Dave’s RV-7A Building Log

I used the template in the plans to cut the slot in the side skin for the latch. I carefully positioned the template and used the center punch on each hole that needed to be drilled. After drilling the holes, I cut out the slots with a cutting wheel in the Dremel going very slowly and carefully. I finished up the slots with a small and then medium sized file. They turned out quite nicely. I clamped the latch assembly to the skin, but decided to re-evaluate the fit tomorrow with fresh eyes before drilling the holes through the assembly.

The latch is not 100% perfectly flush with the skin. At the front end it’s about 1/64″ inset from the skin. I can live with that. Ideally, Dan’s site wouldn’t have been down when I needed it last week, and I would have seen his suggestion to drill the pivot point hole in the angles from the latch rather than from the plans. No big deal, though. Overall the latch is looking very cool.

I drilled the blocks that hold the latch weldment to the F-705 and mounted everything in the fuselage. It works really smoothly. The next step is to tap the ends of a rod to make it into a push rod, but I don’t have the right size drill bit. I’m going to order a bunch of numbered bits that I need from probably McMaster-Carr.

I made the angles that hold the latch mechanism and made sure everything fit together. I also worked a little bit more on the canopy release mechanism. I keep debating about whether to put it in or not. I have most of the parts made, so I might as well. As Matthew pointed out, I can cut the hat section way down that the mechanism mounts to. That will help in case I need to cut through the subpanel for avionics.

I spent just a little time deburring the latch parts. The punching process leaves these things very rough.

Spent some time fabricating the parts for the canopy release. I made the pins by just cutting the shoulder bolts with a hack saw and rounding the ends with the grinding wheel. Drilling the holes in the ends of the steel rods was a little tricky, but I just started with the #40 bit and worked up to #12. Working with steel is definitely not fun. Using Dan’s method, I put a cut off wheel in the drill press and carefully cut the slots in the ends of the rods. It worked great. I deburred the slots with a file and did a test fit. I need to adjust the slots a little bit to make them work.

I spent a little time trying to figure out an alternative to having the release handle sticking out of the middle of the instrument panel. One idea I got elsewhere is to shoot the handle vertically down the subpanel. This looks better, but the handle isn’t accessible in flight. I’ve read a lot of discussion on the topic of whether it’s really possible to jettison the canopy in flight and whether that’s worthwhile. The pressure of the air over the canopy will make it very difficult to push the canopy off the plane. Unless the occupants are wearing parachutes, bailing out is not really a good option anyway. However, installing the handle is not very difficult, adds to peace of mind, and probably helps re-sale.

I’ll probably just install the release mechanism per the plans, but cut down the hat channel a bit so it doesn’t take up so much room behind the panel.

I drilled the spacers for the canopy hinge point following the instructions. It’s a complicated process of clamping together parts, starting a pilot hole, drilling on the drill press, etc. After I did that, I remembered another RV builder suggesting I try Jeff Bordelon’s method for drilling the hinge points. A few builders, Dan included, have had edge distance problems after drilling the fingers that come out of the canopy frame. Jeff’s approach solves that problem. Unfortunately, I’m already past the point of being able to use his method. I might be able to adjust the 1/4″ hole, so I’ll put off drilling that hole for a while.

I spent a little bit of time dipping into the finishing kit, finally. I pulled out some stock for the spacers that go in the hinge points and cut a couple of pieces to size.

I drilled and blind riveted the ends on the push tube, thus closing out my work on the fuselage for now. Yipee!!

It was a busy day, so I didn’t get too much done. I riveted the crotch strap attach brackets in place.

I also put the ends on the front elevator push tube. Talk about a tight fit. It took some hammering to get the things to seat in place. Hopefully that doesn’t cause problems down the road. I looked up the part number for the rod ends in the Spruce catalog and they’re supposed to be used for tubing that has a smaller wall thickness. No wonder they didn’t fit.

I had a very productive day. I deburred the remainder of the subpanel parts, except for the skin.

I next pulled out the crotch strap attach kit. Matthew was right. I’d eventually need to pull the control column stuff out again–like two days after I installed it. The attach kit has been sitting waiting for a long time, mainly because I knew it would be unpleasant. Leaning over the sides of the fuselage trying to drill with the angle drill lived up to my expectations. I basically clamped the aft half in place where the plans indicated and drilled the holes. After that I clamped the front half to the aft half with some 1/8″ spacers and drilled that. I drilled out the holes for the AN5 bolt next and then drilled the seat skin to the brackets. The passenger side turned out really good, but the pilot side has some marginal edge distances in the top of the bracket. I’m not exactly sure what happened, but I guess my measurement of 1/32″ back from the screw hole wasn’t precise enough. My suggestion would be to mark some center lines on the tops of the brackets and verify they line up (or are at least visible) through the seat skin holes before drilling the brackets to the seat ribs. And my biggest suggestion is to install these things much earlier, like when you’re assembling the center section. There’s no reason to wait.

The last thing I did for the day was to prime the last push tubes.