Tom Fletcher, one man's work.

[James D]

Tom uses non-stretch belts. No one who is serious uses rubber belts anymore... or any other stretchable material. The best belts are made from things like 1/4" backing tape, cord or pre-stretched monofilament line.

Also if the motor isn't turning it can't be exerting a tension on the belt - or can it

James

[pre65]

Hi-my belt drive creation runs a small dc motor to turn the platter and although it will start of its own accord only runs at 2.6v (less when it was turning the inner platter) and is quiet.if you wind up the voltage the motor gets noisier as the speed increases.

now there is no belt/motor lurking under the platter it gives me room for extra mass to preserve the rotating inertia.

who would have thought that a motor so weedy and a platter so heavy could give such (reported) superb results.

Philip

[pre65]

[quote=James D]. No one who is serious uses rubber belts anymore... or any other stretchable material.


Hi-i'm only a bit serious !


Philip

[IslandPink]

James, the drive belt on the Hyperspace is very soft , stretchy rubber.

MJ

[James D]

I just knew you were going to say that

So how does it work with the motor stalled?

I was sure Tom used a non-stretch belt on the turntable I played with (a friends) - a Dias... but I maybe remembering it wrongly... DTVJ has a Dias maybe he will correct me on that.

In any case Tom reduces to minor proportions the influence of the belt on the platter by keeping the belt drive system very low energy and increasing the mass of the platter to enormous quantities. The German high mass belt drive decks do the same and they are also solid suspension. They all sound very good but don't have quite the life of an idler or the enormous weight and solidity of a great DD.

Thats my story and I'm sticking to it

James

Tom Fletcher uses stretchy rubber belts and heavy platters. The heavier the platter, the better the NAS!

Decks from the Hyperspace upwards also use an 'oil pumping' bearing which are very low friction - remove the belt and give the platter a spin and it takes minutes to stop turning.

My motor is such low torque that even when the belt is removed it doesn't have enough grunt to turn itself so, as James has said, the belt drive system is very low energy.

His decks are certainly different to those lightweight, bouncy, belt drives that dominated the market for so long.

[Greg.]

Oil pumping is not unique to NAS. Michell do it as well, maybe even first. Actually, is this really an issue? A well engineered bearing with close tolerances properly lubricated and in static suspension is probably as good. Hense Garrard 301/401 and maybe even Lenco.

Best wishes,

Greg

Absolutely.
The 'self lubricating' bearing idea is not unique, but it is eminently sensible. As for close tolerances, my platter weighs more than an entire Kondek and takes at least three times longer to settle down than the light LP12 inner platter ever did, even into the 'improved' Cirkus bearing.

I suspect that it would be almost impossible to find a deck that combines the reported strengths of good Belts and Idlers.
As a sweeping and uneducated statement: the Idlers seem to have drive aplenty, the massy Belt drives seem to have extraordinary low level retrieval. Both qualities would appear to stem from their design approaches, one uses torque to drive, one loses torque to give a very noiseless system.

[IslandPink]

" How does it work with the motor stalled "
...it doesn't !
But the motor pulley vibrates a bit and it sits there until you turn it up to maybe 2/3 or 3/4 of the running speed, then it takes over .

The Hyperspace and upwards have an oil-pumping bearing .

The Hyperspace with platter approx 13kG does not have the bass solidity ( imaging ) and energy/timing of the Garrard 401 , 301 , despite the platter mass . I think it would be very interesting to cobble-together a hybrid using the Hyperspace but with a more powerful motor and a non-stretchy belt some time .
The tonal clarity and quietness of the platter/motor arrangement is definitely superb and Tom has done good work in this way .
Bass is btw certainly better and lower-extended than an LP12 which I used before .

Mark

Thanks for that informed input Mark, especially as it corresponds with my guesswork!
I must weigh my Mentor's platter, I think it would fit in somewhere between the Hyperspace and the Dais/AnnaLog,

I must admit, even before this thread started, I had been thinking about a non-stretchy belt, or cutting my old spare to make it tighter ... hmmmm, get the unfinished amplifier and 'speaker work finished first methinks!