Finding the horizontal pivot point on my OL Silver (modded RB-250) was trivially easy...
1. Mount the arm to the table (no cartridge needed, keep the stylus guard in place if it's already mounted).
2. Stick a piece of scotch tape across the top of the bearing center.
3. Using a fine, felt tip pen, make a tiny dot on the tape where you *think* the pivot point is.
4. While viewing your dot from directly above, swing the arm back and forth through its arc several times.
5. Move the tape as necessary until the dot remains stationary while the arm is moving. Voila!
6. Measure from center of TT spindle to center of dot, using a fine lined metric ruler. Keep the ruler level or your measurement will be artificially lengthened. Move the arm until the dot's at 222mm and tell Yip. You'll be well within 0.5mm.
7. Don't forget to remove the tape! Save it for future use if you're especially cost-averse.
This takes 2 minutes and costs $2 (for the ruler). Well worth it IMO for getting a good arm position before dropping $110 on a protractor.
Doug
P.S. No, I will not make up the tape and dot for those unable to do it themselves, whether for free OR for a fee!
1. Mount the arm to the table (no cartridge needed, keep the stylus guard in place if it's already mounted).
2. Stick a piece of scotch tape across the top of the bearing center.
3. Using a fine, felt tip pen, make a tiny dot on the tape where you *think* the pivot point is.
4. While viewing your dot from directly above, swing the arm back and forth through its arc several times.
5. Move the tape as necessary until the dot remains stationary while the arm is moving. Voila!
6. Measure from center of TT spindle to center of dot, using a fine lined metric ruler. Keep the ruler level or your measurement will be artificially lengthened. Move the arm until the dot's at 222mm and tell Yip. You'll be well within 0.5mm.
7. Don't forget to remove the tape! Save it for future use if you're especially cost-averse.
This takes 2 minutes and costs $2 (for the ruler). Well worth it IMO for getting a good arm position before dropping $110 on a protractor.
Doug
P.S. No, I will not make up the tape and dot for those unable to do it themselves, whether for free OR for a fee!