Question on FR 66s

Strange, actually, I should say that the problem is mainly with my Air Tight cartridge. Forgot to mention that Kiseki has 5 sets of mounting holes along its body so I have more range to mount the cartridge. Air Tight only has one set of holes to mount the cartridge. If I use 230mm, there is no problem and I have a bit of room to spare. Just at 231.5 only.
I assume that the center of the tower is where I would measure P2S.
May be it is just the Air Tight cartridge? I assume that all headshells have the same dimension, lenghtwise but assume that each cartridge will have a bit of a different dimension lenghtwise, as far as overhang is concerned.

On FR66s, I only try Koetsu with Oyaide headshell so far and I have a couple of mms to spare in front.

I did not have problem with Koetsu on FR64s in the past either but only at 230mm.

Halcro, if I remember correctly, you have Dyna XV-1s. I will try to mount XV-1s on one of my headshells and see how much wiggle room I have.

Now I seems to amass quite a few protractors, beside Feickert and Clearaudio, I do have 2 mint protractors for Reed and 10.5 arm. I have no idea what logarithm Clearaudio uses. Elsewhere on the net, someone mentioned that it looks like a Dennesen protractor but I am not sure if they only talk about the look or the actual null point. I burrowed my friend's Dennesen protractor once a long time ago and compared and I thought the nullpoint was pretty much the same. Generally I just prefer Clearaudio over Feickert just because it is much easier to see silver protractor with black line than black protractor with white line which my poor eyes really struggle to see especially with Koetsu and Air Tight cartridges where the stylus is hidden under the body of the cartridge.

Yes.....centre of Tower is Pivot point.
I do have the Dyna XV-1s which is currently mounted to one of my FR-66s arms..........but I also have 38 other cartridges ready mounted in their own headshells and all of them have been played on the FR-64s as well as the FR-66s.
In fact......with ALL my cartridges......I set them up on one of my FR-66s arms (which I can do very accurately using Dertonarm's UNI-Protractor).....and then simply swap them between 4 of my other arms (the Copperhead has no headshell and the SAEC WE-8000 S/T has its off-set angle built into the headshell).
My point being Suteetat......that I have had no mounting problem with over 40 cartridges in either FR arms......and I even had an Orsonic headshell which caused no problems?
Perhaps the Airtight is a 1 in 50 cartridge?........but something is certainly untoward in your experience?

Halcro, thanks for your help. It is kind of strange, Air Tight sounds fine with 230mm P2S being close to the furthest point away on the headshell with Baerwald. I think that if my XV-1s can be mounted with plenty of wiggle room with both 230/231.5 mm as you have with no problem then I just assume it is one of Air Tight quirks. If I have similar problem with XV-1s then I guess I do have a problem (keep my fingers crossed!)

At the Munich High End Show is a Manufacturer with a new calculated Alignment System (some here know it) and what amazed me totally was the amount of visitors, dealers and Importers who showed a very huge interest in that. Whenever I was in the area of that their arguments were ALWAYS the same: way too much nonsense out there (I agree with that btw.). I also saw wrong alignments, Arms with a Geometry which made me wonder....and the discussions among audiophiles what .... everyone is a specialist with deep knowledge :-)

The problem with using protractors based on fixed pivot to stylus and overhang is that any deviation in mounting distance or cartridge/headshell constraints render the protractor useless. I prefer to use a universal protractor such as the 'Stupid' Universal here
http://www.vinylengine.com/cartridge-alignment-protractors.shtml
It uses 2 inner and outer null positions and you have to adjust overhang and alignment of the cartridge together to minimise the error.
Using a universal protractor will enable you to align for any mounting distance distance from 230-231.5mm.
For the FR64S and Dertonams suggested 231.5mm, you cannot adjust it via the headshell as Halcro suggests because you will end up with a different overhang. You must have the mounting distance correct.
Going from 230mm to 231.5mm mounting distance is a tiny reduction in tracking error, but having said that I have mounted my FR64S at 231mm and it sounds much smoother than 230mm.
The other factor in Dertonams recommendations is using an outer null point closer to the inner null point which will increase tracking error on the outer grooves but reduce it on the inner 2/3 of the record to provide better tracking of inner grooves.
You can easily make your own protractor with revised optimisation of inner grooves by using the Baerwald template above and simply moving the outer null point/grid closer to the centre.
Interestingly the Naim Aro that I own uses this same philosphy as Dertonams recommendation of optimising the geometry for the inner grooves.
I prefer Baerwald A for all my pivoted arms including the Dynavector which was designed for Stevenson.