Nosewheel Breakout Force

[retasker]

I am installing my nosewheel (RV9A) and attempting to set the breakout force as specified in the construction manual.

It seems that to get to the 14 ft-lbs (22 lbs side force) I have to crank the nut down so the two belleville washers are totally compressed! Is this correct?

Second, the instructions say to temporarily safety the nut and move the fork back and forth to the stops. How are you supposed to safety the nut?? Is the fork leg supposed to be already drilled for a cotter pin? I have a reworked leg and it isn't.

Thanks for your advice!

Dick Tasker

[robertahegy]

You have to drill the cotter pin hole for the castle nut. I put the belleville washers so the outer edges touched when they were not compressed. They may seem fully flattened, but they shouldn't be, unless they have lost their resilience.

Roberta

[retasker]

I figured that a hole would have to be drilled, just was confused with the comment in the instructions (and not sure since the gear leg was shortened).

What you described is how the washers are used. While I would not say that are "totally" flattened, there is not more than 1/2 turn of the nut left. Just doesn't seem quite right. However, I doubt that they have lost their resilience just sitting on the bench.

I will proceed as is.

Thanks

Dick

[Geico266]

If the holes don't line up go to the next hole. It is better to have a higher break out force than lighter to fight wheel shimmy.

JMHO.

[mtclay]

What's the actual procedure for measuring the breakout force?

Where on the fork do you attach your line to your fish scale? I assume at the axle?

Then I assume you elevate the nosewheel slightly and make a level pull 90 degrees from the longitudinal axis?

Forgive these newbie questions. I'm not the builder -- I bought the aircraft and have not yet measured the breakout force.

[Geico266]

Originally Posted by mtclay

What's the actual procedure for measuring the breakout force?

Where on the fork do you attach your line to your fish scale? I assume at the axle?

Then I assume you elevate the nosewheel slightly and make a level pull 90 degrees from the longitudinal axis?

Forgive these newbie questions. I'm not the builder -- I bought the aircraft and have not yet measured the breakout force.

You have it right. At the axle. I sent them at 25-30 pounds, and keep the tire pressure up.

[mtclay]

You have it right. At the axle. I sent them at 25-30 pounds, and keep the tire pressure up.

Thanks Larry.