VIDEO New Suspended Bellcrank Mount from RSM Distribution

[Mike Griffin]

Thought you all might like to know about this.  Anything to make your life a little easier.

Click on the link:

[Mike Griffin]

Why are the washers so big?

To eliminate as much wobble as possible and help keep the bellcrank in a level plane.

Mike

[Roy DeCamara]

Those large washers have no effect on "wobble" because they are not in contact with the sides of the bellcrank.  Certainly not as shown in your examples.

[Mike Griffin]

Those large washers have no effect on "wobble" because they are not in contact with the sides of the bellcrank.  Certainly not as shown in your examples.

Roy if you use a bellcrank that just has a 1/8 hole for the pivot post and where the washers are in direct contact with the bellcrank, it adds support to the bellcrank to reduce wobbling.  The mount was made to accommodate various bellcrank designs.  Such as this one

Mike      

[Roy DeCamara]

I know that.  You did not show such an example..........tsk tsk.

[Ted Fancher]

I think I might be a little to blame for the large "washers" on Eric's new mounting system.  When he first came out with the 4" CF bellcrank he sent me one to evaluate and my only concern with it was that it had excessive "wobble" when mounted solely with the more or less standard "T" shaped pivot bearing such as used in the 3" nylon BC that Mike utilized in the early part of the video.  

Such wobble, if excessive, can be a major contributor to pattern problems such as unstable level flight and inconsistent exits from corners.  This is because a BC "wobble" along the longitudinal axis of the airplane exerts inputs to the elevator (and flaps) and is of particular concern when the pressure in one direction is abruptly reversed as in exiting corners.  I had three different airplanes built with beautiful circular bellcranks that a friend had made but, unfortunately, used poorly matched metals for the bearing.  As the airplanes aged they became less and less precise in maneuvers due to wear and resultant "wobble" and all three (the Imitation, the Citation V [1986 Nats champ] and the original Trivial Pursuit) had to have the bellcranks replaced due to excessive wobble due to wear.

At the time Eric shared the new crank with me I suggested larger washers top and bottom to prevent the wobble that was unrestrained without them.  I'm very glad to see this new product that will do exactly.  Good work by Eric.  

Although I'd like to take credit for the big washer idea if Brett Buck ever crashes his ancient but still beautiful Infinite everyone will be able to see where the idea came from!

Ted

[Mike Griffin]

Thank you for the positive input Ted.

Mike

[eric rule]

When people like Ted Fancher, Brett Buck, Bob Hunt, Randy Smith and others like them talk I tend to listen. The simple truth of the matter is that they don't just toss out theories. What they say is inevitably backed up by real life proof that what they say works. Probably explains why they tend to get the top scores contest after contest and their models always seem to fly better than the rest.

[Fred Quedenfeld jr]

Nice But what is the cost
Fred Quedenfeld

[Mike Griffin]

When people like Ted Fancher, Brett Buck, Bob Hunt, Randy Smith and others like them talk I tend to listen. The simple truth of the matter is that they don't just toss out theories. What they say is inevitably backed up by real life proof that what they say works. Probably explains why they tend to get the top scores contest after contest and their models always seem to fly better than the rest.

X2  Great point Eric.

Mike

[Mike Griffin]

Nice But what is the cost
Fred Quedenfeld

Sent you a PM Fred.

Mike

[Bill Morell]

Nice But what is the cost
Fred Quedenfeld

How can you watch the video and not know what the price is?

[Balsa Butcher]

For the price go to the RSM web site and look under "New Products". It is very reasonable.