Archive for April, 2006

Riveted one wing bottom skin

Sunday, April 30th, 2006

Fellow KC-area builder Scott came by this afternoon to help rivet the outer bottom skins onto the wings, which is a task I've been procrastinating on for a while.

I had the long skinny arms so I got to buck all the rivets. Long sleeves are a must for this job. Also, this picture makes me hungry for Cozy burgers.

We planned to get both wings done in a couple hours, but we ended up taking all afternoon to get only one wing finished. We'll do the other one some other weekend.

This one didn't turn out too bad, although there are some dings and smilies here and there (especially back by the rear spar where it's hard to buck). Paint will hide them though. We only had to drill out two rivets, both of which were due to us misreading the callouts and using rivets that were too short.

Tank attach hardware

Sunday, April 30th, 2006

This morning I fabricated the parts that strengthen the fuselage where the fuel tank attach bolts come through the side skins. There's a big bracket attached to the nose of each fuel tank root rib, each of which bolts to another big bracket that sticks out of the side of the fuselage about midway between the spar and the firewall, and those brackets bolt to the forward cabin bulkhead through these angles and spacers:

The holes where all this stuff attaches were already dimpled and filled with rivets in my quickbuild kit. Apparently the quickbuilders got a little carried away. I just drilled the rivets out.

Here are the angles and spacers all match drilled to the fuselage skins and each other. You can't really see it in the photo, but I dimpled the thin spacer and machine countersunk the thick one, to let them lay down properly over the top of the already-dimpled skin and bulkhead.

Paper dolls

Tuesday, April 25th, 2006

I was too tired to work much on the plane, so I read ahead in the plans a bit. Looks like the mating of the wings is coming up not too long from now. I measured the plane and the garage, then made little paper cutouts to see if I'll be able to get both wings on and keep the airplane completely inside the garage. Sadly, no – even if I arrange things diagonally it won't all quite fit. One wing will have to protrude outside instead. Darn.

Still a few things to do until I get to that point, though.

Flap actuator

Sunday, April 23rd, 2006

Here's a collection of pieces that had to be fabricated for the flap motor mount:

The flap channel gets fitted thusly. The plans call for the joint plate at the top to be bent to an angle of 151.8°. Yeah, whatever – we're not building the space shuttle here. I just adjusted the bend angle until everything fit and drilled it in place.

Here's a shot of the rear side of the flap channel, where the motor pivot bolt goes through. The angle bracket is a little crooked, but that's how the motor geometry worked out. I've seen this on other builders' sites so I don't think it's a problem.

The motor can run the flaps through the entire range of motion without binding or rubbing anywhere. This is up:

This is down:

I got the side panels mostly fitted before calling it a day. With everything in place the flap motor has a little house to live in. I still need to deburr the side panels.

On the left side, you have to notch the side panel to clear the pivot bolt head. I clamped a piece of scrap aluminum to the edge of the cover and used a unibit, which worked well.

Flap actuator safety hole

Wednesday, April 19th, 2006

The only thing I got done tonight was drilling this little hole at an angle through the end of the flap actuator. In the photo, you can also see the first hole I tried to drill. The bit broke off in the hole and I had no way to get it out, so I had to start another hole. The end of the actuator was also kind of scraped up after all this, so I sprayed some more black enamel on it.

The idea is that you put safety wire through here and it prevents the jam nut from backing out as the flaps go up and down. I'm dubious that this will work very well, so I used permanent threadlocker on the rod end bearing and jam nut when I threaded them into the actuator.