Feet to mount on a butcher block platform

So just deny the the existence of a problem; therefore it won't be a problem for you, right?

 

Only if it's audible.

 

My tech's been to Japan and witnessed the vibration tests at the factories.

 

Ikea Aptilig bamboo cutting board, based on a thread I read here, four of these things,https://www.amazon.com/Diversitech-...ads+for+washing+machine&qid=1634482663&sr=8-8
levelled with Blu-Tack. Works fine as far as I can tell-no footfall from a suspended wooden floor.

 

What I use and work great! Low priced too.

As someone mentioned with some other feet, put a piece of paper under the bottom of the feet as it will stain wood.

 

No. But thanks for the idea.
I'm trying to use metal to metal to convey midrange distortion (vibration held within the body of the turntable during playing).

I want the metal shafts and metal washers to carry the vibration OUT of the turntable and down the hard rubber/plastic feet to the platform where it can be absorbed.
Rubber bushings won't carry that vibration as well---it will absorb it and possibly make the tone mushier.

The idea is to use hard solid contact to drain the sound into a hard solid wood platform base to add mass to the body.
Then UNDER the platform is where the gooey absorbent stuff goes to "float" the table and de-couple it from the shelf and floor.

That's the mechanical theory behind what I have done.
And the clarity and deeper bass I am getting is proof that tightening up this turntable is moving it in the right direction!
Plus those washer allow me a spiffy way to shim and adjust the height of the table to level it perfectly.
I have two extra shim (washers) on the rear foot.

The metal washers also have another benefit that they have collapsed the footer shafts and made them "solid" instead of pistonic.
Fluance designed it so the table could move up and down on those footer shafts on little springs (!) to kill vibration.
It is a cheap noisy undependable way to accomplish this task and the movement is very cheesy.
Now the shafts of the feet don't move up and down any more because the washers have collapsed their springs---yay!

Frankly my next step isn't replacing the washers---it would be experimenting with solid metal pointed spikes if I could ever find some with that fine a thread to try out I would.
Meanwhile I live with what came from the factory and that is hard rubber/plastic feet on solid metal shafts for now. And it seems to be working (the important part!).

I have all the isolation I need from the silicone pads UNDER the platform.
I don't NEED those shafts to move noisily up and down the way the factory designed them.
The metal washers have fixed that problem quite solidly and quite completely.
Rubber might not lock everything tight enough is what I am saying.
Metal is TIGHT.

You guys seem to think my home made washer shims are ugly---which is TRUE I suppose.
I COULD do something as simple as align the washers tighter to make them more of a tidy look and make them look "prettier."
But "pretty" is ONLY fine as long as it doesn't cause problems getting there.

I go for form over function but if it works don't touch it.
Right now everything is working.
I ain't TOUCHING nuttin'!
Those washers can sit there proud and ugly---but WORKING!

CUSTOM DESIGN BY DOCTOR FINE , ha ha...

 

I'm no expert on vibration control, but I'll convey my limited understanding.

Assume a vibrating body VB bolted to the floor.
The floor is a much larger mass than the VB is trying to move, transfer energy. It's can't, so it continues to vibrate. The rigid connection absorbing some of the energy. But not much since little deflection.

Now put the VB on cork pads for example.
The cork 'gives' more and more energy is dissipated distorting the cork (and heating it up a bit). The cork is also preloaded to a point where it is tensioned and vibrates easier, like a stretched string.

I would like someone with more education/experience to chime in.

We always put generators, compressors, pumps, etc. on isolators, to reduce floor loading and reduce motion of the machine.
If transferring the vibration to other areas we put the machine on an inertial isolation block, basically a block of concrete isolated from the rest of the floor. That provides 2 way isolation.
Also provides dampening.

Energy is like electricity or water, it wants to equalize, dissipate, follow the path of least resistance to equilibrium.


The inertia block is similar to a TT with isolation feet on a butcher block on iso pods.

 

I own several extra heavy wood bodied electric guitars.
That extra mass they have compared to lighter guitars will develop a bigger deeper tone.

I'm using the same mechanical strategy to beef up the bass with my lightweight Fluance with its wood body.
By coupling its own low weight body to a heavier wood platform I am increasing the apparent beefiness of the entire affair.
Just like using a heavier piece of wood to make a guitar vibrate with more authority.

I have studied the designs of better, more expensive turntables and the one thing a lot have in common is extra body mass to increase tonal depth and improve bass.
Then they use some form of isolation to decouple the table from floor vibration and airbourne noise.

I'm just stealing their ideas on the cheap...

 

Vibration isolation is both from internal and external. The standard mount you show is intended to isolate the surrounding environment from the vibration created by the generator.

However, the same concept can be used to isolate the generator/table from the surrounding environment. Ships will mount components on resilient mounts to isolate the component from the Ship's natural frequency generated by the propeller. But, at the same time, the same res-mount can isolate the Ship' structure from the vibration generated by rotating equipment.

All of these resilient mounts are modeled as a spring and they have a resonance just like an electrical-filter and while a resistor can damp the resonance peak it also changes the slope of the attenuation after the cut-off frequency and same occurs with res-mounts that are damped.

But what @Doctor Fine is doing is stiffening the connection to the res-mount (the foot). If the connection is soft then you end up with essentially two springs - the weak connection between the table and the foot is one spring, the foot is another spring. In this arrangement you can get some very odd behavior because they can be essentially bouncing/vibrating (very slowly) in & out of phase which means sometimes at some frequencies it may work great but at other times not - it can have two different resonant frequencies - 12_vibration.PDF (psu.edu). Given the weight, one could argue that there will be no difference between a stiff nylon and steel, but its working, and there may be a good explanation.

Is it draining vibration; its conservation of energy; the table has some natural frequency caused at least by the rotation of the platter - albeit very low - so any vibration travels through the plinth through the now solid connection to the feet where vibration is converted to heat. However, adding a stiff material with a high damping factor that will not act as spring can act to damp/drain the table internal vibration while the feet isolate the table from external vibration. So if we follow this thought a stack of copper washers could provide 10X the damping of steel. I am trying to find the damping factor for nylon.

 

like a spring loaded at both ends.

The concept of electrical transients is similar mathematically.
The reflected wave can by in phase or out of phase with the incident. Cancel or augment.

With some systems easier to select isolation because the disturbance of the load is much greater than the 'platform' it is resting on. In addition the frequency fundamental of the driver is known, in the case of a pump or smaller generator ~ 30 Hz.

Many isolators are spring loaded and adjustable. Measure, then adjust, repeat.

https://kineticsnoise.com/hvac/pdf/sminstall.pdf

 

One item often missed is the mechanical vibration caused by the motor - AC Induction Motor - Electrical Vibration Frequencies (vibrationschool.com). So the spring resonant (cut-off) frequency is selected low enough to (like a line reactor) to filter out (absorb) all high Hz vibrations.

 

Also depends on the driven load.
The motor reverses torque pulse 2 x per cycle.
But if a diesel driven generator it may contribute different freqs based on cylinders, speed, etc.

Same for the driven load: positive displacement vs. centrifugal. Reciprocating, etc.
If built right and aligned properly pretty small.
If not, shake itself apart.

The mfg. typically sends the mounts and tells the installer what vibration is acceptable when aligning.

 

Ideally, wall mounted platform is the best solution possible, but not everyone wants to drill anchors in their wall or see audio cables hanging down.