aviator79's build

[aviator79]

I have the Laker Leading Edge trimmed and ready to install, but decided I want to prime the spars even though I live in about the dryest of dry climates. It's cheap and easy to do it now. So I had to order some primer. I also decided that I wanted to wait until the wing was covered to do the wingtip so that I can fit it up well.

So I decided I'd get a start on the flaperon, but when I opened a box from Aircraft Spruce, the dimple dies I'd ordered for flush riveting the trailing edges weren't there. One phone call and they are sending them out. So I thought I could move on with the end rib installation, but my end rib didn't fit in the end of the flaperon on account of a welding error. So, an email and some pictures to Debra, and a replacement is on the way.

That left me pretty much stuck in the mud for making progress on the wing, so I got started on the fuselage, which was really enjoyable work. I got the aileron, elevator, and flap controls installed. The only slight frustration is that I had more resistance in the pitch axis of the control column than I would have liked. What was strange is that it only started to bind up when I tightened any fastener on the right side bracket. So I removed the whole thing and clamped the left (delrin) bearing to the workbench, and noticed that when moving the stick fore and aft, the bracket rotated slightly around its vertical axis. This indicated either a bent bolt or a hole that wasn't straight. I replaced the bolt, which didn't change anything. I recalled that the pre-fabbed bracket was pretty rough from the factory, and I suspected that the hole perhaps wasn't straight, which would misalign the bearing halves. I disassembled the whole enchilada, and very carefully removed a small amount of material from the pre-fab bracket. I reassembled, and the situation was much improved, but still not perfect. So I chucked up the bushing in a drill press and sanded it down with 600 grit. I repeated this process several times, removing only the tiniest bit of material at each iteration until the bushing slipped easily into the bearing, and the control column gave smooth motion with the bracket clamped firmly to the workbench. This was a lot of effort, but I'm not going to compromise on the nicely balanced controls that I experienced in Idaho.

I also got the floor boards trimmed and drilled, and they'll get their second coat of varnish this afternoon.

LLE fitting and trimming:





Control column bracket as-received:



Flight control assembly:





Floorboard fit-up:


--Brian

[Esser]

Sounds like you got it licked Brian but I had to put a washer between my bracket and the fuselage on one of my bolts that completely freed up the same binding you experienced.

[aviator79]

I got the right flaperon finished. Drilled the brackets and removed. Installed the LLE, and glued in optional trailing edge stiffeners. The right wing is ready to cover! I'll do that after I take the SportAir workshop in Phoenix Feb 10th-11th.

I got the center console mostly finished. Rudder control horns modified, and the rudder pedal assemblies mostly complete. My long #30 drill bit went dull, so I need another one to finish riveting together the second rudder pedal assembly.

Some wisdom earned this week:
-There is a note when assembling the flap handle to make sure that you get full travel of the slider before assembling. This note is not present in the instructions for the rudder adjustment handles. As it happens, my flap handle had full travel, so I had forgotten this tidbit when assembling the rudder adjustment handle. When I got the center console on, I couldn't get the detent pin to disengage from the detents. It took me a few minutes to figure out why. The result was drilling out the securing pin to disassemble the handle and take some material off the slider. Now I need to procure a new securing pin before I can reassemble the second handle and finish the center console. I believe (hope) they sell these tension pins at the local hardware store.
-On the LLE, the instructions recommend two clecos in each rib, and 5 in the #1 and # 10. When I do the left wing, I'll use 5 clecos at the number 5 rib where the two LLE halves meet, and maybe even in all the ribs. As it is, it worked fine, but the fiberglass doesn't sit perfectly against the ribs everywhere, and I just think the result would have been better with more clamping. There was some "waviness" in the trailing edge of the LLE, which is very minor as long as it's even while the hysol cures, so I weighed it down.

Pictures:





Note the lack of full travel of slider. I hadn't assembled the detent pin in this side yet. But in the one in the background, it is fit up to the detent bracket, but won't disengage.


Rudder pedal assembly:

[aviator79]

One other piece of wisdom learned:
When you fit up the floorboards, lay the center console in place, lest you end up drilling eight holes in the aft floorboards instead of four. I placed the aft ones to line up pleasingly with the middle ones, and the center console did not fit between them at the aft end. I had to trim them on the outsides to move them outward to fit the center console, requiring me to redrill the mounting holes and fill the old ones. I wish I had time and money to build two of these things, because I think I could do a nicer job the second time around. I'm already worried that my plane will only fly in circles because my left wing will be built much better than the right.

[rosslr]

HI Brian,

I haven't commented much on your posts because I haven't anything of value to add but just wanted to say that I find your descriptions really clear ( as are the photos) and although I have finished building, I know many following you are going to find your posts a treasure trove of practical wisdom. The warts and all reports are great - makes me feel human! (I have some nice wrinkles at the back of the LLE! - doesn't effect anything as far as I know)

It looks like its going along well with your build and I look forward to more posts.

Best

ross

[aviator79]

I'm trying to hold myself to a pretty high standard of craftsmanship, so it stings a little bit when I discover that I need to rework something. The slider travel was one where I kicked myself. The LLE fiberglass is simply not going to fit perfect. I tried several ways to get rid of the wave at the trailing edge, but at the end of the day, it's just not quite the same shape as the wing, so something has to give somewhere. I've seen some people scallop the edge which probably mitigates or masks the wave somewhat. Weighing it down assures that the amount of wave stays the same between each false rib, and prevents the wave from lifting the trailing edge away from the false ribs while the hysol cures. I figure it'll certainly be less wavy with the LLE than without.

[Brandon Petersen]

Make sure to support the center of the wing of you're installing the LLE on a rotisserie. I like to fit and install the LLE with the wing on a rotisserie in the vertical orientation.

Have fun!
B

[JoeRuscito]

Congrats! So stoked for you!!

[aviator79]

For those interested in performance, here are some numbers derived from EFIS flight data:
Density Altitude: 8000
Flight test weight: 1175 lbs.
Flaps: 1/2 position
Ground Roll: 550'
Distance to clear 50' obstacle: 1017'.
Climb rate: 1300 fpm at 71 mph.

These numbers are with an inexperienced Kitfox pilot making no attempt to extract maximum performance. I'm pretty happy with the performance, and look forward to developing the skill required to expand the envelope.

[Clark in AZ]

Nice Brian! Thanks for posting the numbers. Refresh my memory on your engine again? Non standard 914 turbo, correct? HP?

Great Job!

Clark