where to install a tonearm


Hi, Until today I always thought that all that I need to set up a tonearm is to use a protractor to find the "pivot to splidle" distance and that's it. If I want I can draw an arc with this information and I can install it anywhere in that arc.
I have a Lustre GST-801 to install and in the manual found that besides showing you the correct distances, they include 2 more measurements: they draw a line that goes from the center pivot up to the point when it connects with the extension of the horizontal line of the spindle (basically where both lines meet in a 90 degrees angle). in the Lustre, those distances 199mm (horizontal) and 105mm (vertical). If I take this into consideration the arm will be too close to the platter (my TT has a peripherial ring) and that's not practical for me.
knowing that a platter is round I always though that we can install the arm anywhere in the arc line that I mentioned before ... am I correct?, am I wrong?, please help me with this, Im really confused.
jorsan
I just checked the manual on Vinyl Engine and;

Your arm has effective length of 240mm and overhang of 15mm, so mounting distance (pivot to spindle) is 240-15= 225mm.

You can put your tonearm around the platter wherever position you want as long as it is mounting hole center is 225mm from platter spindle.If you have a plinthless turntable and seperate arm pod your choice is wherever you want, if your turntable has a plinth you should choose a mounting place;
a-which is inside the borders of the plinth
b-if you usea any lid, care not to obstruct it's use
c-not too front because it increases the possibility of accidental stylus damage
d- aestethics

So, drill a hole 38-39mm diameter which it's center is 225mm from spindle then check the arm for 105mm. and 199mm which means the arm rest part will face at the right angle to front.I think these numbers are for the tonearm swiveling freely without any end stops over the record from beginning to end.

Good luck,
Hakan
Hi John, What about us? The most are right-handed so the
'normal' arm position is already determined by the TT
producers. Or should I say plinth producers? I have seldom
seen plinths with sufficient space for a tonearm on the
left side of the plinth.
So Jorsan if you are left-handed you are in trouble. That
is to say you need to order a special plinth by Vetterone
and those ain't cheap.
Hi Schubert (the family of?), You mean that the super
intelligent lefthanders adapt and improvise on the
right side of the plinth. There is namely no left side
to adapt to or improvise with. Except of course when the
plinth is turned around with the cover on the front side.