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RV-9A help from the 7A

F

Fedico94

Active Member
:eek:I am fitting the nose gear leg U-603-3 to the engine mount. I note that the end of the leg is not tapered and I can pass the gear leg through its socket and the lower collar and entire leg can pass through the mount. Is this the correct fit ? I used a micrometer on the end of the gear leg and note no taper (1.248 top and bottom of butt end) I do not note any significant play in the assembly.
My Concern is due to reports of failure of the AN5-20A bolt on VAF and the potential for the gear leg to shove up through the firewall.
I have already drilled the engine mount to the firewall.
 
Fedico,

Mine does not have a taper either.

Should be tight on the collars though.

Check that there is no wobble at the top
and bottom after you install the bolt. Nut
on the top.

Good luck,
 
Plenty strong

There should be no taper. The bolt alone should be strong enough to handle any forces required.

The tensile strength of an AN bolt is 125,000psi. Using Young's theorem (aka distortion energy theory or Von Mises theory), the shear strength is ~58% of that or 72,500psi. This is a 5/16 diameter bolt with a cross sectional area of .0767 sq in, so the single shear strength is 5560 lb. However, the bolt is in double shear, so the shear strength of the design is 11,121 lb.

That could pretty much handle hanging four Chevy Cavaliers from that one bolt.:eek:

Good enough for me.
:D

(note: I'm not actually sure of the value of 125,000psi for tensile yield strength. The table I found on the net didn't list it, so it could be ultimate, thus yield would be lower. Regardless, we're talking the difference between three or four Chevy Cavaliers here).
 
Last edited:
RV9A nose gear help

My information source for the bolt failure is from the RV Builders Hotline of 30 May 2009. Reference was to VAF RV8 Forum "RV-8 gear nuts and bolts" of 5-19-2009. I have gone to Van's for advice but have not had a reply.\
Thank you for the information at least I know what is considered a normal state in regards to the nose gear fit.
 
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