Roee Kalinsky's RV-7A Project

2005.07.10: (2.0) Cut the aluminum and steel tubes for the aileron and elevator pushrods.

2005.07.14: (3.0) Primed the insides of the pushrod tubes by sloshing with AKZO.  Also alodined and primed the machined aluminum end caps of the pushrods.  Later in the day, started installing the end caps.  Fit on most was tight, so I chilled the end caps in the freezer and heated the ends of the tubes to make the best of expansion and contraction.  This, along with some gentle taps with a mallet did the trick.  Started riveting some of the end caps using a tube drilling jig I got from Spruce.

2005.07.15: (2.0) Installed a few more of the end caps.  Two to go.

2005.07.16: (1.0) Finished installing the control tube end caps.

2005.08.04: (1.0) Bored out the inner diameter of the brass bushings for the control sticks and aileron bell cranks.  Used Vay's lathe and a 1/4" reamer bit from Cleveland Tools.

2005.08.05: (2.0) Fitting the bushings: Shortened the length of the bushings to slightly longer (less than 0.0015") than the sleeves of the sticks and aileron bell cranks.  I'm not thrilled with this design, as there will always be a little slop in the sticks because the bushings must be slightly longer than the sleeves.  Also, there's some difference between the outer diameters of the bushings and the inner diameter of the sleeves, both of which were cut to final size by Van's.  Will try using grease to fill the void.

My technique for squaring and shortening these bushings (and other tubes, spacers, etc.) is to chuck the tube in the drill press and put some 100 grit garnet sand paper over particle board on the drill press's work surface.  This lathe-like setup guarantees a square edge and allows me to remove material in very small increments.

2005.08.09: (0.5) Made the W-929 aileron bell crank spacers.  Fitted them precisely using the technique described above.

2005.08.15: (0.5) Purchased some Dow Corning Molykote G-4700 "Extreme Pressure Synthetic Grease" from McMaster-Carr.  Used it to lubricate the brass bushings with good results.  The sticks have smooth action, and any slop has become almost imperceptible.

2005.08.15: (1.0) Fitted the F-665 control column push rod to the control column assy.  DWG 38 top left corner shows a dimension callout of 18 7/8" center-to-center of the rod end bearings.  But using this dimension causes the sticks to be tilted inward, i.e. toward each other at the top, in the neutral position.  I think they should be parallel as shown on DWG 38 view A-A, which requires the dimension callout be shortened to approx 18 5/8".  Will run this by Van's tech support.

2005.08.16: (1.0) Fitting the WD-610 control column to the fuselage.  First test fit showed that a total of just under four (4) AN960-10 washers are needed on the outside of the bearings.  However, three (3) AN960-10 washers and one (1) AN960-10L washer is still shy.  I'll need to either grind down a washer of fabricate a shim to get this just right.

2005.09.04: (1.0) With Stacey's help, alodined the elevator bell crank pieces and spacers.

2005.09.07: (1.0) Sprayed AKZO on the elevator bell crank pieces and spacers.  [also brake pedals, but here I'll log 1.0 h attributed to primary flight control parts]

2005.09.07: (1.0) Riveted the elevator bell crank and test-fit in the airplane.

2006.01.03: (1.0) Cleaned, abraded, and sprayed AKZO on the outside of the push rod tubes.

2007.04.17: (1.5) Removed the F-633 control column mounts from the fuselage so that I can cut out material called out in the plans for "optional weight savings".  I suppose that for the QB factory, "optional" means "skip it".  For me, it's worth the effort.  Every ounce counts.  Now to be clear, I fully expect that my airplane will come in on the average to slightly heavy side because of the powerplant and other equipment I plan to install.  The tradeoff of weight for functionality is pervasive throughout any aircraft design.  What I don't want to do though, is carry around dead weight just because someone didn't want to spend a couple of extra hours in the shop.

Cut the 1/2" holes (1/4" corner radius) using a unibit in the drill press.  Then spent some quality time with the band saw (it doesn't cut through 1/4" aluminum very easily, and generates a lot of heat, so I had to go little by little).  Then some more quality time with the files.  One done, one to go.

2007.04.21: (3.0) Finished trimming and cleaning up the control column mounts.

Sprayed AKZO on them, while the bearings are carefully masked off.  Installed them back in the fuselage.

2007.07.01: (2.0) I discovered several problems with my elevator bell crank.  1) The "yoke" ends were way too narrow.  They were approx 0.4" wide (inner), and they needed to accept 0.5" rod end bearings.  I was unable to adjust them sufficently and keep the yokes parallel.  2) The flange bearing had a fair amount of slop.  Other RV builders have reported this, and according to Van's it's not a problem, but it just doesn't seems like the amount of slop is excessive.

I decided to order parts and make a new bell crank.  This time I adjusted the bends before riveting so that the yokes came out exactly 0.5" wide (inner).  I also extended the shim further down toward the flange bearing, which will eventually allow me to attach another control rod closer to the axis of rotation for the auto-pilot.

At the end of the day, it came out fine except that the new bearing had just as much slop.  I guess it's really just a shitty bearing.