stunthanger.com
Building Tips and technical articles. => Building techniques => Topic started by: Gerald Arana on August 17, 2013, 08:17:56 PM
-
I recently purchased a Tom Morris bellcrank (system) for an ARF Nobler. I'm turning it into a "Brock" Nobler.
What I want to know is: Is the 1/8" phenolic BC enough of a bearing surface without any reinforcement on the pivot point?
Personally, I think I should epoxy a couple 1/8" dia. supports to the top and bottom of the bellcrank.
What do you think?
Thank you in advance, Jerry
-
If I understand the question correctly, I wouldn't feel good about only having it held down to one platform. I would run the screw or shaft through a top platform, through the crank and then through the bottom platform. No reason not to. And I usually double the rib that takes most of the force of line pull, or glue in a brace to distribute the load.
-
Did they forget to send the instructions on the mounting of the bell crank? In all the ones I have/had the were brass eyelets to space the bell crank between the top and bottom mounts for the bell crank rod. Leave enough on each end to put a groove in for a washer and wire wrapping to keep the rod in place. I used the J-B Weld on my Spitfire and the rod slipped out after several dozen flights. Never again as I also put ply plate over the end of the rods.
-
RknRusty, No I didn't mean the mount in the wing. Got that covered with a ply plate top & bottom. (1/8" rod)
Doc, I got this set up second hand. It has instructions but it doesn't mention bell crank instructions. I thought it should have brass eyelets (or something) to keep it centered.
Thanks for the input, Jerry
-
The thick phenolic bellcarnks I have used came with the pivot wire, brass eyelets all soldered in place.
Your "second hand" crank does seem like someone had taken it apart. If you don't have brass eyelets, a couple of 6/32 nuts, drilled out and soldered in place will do just fine.
Floyd
-
Great idea! Thanks Floyd. %^@
Jerry