Awl--

Proly more inneresting to cadcamless muhfugguhs such as m'self, but mebbe
otherwise useful.

The Q is:
For a given 90 deg. V slot (eg, one V-slot in the back vise jaw), what is
the smallest rod that can be held in a V-slot (ie, too small a rod will
rattle), AND, what is largest rod that can be held by that same V slot (ie,
where the V slot walls will indeed hold the rod tangently and therefore
stable-ly, and not on the cusp of the V)?

Answer: ( d=depth of V slot; D=diam of rod )

D(small) = .829 d; D(large) = 2.828 d;
w/ the ratio of the large diameter to the small diameter being about 3.4.

Example:

Spose you want to hold a 1/8 rod horizontally in a vise jaw. You will need
to mill a V-slot no deeper than .151 deep.

Now, using the formula for D(large), the largest rod that can be stablely
held by this same V slot is max .427 diam. Or, just multiply the 1/8 rod
by the above 3.4 factor.

Probably, for 1/8 rod, you'd mill a V .135 deep, which would then limit your
large rod to about .375--still not a bad range.

Or so I think.

Now, what about iffin your V is not 90 deg? This is more of a pita, but
still do-able.

The formula becomes:
D(small) = 2d/(cos a + (sin a * tan a) + 1),

where the angle a is 90 - (included angle/2) of the V .

Or so I think.

Haven't gotten around to the D(large) for non-90 deg V's, cuz, well, my
vision is blurring and I got a bad sugar munchie attack.

Related to this is is *how high* a ball (radius = r) sits in a V-slot.
For a 90 deg V, a ball is raised by the amount .414 r .

For what it's all worth.
Iffin inyone is dyin to see the derivations, email me. Proly good SAT
practice'n'**** fer yer urchins.
----------------------------
Mr. P.V.'d
formerly Droll Troll