Installing cartr.:slide it all the way to front?


Hi
When installing Shelter 501 MC in Rega RB 600,should i slide it all the way towards the front of the shell or leave it somewhere in the middle?Does it really matter?Please,advise me on that.Thanx.
overhang
Doug,can you please tell me what is step 2 in setting up my cart.The distance from spindle to pivot is 216-218 mm.very much appreciate your help.
Mario_b asked:
Why can’t one set the cartridge overhang using linear measurements as per the arm’s manufacturer for the designed tracking arc: Then use compassed circles for Baerwald, Stevenson or whomever one divines to have the null points one’s looking for, and use these to set just the stylus tangent? What am I missing?
Here's what you're missing: this method assumes one can attain stylus-groove tangency at DIFFERENT pairs of null points with the stylus travelling on the SAME arc. That is not possible.

On any given tracing arc, assume the cantilever is tangent at two points A and B. This is only possible because the cantilever is travelling through a given moment of arc, from which it receives a given angular shift.

Now choose two new points, C and D, located on the same tracing arc but separated by a different moment of arc than points A and B.

Make the cantilever tangent at point C and check its orientation at point D. It will not be tangent. Why? Because it experienced a rate of angular shift that was suitable for the (different) angular seperation of points A and B.

Changing alignment schemes will always require changing the tracing arc. Tracing arc protractors (like the Wally or your proposed DIY) are wonderful and easy to use, but like any protractor they are specific to one particular alignment scheme.

Doug,

Thanks for taking the time to explain this. I'm digesting - my mind coming to grips with what you're saying like a cold engine.
Instead of thinking and postulating, I'll apply these test that you have been good enough to provide in actual hands on experiments - and hopefuly break through to that Eureka moment that has eluded me up to this point.

On a side note, I have used the TTB mirrored protractor as well as oak tag (the latter atop a thin dynaflex type record). I certainly do like the mirrored gander that the TTB device affords. One note of caution with it to anyone with less than nimble hands; the alignment channel grooves are deep and rough and can catch and wrench a stylus/cantilever in a heartbeat.

Thanks again for your patience, Doug.

Mario
Dougdeacon, my rega300 installed on an AlexMkIII has the following geometry. Pivot to spindle at 222mm and stylus nulls are at 64mm and 120mm, which seems to be close to the figures that you have mentioned. Cartridge is a BPS. I thought that those figures might be of assistance here. I used a protractor that was published in HiFi World.
Salut, Bob P.