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Sonex control play

PostPosted: Wed Jan 11, 2017 8:25 am
by lstinthot
I am assembling the aileron bell crank and elevator idler that use the bronze bushings. How well does this arrangement hold up? The bushings are not very serviceable without drilling out the whole assembly. Has anyone experienced play in their controls? Anyone use the bell crank bearing aircraftspruce sells? Looks like it would be a modification to the assemblies but it would make it serviceable and have ball bearings vice slip fit. Kind of against keep it simple philosophy but might be worth it if the current design experiences slop.

Mike

Re: Sonex control play

PostPosted: Wed Jan 11, 2017 11:31 am
by kmacht
I think you are overthinking this. It will be thousands of hours of use before you see wear on those bushings. They have very little relative load on them compared to their surface area and dont' see a whole lot of actual movement during a typical flight. In a typical turn the ailerons only move a 1/2" at most. Same for the elevator other than on takeoff or landing. Similar bushings are used in motors with much higher loads spinning thousands of RPM. The power steering pump for my 1963 ford tractor uses bronze bushings and still hasn't worn to the point where there is radial slop in the shaft. If it bothers you that much then when they do start to wear out you could always just go get a custom bolt machined a few thousanths thicker on the shank to take up the play. I'm of the opinion that if it isn't broke, don't go looking for a solution to fix it.

Keith
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