Sat Aug 08 2020

Flap actuator mount and baggage area overhead light

I had mentioned that the aft end of the elevator pushrod tunnel cover was going to need a bit of clearance for the rivet heads at the aft end. Sure enough.

Looks better now.

I started working on mounting the flap actuator. This tube needs cut down to 13/32 or .406 long. Just clamping it lightly in the vise wasn't working...it would just pivot down when I tried to cut. I didn't want to clamp it more for fear of flattening the little tube.

So I made a little tubing clamp block from a scrap of hardwood. Allowed me to clamp it solidly.

Because this little tube is so short, I wasn't able to use my go-to method for getting tubes down to the right length and with square ends. I usually chuck the tube in a hand drill and hold it against the spinning disc sander. Instead, I used Van's recommended approach...chuck it in the drill press and lower the spindle to press the end of the tube on a file laid on the table. It was slow going, but yielded a nice result. I think the finish of the ends is actually better than the way I do it.

I positioned the little angle bracket in assembly with the flap actuator in order to match drill it to the flap actuator channel.

I rarely use these little spring stops, but wanted to be sure I didn't drill through too far, catch the bit on the castle nut, and break it off.

Hrm...after drilling, I could see that the bolt used as a pivot for the flap actuator wasn't square to the channel. You can see it peeking out from behind my square in this pic. It's peeking out more on the left than teh right.

I decided to make up a new angle bracket and try that again. Of course, the angle stock wasn't square.

I clamped it in the vise and pried on it a bit.

Better.

Here's the new bracket...profiled, but no holes yet.

Instead of just drilling the 1/4" hole in to the dimension specified on the plans, I decided to transfer the location from the existing hole in the flange of the channel. I don't have any transfer punches, so I made this one from a piece of steel rod.

Lots of clamps and spacer blocks were needed to hold everything in position before I could whack the transfer punch with a small hammer.

Okay, that worked really well. After drilling the 1/4" hole, I clamped the bracket in assembly (ensuring that the bolt was square to the sides of the channel) and match drilled the three rivet holes.

Well, I need to prime that bracket and little tube, but I'm not mixing up a batch of primer just for that. I decided to work on the overhead lighting for the baggage area. I made these parts a while back. Unfortunately, when I drilled the row of holes which will mount the LED strip, I positioned them at a spot where the left edge clamp strip will interfere with the rivet heads.

I decided to just make a new plate and use the old one to transfer all the holes to the new plate. I found a piece of .025 scrap out of which I could re-make that cover plate.

Here's the new cover plate. BTW, this cover plate will cover the underside of the roll bar support channel. I flattened out all the dimpled holes on the old cover, clamped old and new together, and match drilled.

For mounting the LED strip, I had planned on making a joggled strip, but hadn't come to a good solution for making that strip. Perhaps I can just make a couple spacer strips instead of making a joggle bend. It looks like two layers of .040 thick should work.

I no longer have access to a large shear, so cutting long strips of aluminum is a hassle. I've tried snips, the router, and the nibbler. None are all that desirable. Snips and the nibbler tend to curl the resulting strip. Using the router, it's hard to control the width of the strip. I decided to try cutting with my circular saw. I clamped everything up, hooked up the vacuum and tripled up on eye protection. Earplugs, obviously.

I adjusted the blade to only cut through by, maybe, 1/16".

Well, that was a little scary. The blade caught a couple times. Nothing catastrophic happened, but you can see the off cut is a bit deformed.

Likewise on the panel. I don't think this approach is going to work. Maybe I'll re-think the joggle approach.