AXI Motor Mount - Ralph Snow - ralphsnow (at) alum.mit.edu

This is the mount I made for my AXI 2212/20 motor. I built the model with a light ply motor mount at the front of the fuselage, with four 4-40 blind nuts attached. I then discovered that the model was seriously tail-heavy. So I got a PVC pipe union about 1 5/8 O.D. at Home Depot and sawed it to 7/8 inch long. I cut two light ply discs, one with the same diameter as the union and one matching the I.D. of the union. I epoxied the discs together and then epoxied them to one end of the union. I drilled a hole in the center to clear the shaft of the motor and attached a tube made of rolled paper. I glued a balsa plug into the paper tube to close it off and epoxied some balsa pieces to the inside of the union to enclose the mounting screws and enable me to cut away part of the wall of the union for routing the motor wires. When completed I filled the mount with epoxy and small lead sinkers, about 2 ounces in weight. It turned out to be just enough to get the C.G. where it needed to be. If you have any questions please e-mail me.

AXI motors can be mounted in two ways. One way is to mount it behind a plywood bulkhead with the prop shaft protruding through a hole in the bulkhead. In this case the motor is completely enclosed within the fuselage. I am building a model right now which will have the motor mounted in this way.

     Since the Randy Randolph model that I built was originally powered with a glow engine sticking out in front of the fuselage I thought the best conversion would have the electric motor mounted in front of the fuselage. For that mounting arrangement I purchased the optional mounting kit which consists of a flat "x" shaped plate which is attached to the non-rotating part of the motor and a prop adapter which attaches to the rotating portion. With this arrangement the shaft which served as the prop shaft in the mounting scheme first described is no longer any use but is still there and must be accommodated.

Normally, this only requires a hole drilled in the center of the mounting bulkhead for the shaft to stick through. So, when I built my

PVC mount I drilled a hole through the two light ply disks that I described previously to accommodate the now non-functional shaft. In order to be able to fill the mount with epoxy/lead I had to make a "pocket" around the shaft to keep the epoxy from leaking out through the hole while it hardened. That was accomplished by gluing a rolled paper tube to the inside ply disk and plugging the tube with a balsa disk that would just clear the end of the shaft when the motor was mounted.