Building high-end 'tables cheap at Home Despot II

On the 401 the eddy current disc should run true to avoid generating vibration, because the braking magnet is only on one side of the disc. The 301 magnetic brake is a horse-shoe shaped affair with the magnetic force transferred from the magnet itself via the two "legs" of the horseshoe, which "straddle" the eddy current disc so that if the disc wobbles a little, the effect is minimized: as the disc moves toward one "leg" it moves away from the other and vibration cancels out.

Good luck with straightening the disc on your 401. Very occasionally someone will "part-out" a 401 and sell the parts on E***.

If I've got rust in the motor should I just bail out now? I started cleaning up an L75 I bought through an ebay auction and I wasn't too happy to see rust and corrosion spots underneath. When I opened the motor up there was rust inside and rust where the plug wires connect. It spins fine but I'd just like to know if this is a really bad sign.

Hi Leisual: if the Lenco is working fine, then buy some rust solvent and clean the Lenco up and go through with it. The cleaning up part will be more work, bt in the end it will be stellar. Apparently tea is an excellent rust solvent: TEA.

Hi Mike, the disc MUST be utterly flat or it's not worth the effort (too much vibration/noise). The other option is a variac with which you can adjust the voltage/speed and remove the offending disc completely. Do as Gene suggests and wait for a spare on ePay, as a variac will reduce torque, and Torque is Sacred.

Crem, take it as an attack if you are that defensive. YOU seemed to be saying that folks at NASA were testing the efficacy of steam cleaning vinyl records. No? If they were doing this as part of a taxpayer funded activity, I consider it a waste of money. If you are just talking about people who happen to work at NASA who are doing some sort of home testing, I'd only ask, so what? That's all.

A typical 401 runs fast without the magnetic brake, so if you remove it, you need to reduce the turntable's speed. Other than a variac which reduces torque and motor RPM (and thus motor inertia) another way to alter the speed downward so it's accurate is to CAREFULLY turn down the step on the motor pulley. You can do this with a small metalworking file as the motor and pulley spin, checking frequently to see how the speed is being affected. I'd stop when you reach around 0.3% fast. Do all this when the motor is fully warmed up; it will run slow at first when you turn it on cold (probably still within 1%) but will speed back up as it warms up.

Since the motor will be spinning at close to 1800 rpm as you work on it, the end result will be perfectly concentric.

I'd recommend buying a replacement pulley from one of the vendors on E*** selling new ones, grinding it down, and keeping your original in a safe place.