setting VTF with a digital guage

Tketcham: I am not sure I understand your chart of height and weight. Could you clarify?

I will admit to investing in an Ortofon digital gauge, which is kind of pricy, but seems to put the stylus in about the right place.
ortofon

You don't need a digital gauge... The Shure thing gets it approximately right...then use your ears... On the VPI arm use the large Allen wrench to move the internal counterweight (accessible from the hole in the back of the arm tube) back and forth until you hear what you like.

What range of variation are people getting? I have a cheapie digital scale I got off eBay and I don't get a variation greater than +/- 0.05g irrespective of where I put the scale: on top of platter or next to it (given my set up, this puts the scale at least .5 in. lower). I believe I can hear differences in this degree of variation. However, in my opinion, accuracy is not essential here. Precision is more important. One has to locate the correct vtf by ear anyways, so once one is around the area one wants it's just a matter of being able to locate the preferred setting again after repeated testing of different vtf's.

Even for someone like me who adjusts vta for every record, taking a scale out for every record seems insane.

Despite my suggestion to develop a calibration factor for the Acoustech, I didn't go to that much trouble to set VTF. Close enough was good enough.

I had (and liked) the Acoustech digital gauge but it failed on me. I went back to using a Shure gauge and it works OK, but I missed the convenience and accuracy of a digital gauge. I bought one that was built like a tank (unlike the more delicate "analog" ready gauges with the thin platforms) and made a platform extension out of a credit card that was the same height as my setup LP. Works great; easy to use and reliable.

For Kiddman: Although not precisely consistent, there's a relationship between record weight and record height (thickness). I use a thick 180g LP as a reference to set up a cartridge and use a 0.5 mm Herbie's Donut platter mat to partially compensate for 120-150g LPs to keep the SRA within a relatively optimal range. I also bought a 0.8 mm Donut mat for very thin LPs (Dyna-Flex) but most often just use the 0.5 mm mat. For 160g LPs I either use the mat or use a bare platter depending on the mastering.

It sounds complicated but it's not. I can flip the Donut mat onto the platter or remove it in a matter of seconds. And it does make enough of an improvement to be worth the cost and effort, though I probably wouldn't bother buying the 0.8 mm mat.

Regards,
Tom