Dave’s RV-7A Building Log

Cleaned, etched, and primed the rear spar parts.

Fluted the rest of the main ribs (while watching TV).

Clecoed together, drilled, and deburred the rear spar components left and right. Cut out the hole in the doubler for the push rod. The top is after using the unibit and a file. Bottom is after sanding with the Dremel.

Countersunk the holes in one of the doublers as directed. You can see in the picture that the aileron bracket is going to get in the way of the left most line of rivets.

Pre-dimpled part of the rear spar top flange, where the doubler fork will interfere later. (I laid the doubler fork on there upside-down, but you get the idea.)

Finished up the prep for the rear spar so that the parts are all ready for priming.

Made a jig to help with wing rib fluting, and fluted some of the main ribs. The picture on the left shows the overall jig. On the right you can see how a lamp from above makes the string cast a shadow on the holes. Clamp in the rib, line up the string with the first and last hole, and then flute until the holes are all under the shadow. You’re done! It really does work great.

Finished deburring the tank ribs.

Straightened the flanges on all of the leading edge and tank ribs.

I just need to do some fluting, and then I can put some stuff together finally!!

Did the final deburring pass on the leading edge ribs. All that’s left is the tank ribs.

Straightened the flanges on the remaining main ribs.

Finally finished deburring all of the main wing ribs. Just some touch-up on the leading edge ribs left.

I built the flange straightening tool from 21 Years of the RVator. It only took a few minutes to put together. I was sceptical that it would work, but it does! The long flanges take two passes. I got half of the main ribs straightened in 45 minutes, while watching TV. Always nice to be able to work on the project in the living room.

Tapped the holes in the tie downs brackets. My tap set said the hole should be 5/16″, so I reamed out the hole first. Then I tapped down 1″. I happened to have a 3/8 X 1″ bolt, so I tested the threads. They work great. I’ve never used a tap before. It’s a very cool thing.

Spent the rest of the time on deburring wing ribs. Here’s a picture, just in case you don’t believe me. Don’t they look so deburred??

More deburring on the rear spar parts. I’m going to buy a small Scotch-brite wheel. That would really hasten the smoothing of the inside of the rear spar doubler. I’ve been looking around for one locally, but they just don’t exist. Time to place an order.

Worked on getting the rear spar ready for assembly. I trimmed the reinforcement pieces at the root per the instructions. Since I don’t have drawing 38 yet, I don’t have a full scale template. I was able to use the measurements to my satisfaction to make the cuts with the band saw and clean them up with the Scotch-brite wheel. I clecoed the mating parts together and made them exactly the same length.

I also smoothed and deburred some of the edges for the rest of the rear spar parts for left and right.

I was too wiped to do any critical thinking, so I just did some mind-numbing wing rib deburring. This is the final deburring pass. I’m using emory cloth to clean up the tabs and corners that I couldn’t get to with the power tools. I got through half of the main wing ribs. Another 2-3 hours should be the end of the rib deburring.

Back-drilled the front spar to the tie downs and spacers. It’s easy to clamp the tie downs in place, but the spacers were wiley. They aren’t centered perfectly, but certainly close enough.

Then I drilled for the plate nuts, using one as a template. The first one turned out not very good. Then I figured out the best approach is to keep a bolt in the nut plate to make sure it stays centered while drilling. Clamp one side, drill the other (left picture), then put a cleco in the drilled hole and drill the other side (middle picture). The last step was to countersink for the nut plate attach rivets. Those parts are now ready to be primed. I’ll wait until I have a few more parts ready and do a big batch all at once.

I used the Scotch-brite wheel to make sure the fronts of the leading edge and tank ribs are nice and smooth. Reviewing the Orndorff video, they said that was important.

I also worked a little more on the wing stand. I fabricated and attached the cross arms. I figured out that where I have the posts is not going to work. One post is going to block a one inch strip of the wing. That will make it impossible to drill and rivet one side of the inboard most rib. I’ll move one post over a bit.