Kenyon Gyro Mounting Issues
The Kenyon factory has warned of some dangers in modification of their gyro bodies,
not the mounting plates. Each gyro body is both anodized and epoxy coated to prevent
Helium leakage. Any drilling and/or tapping of larger holes in the body casting
can cause leakage and slowing of the gyro to 1/2 speed. Also be especially careful
to not drill any deeper than the original tapped holes. Find the right length
screws to attach a modified mounting plate. Do not tap larger or deeper screw
holes in the gyro body. The modifications below do not need any modification to
the gyro body itself only the mounting plates.
For prototyping your first gyro rigs
you can use good quality 1/2" or 3/4" plywood, 1/4"-20 or 3/8"-16
TEE nuts, coupling nuts, threaded rod and flat head screws. Once you get a rig
that you like, you can go to anodized aluminum plate or black wrinkle paint
for a more "professional look". When laying out the camera and gyros
for balance, do it on a small piece of plywood resting on a dowel or broom handle
to find the CG of a gyros/ camera combination. Check CG at 90 degrees for the
first test. If a rig is hung from above and the CG ends up in the middle of
a camera, consider the "trapeze" solution to raise the CG into the
body of the camera. Configure the camera and gyros as close as possible to each
other for the best stabilization.
The factory supplied mounting plate
is fine for attaching directly to a 1/4"-20 screw of a camera, but limited
for other applications. It is slow to attach the mounting plate and the KS-6
and KS-8 adapters are offset from the CG of the stabilizer. You can drill and
tap the center of the 4 screws of the KS-6 and KS-8 adapters, but threads are
only 1/4" deep and a bit risky because the engaging screw would have to
thread all the way (1/4" deep) to be perfectly safe. Kenyon does not recommend
drilling into the aluminum casting of the gyro.
The Kenyon supplied mounting systems
can be modified for easier attachment to devices other than a camera tripod
mounting thread. For the KS-4, I removed the supplied mounting bracket and tapped
it out to 5/16"-18. (It will still work as supplied with the 1/4"
screw back in position.) Remove the mounting plate and tap it in a drill press
and vice so the new 5/16"thread is straight. Now you can mount it on plates
and mill or file slots to allow side to side dynamically balancing about the
camera system's CG. If the mounting plate allows, placing a large hole and washer
on the other side of the plate will allow both front to back and side-to-side
Because the supplied mounting plate
on the KS-6 and KS-8 is only 1/4 " thick, I made thicker plates tapped
3/8"-16 using the Kenyon plate for a template. Watch the screw hole depth.
Get enough threads into the gyro body, BUT not too much to "bottom"
out. Use the Kenyon screws and plates for depth reference.
Bogan / Manfrotto makes a great little
Quick Change Rect. Plate Adapter # 3299 for about $30.00. Extra shoes are also
cheap. There are various ways to use them. The locking mechanism is secure and
almost fool proof. Using one either on the camera or gyro makes assembly and
aligning the gyro with the lens axis easier.
I removed the weaker 1/4"20
to 3/8"-16 insert and attached the Bogan adapter base with a 3/8"
screw from the bottom or a 1/4" flat head screw from inside the adapter.
You have to countersink the head of the 1/4" screw from the top of the
The simplest approach is to attach
the gyro to the adapter base and attach the shoe to your camera. It spaces the
camera and gyro over 3/4" apart. This way you can turn the gyro 90 or 180
Another more complicated method required
a milling machine and more work, but reduces the weight, lowers the profile
and can allow side-to-side and front-to-back adjustments. You attach the adapter
base to the gyro and the shoe to the camera or camera support plate. Remove
the 1/4"-20 to 3/8"-16 adapter and mill out a hole in the bottom of
the adapter base to fit the gyro with the factory mounting plate removed. Less
should be removed for the KS-4 than the KS-6 and KS-8 where you can go as deep
as the existing flats in the bottom of the Bogan adapter. Now use the Kenyon
factory plate to line up holes in the Bogan adapter. Clamp together and drill
with a # 29 drill. You will need longer #4-40 screws for the KS-4 and # 6-32
screws for the KS-6 and KS-8 to attach the Bogan Adapter to the Kenyon Gyro.
Make sure you get enough thread into the base but not bottom out. Study and
measure this carefully before milling.
The camera dovetail plate can now
be attached directly or the 1/4" screw removed and replaced with a 1/4",
5/16" or 3/8" flat head screw. If the attaching screw goes through
a larger hole to a larger threaded washer, you have the X-Y adjustment that
once adjusted for a certain camera. The camera plate can remain and not need
adjustment if not disturbed. The X-Y adjustment is for dynamic CG adjustment
of the camera system before powering the gyros.
Do not cut a hole in the mounting
plate until you test for the CG. Attach the gyro with a small hole and then
enlarge it in the direction that you might need CG adjustment in.
WARNING: The camera must be securely
attached to the gyro or a support plate. If you attach the camera to a surface
that has no support near the tripod attaching screw, tightening the mounting
screw can dish the camera's mounting plate and make the camera loose when mounted
on a flat surface. The tripod mounting plates on the bottom of all cameras are
intentionally made weak as a breakaway feature to prevent non-repairable damage
to the body of the camera. The screws are weak to break off under strain. If
you lift a heavy rig by the camera, you are putting too much strain on the mounting
plate. Remove the camera when moving the whole unit and attach it after mounting
the camera to a rig.
If your tripod mounting plate is
dished out toward the bottom of the camera, carefully remove it with a good
fitting screw driver and press it back into shape between two pieces of plastic
in a vice. Carefully replace the screws with the same tension as you removed
them. If the camera rocks, you can space up the sides of the camera with tape
near the base plate. If the camera rocks when attached you will have unstable
A handy material to provide friction
on tripod tops, camera bottoms, etc. is 3M Stair Tread with adhesive backing
available in many hardware stores.
© Copyright 1999-2004 Ron Dexter.
All Rights Reserved.