Proxxon UT 400 Manual page 12

For this purpose, there is a selection table in
the appendix that we can use to simply find the
dividing plate required for our pitch.
The respective columns and lines in the table
have the following meaning:
Meaning of the values in the selection table for
the dividing plate:
Column a: (desired) pitch to be created
Column b: corresponding "increment width" in
degrees (360° divided by the pitch)
Column c: required number of "full" crank rev-
olutions
Column d: additional holes required for making
the required pitch (with various di-
viding plates).
The various details from column d are also
allocated to the possible dividing plates in each
case: It may well be the case that the required
crank angle can be achieved with various
dividing plates with varying numbers of holes:
The required same angle can be formed with
different pitches of the dividing plate with a
different number of holes in each case.
So in our column a, we look for the value of the
desired pitch, e.g. "15". In the corresponding
line, the neighbouring column gives the value
of the degree scale, namely 24° per increment.
Alongside this is "2", this means "2 full revolu-
tions" then (also alongside it) 18 holes on the
27 plate (18 "additional" holes divided by 27
holes produces 0.666, the value that is still
lacking in the above equation for the 2 full rev-
olutions in order to achieve the increment we
need, taking account of the flange ratio).
Or, put another way:
3 holes on the 27 perforated disc correspond
to 1/9 revolution of the crank (i.e. one degree
of the flange, since 40x9=360, see above). 1/15
pitch corresponds to 24 degrees (15x24=360
degrees). We must therefore rotate the crank
24/9. I.e., 2 full revolutions and 18 holes on the
plate with 27 pitch.
– 12 –
We will use this example to show you how
to proceed in practice:
1. Find the desired pitch in the table and
select the corresponding dividing plate.
2. Use selected dividing plate where neces-
sary. To do this, see section: "Replacing the
dividing plates"
3. Fix the workpiece and bring it into the 0
position (starting position). Caution: Ensure
that the flange can rotate freely and is not
jammed.
4. Engage the crank pin in a hole on the
corresponding pitch circle.
5. Clamp the flange, and then carry out the
first machining operation.
6. Release the clamp.
7. Rotate the (upper) sector limiter (1, fig. 11)
in a clockwise direction until it stops at the
crank pin 3, which is still engaged.
8. Turn the lower sector limiter 2 by the num-
ber of additionally required holes (the table
value from column d) in a clockwise di -
rection. The upper sector limiter remains
against the engaged crank pin.
9. Pull out the crank pin and rotate the crank.
The position of the sector limiter 1 serves
as a marker for the original crank setting.
With its help, we can count off the com -
plete revolutions.
10. The sector limiter 2 marks the distance
corresponding to the additionally required
holes: these are, after all, "closed in" be-
tween the two sector limiters: We thus turn
the crank past the full revolutions (marked
by sector limiter 1) to the limit stop at sec-
tor limiter 2, and lock it there. So with the
crank, we have covered the desired num-
ber of full revolutions plus the required ad-
ditional holes.