How to set arm weight on SME?

madmax

I can't find my manual and didn't find this info with a search. I have an SME IV arm with the weight setting shown as A B C D on the thumb wheel. A full turn of the wheel is some amount of weight. How much is it? I think it is either 0.5 grams or 1 gram but can't remember.

I know I should use an electronic scale but my current one does not work with this cart because it has a very strong magnet which pulls it toward the scale. (need a better non-metalic scale).

Thanks!
madmax

steveinaz

From SME:

The main so-called tone-arm in both designs is a one-piece magnesium casting which incorporates the cartridge mounting platform at the front and the counterweight support cantilever at the rear. It is of circular cross-section, heavily tapered straight, and is internally damped. At the rear the counterweight is a tungsten-alloy block suspended on a damped two-point suspension within a metal housing and "underslung" to achieve the optimum centre of gravity. It is mounted close to the fulcrum to reduce inertia, only 19mm of movement being required to accommodate cartridges of between 5 and 16gm in weight. As with the Series V this counterweight can be moved to and fro by rotating a leadscrew thumb wheel and then locked in position by moving a clamp lever. Playing weight here is achieved by first balancing out the arm with the cartridge in situ and then adjusting the thumbhole accordingly, one full turn applying 0.5gm. Naturally, on an SME, this is extremely accurate.As has been noted above, many of the component parts of the Series IV are similar, if sometimes less rarefied, to those in the V. For example, bearings of ABEC-3 tolerance are used instead of ABEC-7. These special wide contact angle bearings are made for SME in Japan. The horizontal races are 10mm diameter with nine balls and those in the vertical plane 17mm with 10 balls

madmax

Cool, Thanks! The manual is somewhere but after the move a few years ago it could have ended up anywhere. Funny because I consistantly kept everything for the table in the SME box. Except the manual apparently...