Has anyone tried driving a B Belt direct on the flywheel? I'm thinking there might be sufficient surface area to do that for a modest load. I'm considering this for the ST-3 drive. Lots more flexibility in sheave size. A 10" sheave would match my desired 750 rpm. A single B belt is more than adequate according to my belt chart.

BruceM

I have done this on many of my systems.

Here is a unit I built for sale 2 years ago. It uses two "B" series belts to drive a 4kw generator.

The belts did not flop on their sides due to belt tension, however I would recommend using a "banded" belt where the

common backing keeps the belts from rolling.

https://www.youtube.com/watch?v=IbpiYeCJbNsAs you know V-belts are designed to carry load on the sides of the belt and not the inner surface. I counter this by over-sizing the belt drive by a factor of 2.

So, if 1 belt can normally carry the HP, I use 2 belts.

The surface area of the flywheel is so great that no slippage occurs.

My suggestion is to use a multi-ribbed "3V" series belt and a "3V" pulley on the ST-3 head. The 3V series belts have a much higher HP capacity than the "B" series. They also conform to smaller diameter pulley's (sheaves) better than a "B" series belt.

On my current listeroid I run a 2 groove (3V section) pulley on the generator and routinely pull 2.5 kw with no slippage (2.5 kw gen head).

When running the 4kw gen head on this engine I used a 3 banded "3V" belt and a 3 groove pulley.

If you want to over-engineer a bit, use a 3 groove pulley and a 3 banded 3V belt. Get the banded ones and not 3 individual belts.

the banded version is necessary to stop the belts from wandering and flopping over on their sides.

Here is another example of a unit I built using a 2 banded 3V belt.

The head has a 3 groove pulley but I only used 2 of them.

This generator can pull 3kw.

https://www.youtube.com/watch?v=f-hl2yfODMEcheers,

Veggie