Maximum Cartridge Tracking Force for long LP Life

@billstevenson, 

I have an ART20, VTF 1.8 grams, mounted in my SME 3009 series II improved with fixed head shell.  It never occurred to me that this was outside of design parameters until I read this thread. 

How is your ART20 outside of design parameters?  It's perfect - Dual Moving Coil Stereo Cartridge | AT-ART20 | Audio-Technica | Audio-Technica.  The VTF is fine and although the effective stylus mass is not known, I am quite sure that it follows common design practices and is down around 0.3-mg.  

If the goal is to maximize LP life, then you’ll want to keep your LPs and stylus squeaky clean. Cleanliness can be as critical a factor as VTF.

Mathematics and probability.

A cartridge stylus accurately tracking at 1.5 grams wears the groove incrementally over time.

A cartridge stylus accurately tracking at 3 grams wears the groove incrementally over time.

Friction produces heat and wear, more so if there is no lubrication.

Which of the two above examples would produce the most friction?
 

Mathematically and in all probability if both styli have the same profile, the one tracking a record at 3 grams.

@antinn 

How is your ART20 outside of design parameters?

That particular version of the SME 3009 tonearm, the Series II improved with fixed head shell, has calibrations for Vertical Tracking Force (VTF) which max out at 1.5-grams.  The calibrations for anti-skating match the VTF ones, one for one.

It is easy enough to increase the VTF by screwing the main balance weight forwards, using a stand-alone scale to set the VTF, but then you run out of calibrations for SME’s anti-skating contraption, at least in theory.  The simplest way out is to obtain a heavier anti-skating weight and mentally recalibrate what the string positions mean!

Bill’s VTF is only 0.3-grams high, and my AT cartridge is 0.5-grams high.  I certainly would not attempt to run an SPU cartridge in this particular species of SME 3009 tonearm.

@billstevenson @antinn 

This is a bit of a diversion, but I was thrilled to discover that the review of the AT-ART20 referenced on Audio Technica's website was done on a Holbo Mk2 air-bearing system.  I have a new Holbo waiting for me to get home and install it.  When I do, I will take my AT MM cartridge out of the SME arm and put it in the Holbo.  Then my old Shure V15 with a new Jico stylus can go back where it belongs in the SME tonearm, with a Garrard 301 table.

I intend to write up my experiences with the Holbo and its tangential tracking tonearm in the next few weeks.  I can say that the delivery from Slovenia to Australia was absolutely painless and much faster than I anticipated.  It just appeared, no customs issues at all.

The tangential tonearm, which floats on a 10-micron thickness of low-pressure air, eliminates both Horizontal Tracking Angle errors and the need for any anti-skating device.