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Rear arm on VPI Classic 4 Turntable

Has anyone ever put a rear arm on a VPI Classic 4 turntable?  Does a 12 inch arm work comfortably at the back or is a 10 inch arm better?  What hardware is needed? How difficult is it to install - and use?

I’m a unipivot wand arm swapper.  I have 5 12 inch JMW 12 inch wand arms.  I was thinking of adding a 12 inch gimbal to the right sided arm but want to preserve a 12 inch unipivot for my other wandarms.

I am turning to the community for advice because try as I might I cannot get VPI to answer my emails or calls.  They seem to have abandoned customer service for some reason  I do love the turntable though despite being ghosted.

Useful input appreciated!

ulcerdoc
elliottbnewcombjr
7,731 posts
 

lewm

I agree with you, I've seen one at VAS, it's very hard material, but still .....

wlutke
757 posts
 

Titanium counterweights?  Can find only Tungsten.  angel

devil

smiley

lewm
14,669 posts
 

Maybe that is because tungsten is very dense, meaning has very high mass vs volume, and so is well suited to use in a CW.  Whereas, titanium is known for its strength to weight ratio, is less dense than steel for example, which means you need a big chunk of titanium to provide as much CW as a piece of tungsten that is about one-fifth the volume.  (Density of titanium is about 4 and that of Tungsten is about 19.) The CW adds to effective mass in relation to the square of the distance of the center of mass of the CW to the pivot. So to minimize CW, tungsten is better because you can get a smaller piece of it closer to the pivot. Titanium is not well suited to the job.

wlutke
757 posts
 

Of course.  “Titanium“ was mistakenly used instead of “tungsten” earlier in the thread.  Surprised nobody caught that.  Just poking a little fun (angel, devil, smiley).

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