Mark Napier made drill templates
to use for the control system belcranks. He sent me one and still has 3. Mark
and I can send one to you if you want to use them to build the bellcranks.
Here is what Mark wrote in January 2003:
| [...] A buddy made me up a template for drilling all
those bellcrank bearing holes. It uses a 1/4" tooling hole which
is the same hole you can then use for the hole cutter for the .86"
bearing clearance hole. The template is 1/8" steel and is dead-nuts
on. To make it, David need to stack up 4 in order to fit into his machine.
[...] The template works very nice. Drill a 1/4" inch hole to use as the center. Bolt on the template. Drill all the other holes with a #30 drill. Then use a 7/8" hole saw (white bi-metal thing from home depot) to cut out the center. It uses a 1/4" drill as a pilot. Cut from both sides to the center and then clean up with an air grinder. Perfect. I did Jim Huber's bellcranks. Here you want to make a master and be sure you drill them all exactly the same. Use the template and also use the other holes as tooling holes. Works great. The spacers are 3/16" aluminum. If you get the *steel* bellcranks then the spacing works perfectly for the F44-14 rod ends. For others YMMV. Bolt the rod ends in place before riveting the stack together or the holes won't line up. You would be surprised how much play there is until the rivets cinch up. |
See also: Jim Huber's bell bearing control system.
Check out the supplier's page for sources to obtain the bellcranks.