%22Floatin%27 %22 bell crank

Stuka Stunt Main Forum · 10 of 10 known posts recovered

Bootlegger · Oct 05, 2006 04:08 PM

Guy's what is the easiest way ya'll have found to install a floatin or suspended bell crank ?? I am lookin' to install one between two (top & bottom) pieces of 1/8" plywood.
I have already installed the ply, and the b/c will be located between two ribs about 1/2" apart. As in a Cardinal profile wing.
I am needin' to shim the 'crank so that it will not float up or down...
As usual this is the best place to get this info...
T I A

Gil Causey

Ron King · Oct 05, 2006 05:03 PM

#1 source

I use the Tom Morris suspended bellcranks. Tom supplies a 1/8" drill rod for the pivot and you place a washer and a 1/8" wheel collar on the top and bottom to center the bellcrank.

Then it's up to you. Some guys just put them in and cover the top and bottom holes in the wing with small pieces of plywood to keep the rod from moving up or down. You can also add small pieces of fuel tubing to help keep the rod from slipping around.

I'm somewhat anal about this, so I use nylon spacers (from the hardware store) to lock the bellcrank on the inside. Then I cut the rod flush with the wing skin and use a small piece of 1/64" ply top and bottom to seal the hole.

Hope this helps,

Ron King

"The greatest attribute is tenacity. Do not be surprised when tenacity overcomes talent." - one of my college professors

ty marcucci · Oct 05, 2006 08:00 PM

#2 source

Also you do not want it to rock up and down at the tips, so keep it snug, but not tight.

LeagueCityRalph · Oct 05, 2006 08:09 PM

#3 source

> Guy's what is the easiest way ya'll have found to install
>a floatin or suspended bell crank ?? I am lookin' to install
>one between two (top & bottom) pieces of 1/8" plywood.
> I have already installed the ply, and the b/c will be
>located between two ribs about 1/2" apart. As in a Cardinal
>profile wing.
> I am needin' to shim the 'crank so that it will not float
>up or down...
> As usual this is the best place to get this info...
> T I A

If I'm reading this correctly, you've already installed both (top & bottom) plywood mounts. This will make B/C installation rather "twitchy"

You'll need to start the pivot rod through one side, slip a wheel collar or other spacer over the pivot and push the pivot in a bit further, slip the B/C into position and push the pivot, and then add the final collar/spacers/whatever, and push the pivot on through the other side. As I said - -"twitchy". Of course, you still need to tighten the set screws on the wheel collars (using Loctite), and add a bit of epoxy top and bottom to make sure nothing slips out.

I've done it that way twice on ARCs. Built from scratch, I always assemble all the components (including a pushrod stub) and install the whole assembly at once. Much simpler.

Ralph Wenzel

GLBahrman · Oct 05, 2006 08:51 PM

#4 source

LAST EDITED ON Oct-05-06 AT 08:53 PM (CST)

Tom Morris Bellcrank between ply. The bellcrank comes with wheel collars to isolate it, one above and one below.

Greg L. Bahrman

LNeumann · Oct 05, 2006 10:41 PM

#5 source

>Tom Morris Bellcrank between ply. The bellcrank comes with
>wheel collars to isolate it, one above and one below.

You can also use 1/8 inch eyelets and solder them on to the rod. SIG makes some nice ones with wide rims that work perfectly for this.

Leonard Neumann
Indianapolis, Indiana, USA

Warren · Oct 05, 2006 10:59 PM

vertical shims#6 source

> I am needin' to shim the 'crank so that it will not float
>up or down...
> As usual this is the best place to get this info...
> T I A

I'm a little paranoid about possible vertical movement of the bellcrank under pressure and vibration, so even after locking with wheel collars and CA, I put short lengths of 1/4" diameter wooden dowel to take up all of the vertical space (they too get CAed in place). Then plywood end caps are put on both ends of the shaft. That bellcrank is NOT going anywhere!!

[photo not recovered: 4525d248225309a1.jpg]

Also note that I did not glue in the upper bellcrank support until ALL of the BC assembly work and fitting was completed. That makes life a little simpler.

The fun part is drilling the hole lengthwise through the 1/4" diameter dowel, but I'm going to let you figure that one out on your own. The hole must be centered in the dowel now...no sloppy work....Windy is watching you !! <g>

Construction is a UHP kit of Ted Fancher's "Imitation".

Cheers.

Warren Wagner

Bob Reeves · Oct 06, 2006 04:22 AM

RE: vertical shims#8 source

>The fun part is drilling the hole lengthwise through the
>1/4" diameter dowel, but I'm going to let you figure that
>one out on your own. The hole must be centered in the dowel
>now...no sloppy work....Windy is watching you !!
>
>Cheers.
>
>Warren Wagner

Pretty easy with a lathe

Igor Burger · Oct 06, 2006 04:18 AM

#7 source

I prepare everything "outside" ... you can see all here:
http://www.rcmodely.sk/F2B/

Bootlegger · Oct 06, 2006 05:35 AM

#9 source

Guy's I sure do apprciate all the help. This site really has some helpful info and I thank Leonard for it this site...
Have a good day fellows.......

Gil Causey