Low friction Free spinning two axis Gimbal Mount

Are you adverse to making your own? There are glass bearings aplenty. Got any details you can share?

How about an old aircraft ADI? They are sometimes called the ball or artificial horizon.

You can buy those on eBay, but there probably some steel in the bearings.

I would try a clockmaker/repairer or a marine supplier. Both Chronometers and ship's
magnetic compasses are gimbal mounted.

There may be something in an ex military surplus store

Also Astronomers models and some globes. Marine compasses can also be fluid mounted which might be another option for you if you only require two axis. Go to some markets, their are Indian (from India) people that make and sell what you require. a Jeweller or Clockmaker could give you jewelled bearings.

Hi,

there are two more possibilities if you can live with limited freedom of the gimbal mount:

a.: an air-bearing made from a hemispherical stator and a spherical rotor.

open halve of the hemisperical stator vertical up,

spherical rotor with a small diameter shaft protruding from the sphere, so that the rotor can be used with tilts up to 75°,

airbearing supplied with compressed air and a small nozzle at the center, the nozzle

can be exchanged to a porous restrictor or to a partial grooving of the stator or

rotor.

Difficult to build but very good in very low friction.

b.: second possibiliy is a flexure hinge, long time ago made bey Bendix then Teldix

now Lucas. We made ours much more precise (monolithic) by wire edm from a

solid piece of high quality metal.

The gimbal of this monolithic two axis flexure hinge is moving in a complicated

manner at rotation of the hinge about its axis of symmetry. This movement has

components that act as a negative flexure. So there is a speed where the positive

stiffness of the flexures is canceled by this inertia-induced negative flexure.

These hinges are used in a gyro (named dry tuned gyro) for inertial navigation and

gave a major breakthrough in the 70ies.

In the foto you see the two hinges of one axis (the rear one only shadowlike) the

two hinges of the second axis are not seen, the second axis is perpendicular to the

first axis and to the axis of symmetry.

You can glue from thin flexures and rigid parts a first approach.

RHABE

You may want to have better quality than this cup holder, perhaps if you have some design and machining capability you may be able to build one using model aircraft parts like clevis and hinge tape or use more industrial plastic components bearings and rod ends.

If it is just a quick test jig you need, using ABS or PVC tube form your hardware store and some pins should let you build one easily.

A Dead Weight Tester may be used if you have the right type.

No, its NOT obvious that it must be non-metallic! I does sound like it needs to be non-magnetic, but unless your magnets are moving rapidly, in which case they might generate excessive eddy currents, there are plenty of non-magnetic alloys available.

Since you mention low firction, bronze come to mind...

Size matters....

If you are looking for a small size mount you can make your own by nesting one slice of PVC pipe inside another and drilling for axle mounts. Bronze bushings for bearings are a good non-magnetic choice for a DIY. Which just leaves the pins. glass rods would be a pretty good choice there. A press fit sized hole for the mount and drill out the bearing side for the bushing. Good luck on with you searching otherwise.

Thank all of you for taking the time to reply to my question. It was generous of you to share your ideas.

Thank You.

Gavilan