Re: TriQ Nose leg query

Jay Scheevel


The nose gear plate is bolted against the firewall, and the bolts are
tightened to increase the friction between the plate and the firewall. This
allows the plate to transfer and spread its upward load to a large area of
the firewall. This is a shear load, but the load is not on the bolts, the
load is transferred by high frictional shear between the plate and the
firewall (provided the bolts are tight).

Think of a tire on the road. The tire is pushing the car forward, yet the
tire/road "footprint" is perpendicular to this push. The weight of the car
provides the force (pressure) on the tire/road. Friction is the resistance
to slip and is proportional to the pressure and contact area perpendicular
to the road. In the case of the tire, the pressure is equal to the tire
pressure and the load it can maintain is as follows:

(tire pressure) X (surface area in contact with the road) X (coefficient of

This equation determines the total force that can be applied before the tire

The reason that the plate on the nose gear is so large is in order to
provide a large surface area for the application of shear load to the
firewall. The purpose of the bolts is to provide the force normal to the
plate, making the friction large enough to prevent any slip. You have
increased this effect by gluing the plate in place. That plate will not
slip. You will break the fork or gear leg before it will slip.

The gear leg is a different story. It is a spring and a spring needs to flex
in order to absorb load. If you rigidly affix the gear leg to the canard it
will still flex and will crack the material you use to attach it or more
likely just delaminate the glass from the Styrofoam underneath, where you
will never notice it. Either way, it does no good. I suggest leaving a small
gap between the leg and the canard and covering with a fairing if you
desire. My 2 cents.


Jay Scheevel - Tri-Q, still building

Join { to automatically receive all group messages.