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How to use Feickert Protractor on SME V Tonearm

I just bought a Feickert Next Gen Protractor. So far I just measured the spindle to pivot distance, it was set to 212mm. This is using a Denon DL160 cartridge setup using a paper protractor from the web. The spec for the spindle to pivot distance is given as 215.35mm. My turntable is a Gyrodec with mounted SME V tonearm. So I started thinking about how this would work using the Feickert protractor, each time I move the sliding mount of the SME V, I would then need to adjust the position of the sliding spindle to pivot distance of the Feickert protractor and thereby moving the alignment point. This seems like a never ending loop of adjust SME V slide adjustment, then re-adjust the spindle to pivot distance on the Feickert to get the correct alignment. Am I missing something, it seems like a very interative process to use the Feickert Protractor with a SME V tonearm. I bought the Feickert to make alignment simpler and more accurate. How do others use the Feickert Protractor to align the SME V tonearm cartridge?
hartonr
hartonr OP
4 posts
 
Oscar44, thanks. That is what I thought but wanted to hear from somebody that has used the Feickert with a SME V arm. Anybody else who has the SME V arm and uses the Feickert have any other advice? Should I start out the alignment setting the arm to 215mm and then go from there?
larryi
3,962 posts
 
If you like the chosen alignment for the protractor that SME supplies, that is a precise way to get the alignment right. I like those bespoke protractors that require you to get the arm to align with a profile of the arm that is drawn on the protractor. The Basis Vector utilizes such a protractor and if you are off by just a fraction of a millimeter, the image will be off by a significant amount.
hartonr OP
4 posts
 
I bought the SME V arm used and its missing the rubber grommet that fits onto the SME provided protractor alignment tool which fits it to the spindle, plus I have read that the Feickert protractor is much more accurate than that tool.
larryi
3,962 posts
 
Hartonr,

Without the grommet or a means to perfectly fit the protractor around the spindle, your SME-supplied protractor will not be very accurate. If you have the spindle to pivot distance accurately measured, I think that the Mint protractor mentioned above by others is the best way to go. They will make a protractor for that specific distance and with the correct diameter for the spindle hole for your turntable (spindle sizes vary by a significant amount (up to 2mm in diameter). What I really like about the Mint is that the mirrored surface is designed so that the lines come into sharp focus (no double images of the lines) only when you have moved your head into the correct position to correctly view the cantilever alignment to the markings. This correct head positioning IS critical to a super accurate measurement. Also, because the protractor is made specifically for your spindle to pivot distance, the placement of the null points is such that you do not have to iteratively move the protractor. It is the easiest thing to use and VERY accurate.
dougdeacon
3,338 posts
 
Larryi,

Fully agree with your latest, provided that SME owners pay heed to Albert's initial post. Use of a Mint (or any arc) protractor with an SME V requires that the user provide Yip with their cartridge's cantilever length (i.e., the hypotenuse of a triangle drawn between the stylus tip and the two cartridge mounting holes, when viewed from directly above).

Lacking this information, a protractor designer could not calculate the arc any particular stylus should follow except by guessing, which Yip seems uninclined to do.

Albert correctly explained SME's naive assumption as to cantilever length, which necessitates a unique Mint (or other arc) protractor for each cartridge. Whether SME was being shortsighted or haughty is open for debate, but in any event it's a weakness in an otherwise fine tonearm.
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