Uni-Protractor Set tonearm alignment

Tom Mackris.
Of course you are right when you say that the extra stylus tip-mounting holes distance cannot simply added to the manufacturer's stated effective length for the tonearm. In fact I was aware of that. What I was trying to illustrate was a way to measure the actual effective length (rather than calculating it) by effectively drawing a line (but in fact using the Feickert trammel to simulate it) from the stylus point to the arm pivot 'as the crow flies' (and then measuring it). Surely this (leaving aside for the moment any practical difficulties in achieving it) would give the correct measurement (?).
regards.

I understand what you were trying to accomplish, Pgtaylor. This was an illustrative example for those who haven't worked through the math.

BTW, do you really think that the Feickert has the precision to measure to .003"? If you can do this with that tool, you're a better man than I am.

Cheers,
Thom @ Galibier (the "h" is silent)

Dear Thuchan: I like almost all use audio after market items, I own no least than 9 different protractors but you know why?: because my ignorance level over time.
Fortunately that level improve over the years.

Regards and enjoy the music,
Raul.

Dear Pgtaylor, the SME V's alignment is indeed a very special problem. The Schroeder is different and offers the user a wider range of options.
But back to the SME V, which was when introduced anticipated like no other tonearm ever before or ever after.
The SME V is unique in the sense that it's offset and effective length (at least it’s designers thought so and intended it to be that way...) are fixed and pre-determined. Problem is, that SME Ltd. took for granted that each and every cartridge manufacturer would strictly follow IEC standards regarding stylus-mounting slots distance. Which of course they did not.
Now there is the legendary SME slide base to allow sliding the whole tonearm back and forth. That way the arm kind of "moves to the wanted alignment spot".
In theory....
The fact that the fixed offset angle of the fixed headshell isn't really a feature which eases things in any way did not really appeal to the SME engineers in their strive for setting the technical frontier in tonearm design.
Now can one align the SME V precisely with ANY cartridge mounted ?
Yes.
As long as the protractor reacts to a change in P2S as well as to a change in effective length automatically.
The UNI-Pro individual templates do offer for a given tonearm (and there is a individual UNI-Pro template for the SME V of course) an optimized spot of alignment - the corresponding effective length and ( in the case of the SME V ) the P2S are direct results of the alignment and are automatically generated.
Without any calculation required by the user.
In the case of the SME V (which really is a very special issue) there is however way less options for variations in alignment/calculation curves.
The SME V is a super strict 9"/Baerwald IEC-standard tonearm.
You can't really align him a Loefgren or Stevenson curve with good results.
I hope this answers your question, but you are welcome to get in touch directly in case you have further questions regarding your SME V.
Cheers,
D.

Dear Thom_mackris, indeed, this is rather the fine print in tonearm alignment is may already be well beyond what a good portion of the analog department want to muse or think about.
I just wanted an instrument which provides the best possible universal alignment results with super simple handling and comfortable feeling.
I will continue to design a few devices which will nicely work with and are based upon the UNI-Pro.
A super precise and truly new P2S-measuring tool will be introduced end this month. This will come together with an easy goniometer to determine offset-angle fast, easy and precise.
I am considering this rather an add-on of interest only for a few dedicated audiophiles who really want to study the subject.
Furthermore - also end this month - there will be a special USB-microscope w/strong cold light to be used with the UNI-Pro and which can be exchanged with the magnifier and uses the same cut-out frame on the UNI-Pro's main frame as the magnifier.
This will allow magnification 20x to 200x (similar to the Dino-lite) and will come with all features, adjustable and with software for Linux, Windows and Mac.
Plug and play within 10 minutes.
Allows view of the stylus on the spot on your screen with actual measuring tool and photo option.
This will allow the most enlarged and "recordable" look and will further ease as precise alignment as possible ever to the ones among us who are a bit troubled by eyesight showing our advanced age...;-) ....
Cheers,
D.