of the MMP Snow Skis is important for maximum performance.
Brief installation procedures:
Install main gear skis parallel to wing.
Nose gear ski should be slightly nose high.
Do not use a tail ski. It will likely catch on ice, and can rip your rudder off of your airplane. Possibly even the entire tail.
You must clean and dry all oils off of your axles before installing skis.
Ensure you have proper axles. And ensure that they are tight and cannot rotate under load.
Don't over tighten set screws. Don't remove screws from lock block once the screw tips have been deformed on the axles. Or, it may strip the aluminum lock block.
Carefully oversize axle holes to 1/4" if needed. A tight fit is necessary.
Detailed installation procedures:
MMP Snow Skis should always
be installed parallel to the wing! Especially in the Tail Dragger configuration. Due to the leaf spring
design, if they are installed with the tips nose high, the springs will influence the airframe into a nose-down
condition on takeoff and landing. It will also cause
unnecessary trim changes in the air! They are self centering skis, NOT free
floating bungee skis, and should NOT be installed nose high.
The only exception is the nose
gear ski on tricycle configurations. Due to the spring coil in
most nose gears, the nose landing gear wire tends to flex
rearward. When this happens the ski tends to rotate slightly
nose down, reducing flotation. So, a slight nose up installation of the
nose ski only, is desirable. When setting the nose gear skis up
on the bench. Simply prop up the front of the ski, very slightly, with something like a
pen or a piece of wood. It should not be tipped much, just a little
bit nose high.
A tail ski is not
recommended (or supplied) as it can easily grab snow and ice and
tear the rudder off of the plane, or worse. And that is a bad thing. The tail
wheel will provide ample steering, and the rear of the fuselage will
provide plenty of flotation that is necessary on the snow.
Your axles NEED to be
CLEAN, and DRY, when the skis are installed. The set screws are
relying on a tight, slop-free, friction fit, to hold the skis tightly
on the axles. Oil reduces friction. 'Nuff said. Any fuel and oil dripping, and soaking, on axles is something
that can undermine the skis otherwise premium performance! Remove all wheel and axle lubricants and contamination before installing skis!
Make very certain that your
AXLES ARE TIGHT! Use of (5/32") axles with a large
mounting stud, and nut, is highly recommended when using aluminum or
fiberglass landing gear. If the ski holds tight, but the axle spins,
you have undermined the design! Screws do not constitute proper axles. See
The set screws are 8-32 grade 8 hardware
on the newer skis, and 6-32 stainless steel on the older ones. Both of
the screw tips will deform slightly to the contour of the axle when tightened
onto the axles. This
helps them to grip the axle. Therefore, do not back the screws all the way
out into the aluminum threads, once they have been installed tightly onto an axle. Or, you can subsequently damage the
threads in the lock block. Don't over torque the set screws. if you do accidentally over-torque, and snap off a lock
block screw, these skis have been designed with enough aluminum material so
that the screw can be extracted, and if the threads are damaged in
doing so, they will accommodate an oversized set screw. They can also be drilled for a new screw, in a new location entirely. This is an intentional design feature. Repair-ability.
If your plane falls in a weight
range where you prefer using 1/4 inch axles, the MMP skis are
designed to accommodate
being carefully oversized to match the 1/4 inch axles. BE CAREFUL,
and make as close of a tolerance fit as possible. Sloppy
over-sizing of the axle holes is a perfect way to reduce the
tight friction fit required to hold the skis tightly on the axles!