Kit Aircraft Modifications

The other day I was hanging around www.vansairforce.net in the forums and I saw an interesting modification to the spacer holding the fiberglass wheel fairing on the outboard side of the main wheels. The original spacer, which is made from a threaded hexagonal extrusion has had a small number of attachment bolt failures thus far due to vibration. A couple of fellows from Texas have come up with a replacement that looks much stronger. Their names are Russ Davies and Dr. Linnard Griffin.

The picture below shows the old spacer sitting above the new beefier one. They both attach to the wheel nut in the same way but the greater amount of surface area that the new design places against the nut reduces the amount of stress on the bolt.

Here is a photo of the new spacer mounted on the airplane. The slots that are cut in the center of the spacer are there so a wrench can hold the unit while the bolt going into it from inside the nut is torqued.

All in all, I think that this is a great fix for the problem. It adds a little weight close to the CG which might be a problem for people who want the leanest machine possible but I would sacrifice a few ounces in exchange for the piece of mind knowing that my wheel fairings are secure and not prone to failure due to vibration.

Dave

A while ago I came up with a cool little modification that allowed for a better mounting of the Whelen taillight/strobe on my RV-10.

The problem that I heard others were having with the design of the lower rudder fairing was that it was difficult to get the 2 nuts that anchor the aluminum retainer ring epoxied in place. Mostly, this was due to the very cramped area within which you have to work.

I thought long and hard thinking that there had to be a better way to mount this thing. It dawned on me one day that it would be better for servicing the light if it were easy to remove from the plane altogether. The epoxy job tends to make the installation somewhat more permanent.

I got out a piece of 1/4″ aluminum and drilled a hole that was a little bigger than the outer diameter of the Whelen light housing. I transferred the outer retaining ring dimensions to the aluminum and started cutting it out.

I then located six holes around this ring of sorts that were away from the holes that hold on the retaining ring. I drilled these out to 1/8″ and countersank them till there was less than 1/8″ thickness remaining. The diameter of the counter bore was the same as the O.D. of a CS-4 pulled rivet.

I located the retaining ring’s mounting holes on the aluminum, drilled and tapped the holes to accept the machine thread mounting screws. From there I took the unit and cleaned it up and primed it. I placed the unit on the lower rudder fiberglass fairing and centered it in the location I wanted it and drilled out the six 1/8″ holes into the fiberglass and clecoed it on.

I then carefully removed the fiberglass in the center hole out to where it met the aluminum and trial fitted the whole assembly. I then blind riveted the ring to the fairing and installed the light assembly to make sure that everything fit as planned.

This modification worked to solve a couple of problems. First, it made the installation a much easier affair where you don’t have to work with epoxy and in a very tight area. Secondly, it makes the servicing of the light a breeze later on.

I will be making this adapter ring available for purchase in the near future. It is the perfect example of the type of modifications that I want to highlight on this blog.

Dave