Saturday, June 30, 2018

One step forward....

Actually, no steps forward for a long time. It's been pretty quiet on here for a while now. I finished assembling the short block on the engine by adding the flywheel seal, oil pump, etc. and bagged the whole thing to keep humidity out while I worked on the heads. I took a break to work on some Christmas presents on the lathe, and then I broke the lathe, so that needed repair... after that I started trying to recondition the heads myself. I don't think that was a mistake; the way I went about it was a little less than ideal, which caused more problems than it solved. That's all for another post though; this weekend I'm back at the fuselage, and making some serious progress... backwards!

Two years ago, I received the canopy I ordered. There's a long story of assumptions, misinformation, betrayal, and pretty poor customer service, but the bottom line is I've spent the last two years trying to figure out if I can even use the canopy or if I need to buy another one. It's a Dragonfly canopy, but the folks who made it insisted on molding it out of thicker acrylic than the design calls for. As a result, it bends a lot less than I anticipated, and trying to force it to fit has been difficult. Along the way, I realized how uncomfortable the seat is, because of the angle the seat back rests at. All it needs is to lean a few inches back to be much better.

So the plan was to cut out and replace the existing crossmember and seat braces, leaving the plywood shelf in place.


Here I've got the line marked, and just in case the sides got any squirrelly ideas, I put a clamp around the old crossmember to keep the dimensions stable. I clamped a straightedge on my line and used a utility knife to score through the plywood. I removed a chunk from my new line forward to the old crossmember. 


Looking good so far. The next step is to cut and fit the new crossmember and glue it in place. I just need to look underneath to mark the angles, and...


Whoops. There's an unexpected turn of events! The longeron doubler doesn't go quite as far as I thought it did. This just became a much bigger project.......

So I'll be replacing the plywood after all. I don't have any pieces that size left, but I can still cut the new crossmember and put it a little further forward. I had hoped to gain 3.5", but I ended up settling for 2.75". It didn't take long to fit the new member, which installed quite nicely.


With that in place, I cut out the old crossmember and seat supports, sanded and planed the remaining bits of wood away. 

I cut and fit new seat members, glued them in place, and left them to cure. 


This was enough for now. I'll still need to add all of the gusset blocks, but my goal this weekend was to get the plane to a point where I could sit inside and take measurements on total height required above my head as well as instrument panel height. I'll do that tomorrow when the glue's had more time to set up. Once I get those numbers I can finish the templates for the canopy frame, which I'l work on when I come back down in a few weeks. In the meantime, I'll keep working on the valve seats.

1 comment: