MintLP arc protractor

Take a thin piece of wood and measure 222mm, drive two small finishing nails through so the points are exposed. Measure from point to point to make sure the 222mm is correct. This will be as accurate as you can get by eye.

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!

I recently got a Mint for a Rega RB-300 on a Thorens TD-850. 222 worked fine. Dougdeacon's suggestion for finding the pivot point sounds great. You may still need a caliper (a small one) to measure the spindle diameter.

The mint LP will be more accurate. It is worth the money.

Polk432, "The mint LP will be more accurate. It is worth the money."

Perhaps true but not the question of my original post. Yip is insistent on the correct spindle to pivot distance and I want to be certain that I've measured 222mm correctly before placing the order. It doesn't take much error to be a mm off.

Wendell