9/16/2007
Another long work day, and even MORE pictures!
I started this morning by installing the rod end bearings in the elevator push tube, then fit it in the fuselage. This is fairly straightforward, the main thing being getting the bellcrank level.
Since this is just a trial fitting, I did not install it with all the hardware. Looks like I'll need several washers per side or fab up spacers to tighten things up a bit.
I was surprised how far in each rod end bearing needed to go to fit properly. This is a good thing though...Van's says that AT LEAST half of the threads MUST be engaged to prevent one end from threading itself out. It has happened. I have about three quarters of each bearing engaged, so I'm in good shape. I removed the tube, tightened the jam nuts, and torque sealed them. It's back up in the airplane storage room resting quietly now.
Next I started on the manual trim cable installation. Yep, MANUAL trim. Seems most builders are opting for electric everything these days, and I don't blame anyone for going that route. It's easier in operation. I just like manual things...flaps, pitch trim, aileron trim (coming soon!)...nothing electronic to go haywire.
Anyway, the trim cable that is used needs to be modified a bit so the rapid push-pull function is made inop. This would allow the pitch trim to function too rapidly, and more than likely cause airframe damage. Don't want that! To do this, first the rubber button is removed. It's glued in place, and is quite the PITA to remove. Here's how it comes from Van's-
I used that little screw driver to pry the rubber out (not easy), being careful not to damage the plastic knob.
The plunger is removed, that eliminates the push button function, and leaves only the threaded vernier function.
I simply need to find a one inch cover for the handle to make it look nice.
I hadn't yet drilled the hole in the front spar of the HS for the trim cable to pass thru, so I measured and drilled that hole.
Then it was time to start routing the cable from the cabin to the tail. It starts at the 704 bulkhead, and is a tight fit thru all the snap bushings.
It ran nice and easy all the way to the rear spar of the HS, when I hit a small roadblock. The hole that it's supposed to fit thru isn't quite the needed 7/16". The threads came thru just fine, but the casing is slightly bigger.
So I backed it out a bit, and very carefully used a thin Unibit to enlarge it just enough for it to fit thru the hole. There is no room for a snap bushing here, so I'll use some silicone rubber to keep it from rubbing.
I searched and searched for the little bag that had the manual trim hardware in it, and finally came across it in the place where I knew I'd remember (but forgot). There is a little nut that is welded to a piece of steel that makes the anchor for the cable. This is riveted to the trim cable cover.
The plans do call for universal head solid rivets here, but I really didn't see the need. I used MSP42 high strength blind rivets instead. These are not flush, but have less of a protrusion in to the air stream than universal rivets do.
Here it is all hooked up, and functioning! I haven't measured the allowed travel yet, but by eyeballing it, it looks to be pretty close to the limits.
I will probably figure out a way to put some sort of faring there...we'll see.
Then I moved on to the vertical stabilizer. First, the F-781bracket is clamped in place temporarily.
Then I trimmed the VS spar at the bottom, per plans. Why they have you wait until now to do this is beyond me...
The VS then gets clamped to the fuselage with a variety of clamps.
I hadn't yet made the F-712D elevator up stop, and the kicker is that my stupid bandsaw blade snapped yesterday. It was BRAND NEW! I'll be calling Carbide.com tomorrow to see what's up with this. So, I had to cut and shape this by hand. I know, cry for me, will ya?
Back to the rear of the airplane...I had a heck of a time getting the VS to measure out equally. I'd get it close then move it the wrong way, or to far in the proper direction. Frustrating. How many clamps, and what is the variety that I used to keep this thing in place? Here ya go!
With everything checked probably ten times, I drilled the holes thru the VS and elevator up stop.
I went ahead and drilled those holes first, so I still have to drill the bolt holes thru the longerons, and the rivet holes thru the aft deck. I didn't do anything with the front spar attachment today, and I need to get a washer in place to set the 1/4" left offset of the VS. You'll see what I mean tomorrow. I may trim the 'up stop' a bit more as well since it overhangs the spar by a quarter inch or so.
What a great weekend of RV work!
5.75 hours