Michell focus arm setup instructions problem

[Jeff123]

Hi,
Ive got a Michell focus / tonearm, and I need to replace the cart.
Ive got a copy of the focus arm setting up instructions..
http://www.vinylengine.com/library/mich ... -arm.shtml
Does anyone understand the purpose of Step 4? I thought it was to set the overhang, but I see that step 5 does this, so its a mystery.
thanks and regards,
JEFF

[JaS]

Have you got the tools referred to in the instructions

Regards,
JaS

[Jeff123]

No, but am good with trig, so can no doubt draw a template once I know the requirements.
JEEF

[JaS]

FWIW the Focus mounting template gives the original specs as:

Effective length: 232mm
Overhang: 17.885mm
Offset angle: 23.75 degrees

This makes the mounting distance 214.1mm and the alignment about as close to Baerwald IEC as you are likely to find in manufacturers specs

http://www.vinylengine.com/tonearm_alig ... =calculate

Any Baerwald 2-point protractor will give standard alignment when mounted at 214.1mm.

Regards,
JaS

[Jeff123]

Thanks for the info.
I concluded that step 4 was setting the effective length by adjusting the cart position, ahead of step 5 which set the overhang via the moveable pivot center.
Looks like Im all set now.
thanks again,
JEFF

[audiobrit]

I don't know whether this solves the anomaly or not, but John Michell gave me one of these arms many years ago, along with an SME mounting plate for my GyroDec. The reason for an SME armboard is the fore-and-aft (or, more properly, I suppose, diagonal) adjustment; if the armboard has an oval hole (not a round one as shown) with overhang adjustment screw (7 on the illustration) there's a good 5mm of adjustment possible. (If you can't drill an oval cutout, as per an SME 3009 armboard, the hole should really be 35/36mm diameter. The base plate is sufficient diameter to fully cover it.)

I never actually got around to trying it out properly, since one channel turned out to be dead: I've finally got around to looking at it, and rather mysteriously, the core of one arm lead appears to have somehow either dissolved or vanished. So I'm in the process of plucking up courage to solder up a replacement.

I imagine most of these arms that may be still around have long lost the disc the set-up instructions mention for adjusting the stylus overhang (which wouldn't be possible, of course, with a 32mm diameter hole in the armboard!); if anyone is interested—or would like to make one— it was an aluminium disc 5mm thick and 35mm diameter with a central hole drilled for the turntable spindle.


You can get the silicon damping fluid from Michell dealers. Or probably direct from Borehamwood if you ask nicely?