DIY Turntable project


I have recently started creating a turntable from the ground up I will be creating a blog with an extensive writeup of exactly what I did and more Importantly - why. 

Things purchased:

Tonearm/Cartridge

Cables

Protractor

Platter Mat

Motor / motor driver / motor belt

Isolation feet

Things I will be creating from scratch:

Bearing for platter

Platter

Plinth

Platter: The platter I have decided to go with is a 13" diameter 4" thick disc of solid Aluminum (54lbs). I chose aluminum over other metals due to cost. I decided to not go with acrylic due to the bearing setup I am using.

Platter bearing: completely custom ferrofluid double pocket bearings for the axial load and a Clearaudio CMB surrounded by sorbothane for radial loads. This means the platter will effectively have no physical contact to transmit vibrations through as ferrofluid pocket bearings actually use a rigid cylinder of air held in place by ferrofluid rings held in place by the magnetic flux of an axially magnetized ring magnet. this will reduce wobble of the platter to sub 0.01mm tolerances while still having the vibration mitigation of a magnetic bearing. 

Motor: Am in talks with 3 motor manufacturers, Will likely be going with a Kollmorgen 3430-A10 stepper motor (part of its PMX line). This motor will deliver around 800 oz-in or a little over 4.16 ft-lb.

Motor driver: likely a Kollmorgen P6000 

Motor belt: probably REGA - EBLT Advanced Drive Belt

Tonearm: Linn Akito Tonearm

Cartridge: Whatever I have laying around, probably a AT231LP for now.

Isolation Feet: Probably sorbothane feet.

Plinth: Will be isolated from the platter to reduce harmonic coupling and various issues. Will likely be made of rose quartz for wow factor.

Questions for the forum:

What have I overlooked? 

How can I reduce motor noise?

What do you want to know about the bearing? I spent nearly a month designing it.

thenightshade

See that you just joined today, so welcome and  good luck on your planned  project. Don't have much to ad but am sure that the people in the know here on Agon will chime in as you post your progress and I plan to be a fly on the wall. Enjoy the music

@thenightshade 

Welcome to the forum! Regarding motor noise, I found this video quite interesting

 

Very cool project!

I completed my turntable around 7 years ago & have been tweaking it since. My platter is also 4" solid aluminum but 12" dia. Plinth is from the same bar stock & 2" thick. The flywheel was made from 3.5" aluminum bar stock. The motor housing is also aluminum & holds a Hurst 300 RPM AC synchronous motor. The tonearm pedestal (aluminum & Corian) is adjustable. Everything is powder coated red &/or black. The platter is topped with 1/4 Delrin that is solidly bolted to it. The mat is Slaws "MyMatt'". Flywheel, motor, & arm pedestal are not attached to the plinth. The bearing(s) are modified aerospace valves with the "X" &"Y" portions separated from each other. They are made out of aluminum with a thin layer of hard coat applied to the surfaces that make contact with each other. The plinth & motor sit on springs while the tonearm pedestal & flywheel sit on Isoacoustics feet. It's been a fun project.

 

Please keep us updated on your progress.

@boxer12 That sounds amazing! Love to see pics.

@thenightshade I'd go with springs over Sorbothane feet. Rubber O-rings may also work better on the bearing. 

Thanks Brian!  Been negligent with the system pics... I need to do that.