Trent's RV14 Build: 23-03 -> 04: Aileron pushrods

23-03: Long Aileron Pushrods

I began by cutting the long aluminium aileron pushrods to length using a cut off disc on the noisy die grinder. The plans have a template for placing the 6 x #30 holes in the ends, which get match drilled to the tube end pieces. However, the template in my plans was not to scale. So i laid out a new template which really stretched the grey matter for a metric native. The tubes were marked and drilled.

The template in the plans was a fair bit out.

Here you can see that it did not fit the tubes

My metric brain hurts

This is what we are trying to do...

The DIY template worked much better

Holes drilled.

Once the holes were drilled, i had to fit the tube end pieces and match drill these. However, the tube end pieces were very loose in the tubes. I wrapped them in a couple of wraps of scotch tape in order get them to fit a bit better (and i celco'd as i drilled). The tube ends will be primed along with the tubes, so these were marked with some dots from the centerpunch so they could be put back in the same places when ready to rivet. I will add primer when riveting in order to take up the extra space.

The tubes were cleaned on the outside and inside, then primed with EkoPrime (as they are aluminium). The tube ends were filled with BluTac to keep the paint out and sprayed, and the outside of the tubes were also sprayed. To do the insides, i put a balloon over the end and poured some primer inside. I let it drain out as i found it would not dry if left horizontal, and needed to be vertical to really drain out properly.

BluTac kept the paint out of the threads

A balloon on one end so prime the insides.

This is how i scuffed and cleaned the inside of the tubes.

To install the tube ends, i found the primer had built up a bit thick on the inside ends of the tubes and i could not get the tube ends in. So i cleaned the primer off the inside of the tubes, and painted some fresh wet primer inside and installed the tube ends wet.

A homemade 3D printed tool helped to screw in the rod ends.

23-04: Small Steel Aileron Pushrods

The small steel aileron pushrods were cut to length with a hacksaw and cleaned up with a file. To fit the ends, i found that they were too large to fit in the tubes. To files these down, i placed a couple of nuts on each threaded ends and chucked the part in the drill press. I used a file to reduce the diameter until they just fit, then sandpaper to finish them off.

To drill the cross holes for riveting the ends on, i made up a template in order to mark the holes at the correct length from the ends, and also to make sure they were opposite each other, and 90 degrees to the other pair of holes. I drilled the first holes to #40 based on the template locations.

The tubes were cut with a hacksaw and filed carefully to length (checking they were square on the ends)

Template used to mark the hole positions.

I used a vblock to hold the tubes for drilling.

Once the holes were drilled, I used a reamer to make sure the holes were properly aligned and they were perfect. The rod ends were placed in the tubes and the first hole was match drilled to #30, then clecod. I did this for all the holes in the rod ends, then removed and deburred everything. Each part was marked with a number so it ended up back in the same place.

Could not fit these on the drill press, so used a hand drill for the other holes.

All match drilled.

Since the pushrods were steel, i could not use my waterborne primer - this creates flash rust inside the tubes. Instead, i purchased some Norglass ShipShape boat epoxy. The tubes were cleaned inside with acetone, then the primer was poured into the tubes until the insides were covered. The rod ends were also painted and placed in the tubes wet. Rivets were put in the holes but not set - then everything was left to dry.

Nice paint coverage inside the tubes.

The rod ends were left like this for the paint to dry.

After the paint was dry, the rivets were set with a hand squeezer. I elected to use a normal -4 size cupped set on the manufactured head side, and for the shop side i used a -5 size cupped rivet set. This let the rivet sit in the middle of the set and prevented the rivet from tipping over (as it was so long). Plus, it looks better i reckon (and less likely to catch a rag on the rivet tails etc).

Setting the correct length for each rod end.

The plans give some lengths for each pushrod - but there are a couple of issues with this. One is that the measurements are given from the centre of each bolt hole at each end, and the other is the rod ends are clocked 90 degrees in relation to each other.

In order to accurately measure these, i set up a couple of wooden blocks on the bench, which had #12 holes (3/16") drilled for AN3 bolts. I was then able to measure accurately these blocks and clamp them to the bench. It was then an easy task of winding the rod end bearings all the way in, and progressively and evenly winding them out until they aligned with the bolt holes and a bolt could be slipped in place. I then nipped up the jam nuts (but didn't fully tighten them yet).