Fri Jul 3 2009

Riveting pushrods

Today my dad and I worked on getting the end cap of this pushrod pulled out a bit. We figured we could use a bolt, nut, and some washers in conjunction with a piece of leftover tubing from the stock I cut these pushrods from to pull the end cap out. After some searching, I found the scrap piece from this pushrod. Problem is it's not long enough.

I gave my buddy, Brent Owens, a call to see if he had a longer leftover piece. His wing kit is the same as mine, but his fuselage is narrower, so I figured he might have a longer piece of scrap. Indeed he did! We drove out to his place and picked up this five inch long piece. I cut a section off that was about two inches long. Thanks, Brent!

Ok, here's the arrangement mocked up on a yet to be installed end cap. The bolt will be slid down the tube so it sticks out through the threaded hole in the end cap. We'll slide the two inch section of tube over the end cap and use the hose clamp to keep it concentric with the pushrod tube, then use the washers and a nut to pull the end cap out.

A picture is worth a thousand words, so here's the arrangement. Note the blue tape under the hose clamp to prevent getting the primer scratched up.

I had ground two flats on either side of the last 1/4 inch of the threaded end of the bolt so we could keep the bolt from spinning. This arrangement worked great and in just a few minutes we had the end cap pulled out to the correct position.

The bolt and nut trick worked so well for pulling the first end cap out a bit, that we decided to use it to press the remaining end caps in. All we did was clamp a couple pieces of oak down to the workbench, then used the bolt, nut, and washers to press the end cap in. We also used a bit of Boelube on the interface and a hair dryer to warm up the pushrod tube. We're not sure if the Boelube really made much difference, but the hair dryer was a huge help. Heating up the tube a bit allowed the end cap to actually slide into position rather than a stick-slip kind of motion.

Here's the first pushrod completed.

After a couple hours, we had all three completed. They came out pretty well, imo.

Last task for the day was to rivet these six rivets along each side of the fuselage that will get hidden by the upper fuselage skins. We also spent some time looking for the rivet gun. We had it downstairs earlier today, but at this point it seems to have disappeared into a black hole. Hopefully it'll turn up tomorrow.