"Dancing" machinery - how to make them stay put?

Gyroscopic precession requires that the gyro's rotational axis be displaced. If the buffer is just sitting there spinning, it's not precessing. If the shaft is tilted while spinning, and tries to twist

Dan

One way when bolting it down is to have two metal plates (per bolt or leg spot) and between them is a sheet of neoprene to absorb movement.

A set like that came with my large standup air tank/compressor.

Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder

carl mciver wrote:

Don't forget the sheet under the foot and the smaller 'washer' between layers under the bolt head. Don't want the bolt head to be a hard surface connection and defeat it all.

Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder

william_b_noble wrote:

Dan, Help me out here please. A certain gyroscope has a rod concentric to the axis of the wheel that extends away from the wheel a couple inches. The end of this rod runs in a bearing and is held captive by a couple retaining rings. This bearing fits in a housing that pivots on the end of another rod. This rod is perpendicular to the axis of the gyroscope wheel. The gyroscope is spun up with the rod end placed in the bearing and the rod (and hence the gyroscope wheel axis) horizontal. This pretty much mimics the grinder setup. The grinder is a motor with a shaft extending out about 4 inches. At the end of the shaft is a wheel about 8 inches in diameter. The wheel is balanced so there is little vibration. When the wheel is spinning the motor and wheel combination turn slowly around the axis of the pedestal. If the gyroscope is spun up it will also turn slowly around the vertical axis, won't it? If this isn't precession can you tell me what it is? If I'm wrong about something I want to know so my error can be corrected. Thank You, Eric R Snow

I took a look in my Mcmaster catalog. There must the hundreds of different sheet rubber formulations and thickenesses.

Any clue whether to go thick or thin and how soft?

I'm th>My buffers, grinders, brushes like to dance on my concrete garage

We used to put "isosorb" or something like that under the vacuum pumps around the lab. Crossed neoprene grids, you could stack a few layers for extra absorption, and put a hunk of steel on the top to keep the machine foot from punching down through. Could also get pre-made foot pads, but they cost more, and we were always on a tight budget. One figured out the per-foot loading and put in pads of an appropriate are to get the loading range suggested by the pad maker.

McMaster has similar, but not the same, material under "Vibration Damping Pads" (Pg 1224-5)

"Wonder Rib" pads from MSC (pg 1655) seem to be more similar to the ones I used. I have no idea if they are better or worse than other styles, simply that those are the style I have used.

There was supposed to be some advantage from the shape in terms of decoupling the vibration, but I don't know that it was anything more than sales hype.

At Princess Auto the other day I saw what looked to be clear silicone gell pads 1/4" thick with 3/4" dia buttons 1/2" thick in about a 4" square. I bet these would stop the dance but doubt they would support much weight. Gerry :-)} London, Canada