy Mervin Friesen in play. He travelled hundreds of miles in Canada finding a hardware shop selling this nandy tool:

It's a very simple mechanism, but it works (however it is not known in "Old Europe" :-))

Here you can see the very slim making of this tool (the right/top position is the riveting position). All rivets not closer than 1/4" (6.3mm) placed to a corner can be pulled.

This is another 'mission impossible'

Aileron hinge at the counterweight position. There's no way to rivet this locations. Even my ny new tool will refuse work here. Besides: the connecting U-cahannel in-between the counterweight holders will block any rivet at the rear side.

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Forward Fuselage Floor, (Jan 19th, 2003)

There are a lot of channels and gussets buried below the seat pan.

The trick is to place all the channels nicely perpendicular. I pilot-drilled and clecoe'd only a few holes, then removed the complete contraption from the airframe and final-drilled it. The rear seatpan attach channel looks quite flimsy when not installed, however all this gussets make it rather strong. I suppose this assembly is inteded to avoid harm to the pilot on a belly landing (hey, where are the three greens on my panel???)

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Air Vent, (Jan 11th, 2003)

Update

Have re-bent the instrument tilt angle from 60 degrees to 70 degrees. Its ~much~ better now. Angle of view is more convenient, more space for far-forward extending instruments. If any of you quick-kit builders intend to do this -dont! The geometry of the glareshield will change!

I installed the air vents today

The plate carrying the vent replaces the original instrument panel corner plates. I bolted the instrument panel assembly at the wing attach angle and upper longeron. This way i can easily remove the complete panel when necessary (it's a hell of a job to crawl into the forward fuse and work overhead at cables and tubes). Also the headphone jacks are placed at this plate. The plans show the attach plate in front of the wing attach angle, mine is behind. For some strage reason the parts fit much better this way.

This shows my design (left) and the original Sonex at the right.

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Spar Tunnel, (Jan 5th, 2003)

The way I'm working seems quite chaotic. This comes because I started at dozens of different sub-projects (started just what I had material available). Now things from all ends are going together.

Assembly of this component is not easy if it is fixed inside of the tight cockpit confinement. I pilot drilled only a fey easy-to reach locations, then disassembled the whole carboodle, then re-assembled again on the worktable and finished drilling.

View forward on the spar tunnel. Better drill all locations to be dimpled undersized (about 2.8mm). This will provide a nice tight hole ;) after the dinpling job.

Since some time I take another shortcut: disassembly/deburring/re-assembly can be skipped here. I firstly pilot drill then final drill then disassemble and deburr. This does not compromize the quality of the work in any way.

Pitot Tube Mount

This is the way I mount the pitot tube:

No, it's not crooked, the tube is intentionally tilted to -12 degrees. Why should someone do such a thing? Reason is a systematic failure which is 'build in' in every pitut tube. The higher the angle of attack the larger becomes the deviation of IAS from the real airspeed. The bad aspect of this is that at low airspeeds (= high AOAs) the tube indicates a ~too high~ speed (which could be deadly). See chart for '0' degrees.

If you install the tube with an negative offset angle this effect can be compensated for. See chart for '-12' degrees. The TAS error at stallspeed is zero! Small errors at crusie speed is of no concern. The overall error is greatly reduced.

This applys only for the 'Winter' tube. I don't know if the original Sonex design would also benefit from such an installation (which due to the curvature of the forward wing contour is even tilted slighly !positive!).

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Root Rib Attach Angles (Jan 4th, 2003)

Made these today

This angles are a bit tricky, because the mating flanges are tilted 4 deg (3.9 to be precise ;) to one side. The flat surface should be one straight plain (top picture). This only can be accomplished if one angle is pretty close to 86 degrees and the corresponding one 94 degrees. It takes ~a lot~ of force to open or close the angles by only 4 degrees! (the markings show that the holes at the short flanges are match-drilled)