pressure cutting stylus

[studiorp]

Hello to all, I don't remember if I had already asked here this question, but which is the right pressure in grams of cutting stylus on disc surface ?
Thanks.

[Jccc]

I would also like to know this as well. That way i wont be wearing out the needle

[studiorp]

When I had posted here this question, I had just start to do experiments cutting makrolon from 2 mm.
Now I am cutting with steel needles, but the right number of grams I don't know. For know it you must cut a silent groove ( I know it's very difficult do this, but with a good ear ... ) without music adjusting the right pressure and then see the grooves on a microscope. Then you put the needle on a little pocket scale and measure. Consider that my cutting head weight about 230 grams.
This the system that I would use.

[audadvnc]

According to the Westrex manual I work from, correct cutting stylus pressure is in the 50-75 gram range. I bought a spring style gram scale off eBay for $4 (similar to a fish scale), it does the trick.

If you make it too light, the stylus will wander off the disk with any non-flatness; too heavy and the trackball will excessively score the surface of the disk.

[studiorp]

Hmm, interesting audadvnc, and thanks for this info, but 50-75 grams is an universal number and it's valid for all cutterheads, or only for pro world ?

[audadvnc]

Consider the function; you are cutting a groove of lacquer on an aluminum substrate; you don't want to cut too deep or too shallow. Like Goldilocks' porridge, you want it just right...

I would guess that the same general stylus weight would be appropriate for any stylus/head combination that uses an advance ball on an Apollo/Transco style lacquer disk, such as the Westrex 3B I use, or any mono head.

For a head that is attached to a machine with auto-variable stylus depth mechanics (such as a late model Neumann), you will need to reference their instructions.

[Angus McCarthy]

I've never bothered to actually check the weight on my 6N. With that kind of carriage (without an advance ball) you have to just dial in the correct tension on the spring until things sound quiet.

[audadvnc]

That's how the Westrex is adjusted too, by spring. Since there is an advance ball for setting the groove depth, my limits in setup are mechanical: at one end, the stylus may be too light, not have enough weight behind it to stay buried in the groove; alternately the weight is too great, causing the advance ball to carry the excess force and aggravate scuffing of the lacquer surface. Once you're safely within those limits, then you can adjust, and season to taste.