Larry Champion RV-8 (Slow Build) - Page 4.

October 16, 2008:  I went over to help Larry Champion again with his RV-8 for a couple of hours this past Thursday evening.  The task was to check the alignment of the main landing gear legs and their axles to check for toe-in or toe-out.  When I began to suspect a problem with a "twist" in the LEFT landing gear leg, I got the idea of clamping a piece of aluminum angle to the gear leg near the axles.  The black marks are 12 inches apart on this angle.

Over on the other angle, the angle length is ONLY 12 inches.  By measuring the distance from the forward end of this angle, to the forward black mark on the angle above, then comparing that distance with the aft end of the angle with the corresponding mark on the angle above, the proof of a twisted landing gear leg was confirmed. 

And here is the result of the error showing a toe-in condition on one axle versus the other axle being perpendicular to the center line of the fuselage.  This first photo is of the axle with the problem.  The string is not parallel with the wooden block or the axle.

Over on the side that is true, the string follows the face of the wooden block and is parallel to the axle itself.

By the end of the measurements, it was determined there would be no drilling of gear leg attachment blocks tonight.  A call to Van's Aircraft tech support would follow the next day.

October 18, 2008: Saturday comes and I am now armed with information from a conversation with Van's Aircraft tech expert, Ken.  He was amazed that when I helped Wendell measure these same parameters that no correcting "axle shims" were needed on Wendell's quick-build kit.  Ken liked my idea of the two clamped aluminum angles to determine the twist error in the landing gear legs.

For this photo, we put one AN-4 spacer washer on each of the forward bolts that hold the axle to the gear leg.  The thickness of that washer was measured and the spacing between the forward and aft bolts holding the axle to the gear leg.  A quick arc tangent calculator entry showed the angle to be corrected by about 2.6 degrees.   The result was a "banjo tight" string across the face of the blocks on both axles when they are both equidistant from a center-line reference point near the tail of the fuselage!  Victory!  At that point I went upstairs with Larry and had him log onto the Van's Aircraft web site, showed him the 1-degree and half-degree axle shims made by Van's to correct the slight twist errors in the RV-8 gear legs.  He ordered TWO of the 1-degree shims and ONE of the half-degree shims to correct for the twist in the LEFT landing gear leg.  When they arrive and I return from my current road trip, the landing gear will get a final true alignment and the mounting holes will be drilled into the fuselage strong points of steel and aluminum of the gear leg towers.