If it's light it need Mallory metal. If it's heavy I'd turn the counterweights down first and then drill small holes.

You'd have to have a Flintstone style bobweight to have end weights that light.

If they can't turn the counter weights and drill some holes maybe need to start over.


Just reread OP and they want it external. How heavy is the bob weight? To ADD that much weight the bobweight must be 2500 grams. Or more.

Something is wrong