Miniplane-USA

        The PolyMounts came about while I was working on my never ending homebuilt PPG project. I had made a breakthrough of sorts in my design, and it came time to go down to Grainger's and pick up some rubber mounts. I never really like the rubber mounts we used. I thought they were too soft and flexed way too much. They also tended to sag after some time. I have had some sheer on me and witnessed several disastrous and expensive events caused by failed motor mounts over the years. I did some research and discovered they were actually made for sitting on the ground indoors. They were never intended for vertical mounting outdoor use.
        I casually started looking at the McMaster-Carr web page and came upon some parts that if welded together could act as a strong foundation for new motor mounts. I bought a few bags of these parts to see what I could come up with. Some time later I talked with my girlfriend's 20 year old son, Zak, a top professional downhill skateboard racer, gearhead and tinkerer. At 16 he had started making polyurethane skateboard bushings under venomskate.com and is now the largest producer of skateboard bushings in the US. I ran the idea by him, he said it sounded solid, and suggested we try making them with polyurethane instead of rubber. They would be way stronger and could be made in cool colors.
      After studying up on the properties of polyurethane, I found that is is much more versatile than rubber, handles temperatures from -85º to 200+º and the formula can be varied to make a large variety of durometers. I looked into this claim and found that race cars, performance vehicles and even high end modern hot rod use polyurethane in their suspensions. Zak then suggested I weld up some sets, make a mold and the company he worked with in Denver could pour several sets in different durometers for testing. We chose some nice colors to distinguish the various durometers. Zak managed to scrounge some ancient analog equipment from his grandfather, who ironically used these tools for testing on the original Viking Mars Probe. We rigged up the oscilloscope to measure dampening and vibration, and started the testing. Narrowing it down and eliminating the really soft and really hard sets we were left with a couple of compounds that showed a good compromises between idle and full throttle. After flying both of these sets I felt we had a winner! I was convinced, but what about other pilots? I had the company make a dozen sets in orange, blue and red, sent out eight sets to various pilots and respected industry pilots, and waited. Slowly the feedback started trickling in. Everyone loved them! They said the mounts cut down vibration and even helped with out-of-balance props...very strong, no sagging after a year. They all commented on the cool colors and shape. Even Alex Varv was complimentary after all the tough torture tests he put them through. I strongly feel this product is needed in our sport. I hope you do too. On with the Motley!
       
-- Fly safe, Robert Kittilä

 

INSTALLATION INSTRUCTIONS

When installing your new Poly M8/M6 Mounts, please use medium thread locker
on the bolts and leave them to cure overnight.  Tighten the bolts snugly, but do not over tighten.  If you use your own bolts of a different length, make sure they don't touch the set screw, as this will increase vibration and cause your mounts to fail.  Enjoy!