Multiple arms, multiple cartridges and geometry?

Dear Henry, You need, it seems, to start a new. I hope that
you own no more then 400 Lp's so you can rearange them according to the distance of the outer groove to the spindle. Assuming 3 geometries you will have then 3 kinds
of LP's collections which is 3x more then we, the other, have because we own just one collection. Then you should mark all your tonearms according to the new ranking or geometry while the same should be done with the carts/headshell combos. This way you will have 3 kinds of every kind while thanks to the markings no confusion
will ever (more) occur.

Regards,

Dear Nikola,
Que??.........
Lew.......you're right about my ability to 'massage' the spindle to pivot distances for all my arms.
I'm thinking......and I may be wrong (need to check the Vinyl Engine formula)....... Whether I can adjust the P to S dimension of all the arms to have a uniform 'overhang' dimension?
Will that allow for a 'common' interchangeability?
Regards
Henry

Dear Halcro: I think that I don't explain to good or that you did not understand what I posted, here again:

first I don't know why you want differnt geometry alignment for each tonearm ( Baerwald, Stevenson, L¨fgren or what ever. ).
If you need full interchangeability you must choose one geometry alignment for all tonearms.

When we choose in that way, example: Löfgren B, even if the tonearm effective length is different from each tonearm we can force the calculations to one effective length for all the tonearms, in this way the overhang and offset angle will be the same to all tonearms and with full interchangeability.

Subject is to choose the " right " effective lenght value that permit the cartridge overhang set up for all tonearms. So, if for example you choose: 260mm that means that all tonearms must be mounted to conform that effective length minus the calculated overhang.

This could do it or not depending how large are the true tonearm efective lenght differences between each of the four tonearms. So, not always is possible to have that full interchangeability.

Regards and enjoy the music,
R.

Henry - for the arms you use that have detachable headshells, surely if you use a headshell that has slots, hence the ability to alter the overhang and alignment, then you can set each cartridge up and the only changeover issues would be tracking weight and VTA. I use to build easy VTA adjusters by tapping a metal block and using a fine thread screw to put under the arm lift. If you recorded the optimum for each cartridge/arm then it becomes easy to adjust.
Failing all this - buy 2 more TT's & enough arms and you can at least get 24 of your cartridges running simultaneously.

Dover,

and the only changeover issues would be tracking weight and VTA.

That's what I thought and the principle I have been operating under?
However.....I fear that is not the case?
The effective lengths and overhangs being different for all my arms......means the arm geometry is not easily transferable?

Raul,
I agree that I need to accept the same geometrical alignment for all the arms I wish to use with detachable headshells......say Baerwald?
I can appreciate that I can adjust the P to S distance of each arm so that the 'Overhang' can be the same.......but I don't see how I can adjust the effective lengths between 222mm, 230mm or 295mm to be the same? :-(

Can you possible explain a bit more thoroughly?

Cheers
Henry