Monthly Archives: March 2016

It took quite a few days to grind through the top skin riveting of the first wing, which for random reasons is the right wing. There’s a lot of opinions out there about the “best” way to rivet top wing skins. Some claim back riveting is the best method by far, others claim the crooked back riveting tools are impossible to use and results with conventional riveting/bucking are good. I decided to give back riveting a go and it worked out well, but it requires two of us and after an hour of pressing that large/heavy back rivet bar onto the skins we’re ready for a break. As a result the work was spread out across a number of days, with just 2 – 3 one hour sessions each day. It’s hard to take meaningful photos due to light reflections playing tricks, but I tried my best.

After completion I went back and inspected every rivet. There were a couple already marked – I tend to leave any problem rivets to the end. The final tally was four drill outs, and seven rivets that required a few more taps because they were under-set.

I’m going to go ahead and fit the gap fairings to the right wing, because they’re easy to do and we’re going to take a break for a few days before starting on the top skin of the left wing.

Big push today to rivet the right wing front and rear spars, and cleco on the top skins. The right wing is now at the same point in construction as the left wing – ready to rivet the top skins on.

Now I need to get “Rosie” involved…

After all the preparation work, yesterday and today I finally started riveting the wings, beginning with the left wing front and rear spar to ribs riveting. I was able to squeeze every rivet on the front spar using the “monster yoke”. For the rear spar – which took a lot longer – I used a standard 4 inch yoke with various die arrangements, except for the three rivets on the inside flange of the Aileron bracket, which I drove using a double offset rivet set.

After riveting was complete, I cleco’d on the top stiffeners, inboard wing walk doublers and both wing skins. Everything matched up perfectly, which seems to have vindicated (so far) my decision to do all of the wing component preparation and priming before riveting.

I put the left wing assembly back on the wing rack, and will now repeat the dose to bring the right wing up to the same level.

Some time ago I wondered why it was not possible to get a larger longeron yoke for the pneumatic squeezer. Out of interest I sketched up what would be required to do the front flange of the wing ribs (there are no doubt many other uses), and had a real live aerospace engineer (my son) draw it up and do a stress analysis. It all looked OK so I had one fabricated on what turned out to be a very slow schedule. The yoke is made from 4140 steel and hardened with a heat treatment, just like the ones you buy. There was a bit of concern about the heat treatment process distorting the part out of alignment, but that turned out to be a non issue. I picked it up today and after a bit of fine tuning all the pieces fitted together as they should.

The yoke is sized to be able to reach over the largest part of the RV-10 spar down into the middle rivet of any rib. There are extension pieces that can be plugged in after the yoke is in position, as shown in the pictures. I tried it out today on a couple of rivets, and after a bit of adjustment it worked really well. The displacement (the amount that the yoke “stretches” under pressure) is quite a bit more than the conventional smaller yokes, and that takes a bit of getting used to. I set just a few rivets, and verified that they can be repeat-ably set to perfection.

Tomorrow I’ll go ahead and rivet all the ribs, as well as the tie-down brackets etc. to the wing spars.