SME 3012 Alignment

[wer]

Surely this must have happened to others as well, yet i only found a reference to a 3009.

The P/S distance is given as 294mm. I printed out a C. Hoffmann protractor using Baerwald strategy, but with the cartridge pushed back in ther slots of the HS as far as it would go, the overhang was at least 3mm more than  it should be.
Pushing the tonearm back on the mounting base as far as it went the P/S is now 297mm (i know i should have more leeway, but i screwed up the base plate measurement  ), and i barely made the alignment.



Just to make sure, i tried another cartridge in another headshell, but it also needed pushing back to the very end in the HS.

Are the original SME headshells shorter?

[analogadikt]

Are the original SME headshells shorter?

I don't think so. The original does not have any slots, only mounting holes. Any sliding of the cartridge when using the original headshell has to be done at the baseplate. Compared the original with a Technics headshell like the one you have, the SME mounting holes are lining up at the midpoint of the slots on the Technics.

Regards,

[wer]

Thank you Anwesh.

I have a bit of a problem with that, because every time you move the complete arm, you create a new S/P distance, and have to recalculate your overhang 

If the mounting holes of the SME headshell line up at the middle of the slots, it means that you can't really get an accurate alignment 

[be.audiophil]

You need to drill the long sleeve as specified. In addition it will work only when using original SME protractor and original SME headshelll with fixed cartridge position or SPU cartridge in G she'll.

[wer]

You need to drill the long sleeve as specified.

Rolf, could you please explain that?

[be.audiophil]

Within the manual you'll find the dimensions for this lng sleeve that will have it's center at 294 mm. I'm talking about that oval hole the arm needs to be moved around it's pivot.

[Nick]

This might help. You'll need to register if you haven't already, but it's a real goldmine for info; downloadable manuals, templates, the lot. Brilliant!

http://www.vinylengine.com/library/sme/3012.shtml

[wer]

Thank you Rolf, now i understand.
Of course you can move the arm in this slot, but every time you change thde P/S distance you have to do a new alignment calculation. Admittedly the differences are not immense, but they might be significant, particularly if you have an esoteric diamond tip.

Yes Nick, it is indeed a goldmine, but registering may be very difficult for a large number of LH patrons because the paranoic owner of the site slapped a lifetime ban on us 

[Nick]

Happy to email the documents to you.  What do you need?

And why the ban if that's not a daft/tactless question? (you don't have to answer.... )

[wer]

It is a long story Nick, but it seems that the site owner considers references to Lenco as spam.

If you consider "paranoic" an exaggeration, kindly read this excerpt from the Site Policy and form your own opinion.

Notes

The Vinyl Engine takes spam very seriously. To fight spam and other site/forum posting abuse, visitors found responsible may have personal information published on the site and/or disclosed to 3rd parties (eg name, email address, IP address etc) and reports will be made to the spam abuse department of their Internet Service Provider. In signing up for any Vinyl Engine website services you are agreeing to have this information disclosed at our discretion.

[bert]

 
    Hey Wer ,I think Rolf nailed it . ....... will only work when using original SME protractor .

  I haven't got one ,consequently I find myself in a similar conundrum despite my arm being unfettered , i.e. not mounted to the deck .

 What o/hang did you end up with ? Mine's about 15 mm . Why do you use Baerwald ? I was under the impression SME recommended  Lofgren ?

[wer]

Hi Grayam, iirc Baerwald is the same as Lofgren A.

I am now at 302mm P/S distance, which calls for an overhang of 12.3mm and 16.9 deg offset using 58 and 146mm groove radii.

[jervill]

An aside. This is the protractor I used:

http://flashdaiyo.exblog.jp/4941657/

I couldn't get a lot of movement on the baseplate hole as I miscalculated how the interconnect attached to the base would limit movement. This protractor happened to line up more 'flush' than the other protractors I tried so I went with it. I don't know which model alignment it follows as my Japanese is non existent    Anyway, just mentioning.

[wer]

It would be Stevenson, which always turns out to have the shortest o/hang.

The protractor is not much different from the Hoffman one i use (see picture in opening post).

There seems to be some magic about the 3012, i mismeasured the centre of the baseplate hole by about 12mm 

[be.audiophil]

SME 3012 protractor can be bought here

http://www.ebay.de/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.Xsme+3012+protractor.TRS0&_nkw=sme+3012+protractor&_sacat=0

Originally SME 3012 Series 1 and Series 2 should work with 11 mm overhang, Series R with 13,2 mm.

In addition we should remember SME/EIA standard that defines the distance between needle tip and bayonet flange to 52,5 mm. Thus leads to a trick that makes alignment of SME arms very easy. You need to mount your cartridge in parallel to the middle line through the headshell and with a distance between needle tip and bayonet flange of 52,5 mm as it is done with SPU cartridges and in accordance to EIA standard. Afterwards you need only to move the SME arm in its pivot and check the overhang by pointing with the arm at platters spindle. That´s all.