Harrison Labs M400, Operation Manual

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(A) METRIC THREADS on METH.IC LEADSCREW MACHiNES
or
ENGLISH THREADS on ENGLISH LEADSCREW MACHINES
For these threads it is recommended that the "thread indicator
dial" be used·- this allows the leadscrew nuts to be disengaged
at the end of each screwc;utti ng pass, provided that the\.
re-engaged in accordance with the chart mounted on +h,
face of the dial unit.
METRIC LEADSCREW MACHINES
(METRIC THREADS ONLY)
The chart shows: -
in column 1. mm pitch to be cut.
in column 2. (•l The number of teeth in the 'pick-off gear'
arranged to mesh with the leadscrew, (this
being selected from the stack, stored on
the bottom of the dial spindle).
in column 3.
The dial numbers at which the leadscrew
nuts may be engaged.
ENGLISH LEADSCREW MACHINES
(ENGLISH TH READS ONLY}
The chart shows: -
in column 1.
in column 2.
T.P.I. to _be cut.
Dial numbers at which the leadscrew nuts
may be engaged.
(B) ENGLISH THREADS on METRIC LEADSCREW MACHINES
or
METRIC THREADS on ENGLI SH LEADSCREW MACHINES
�---�-....._.....�-
Ollll)mm
•
·225 18 15
4
16 1-8
25 16 1-8 4-5 18 15
.75 16 1-8 5
20 1357
1 16 1-8
5·5
22 15
1·25 20 1357
6
16 1-8
16 1-8 7 14 15
Hi'
16 1357 8 16 1357
1 ·75 14 15 9 18 15
2
16 1-8 10
20 1357
2·5
20 1357 1l 22 15
16 1-8
12
16 H
H
14 15
14
14 15
812
[lIIIDins
2 1-8
8
1-8 22 1-8
2½ l 5
9 1357 24 1-8
2! !
10 1-8
26
. l -8
3
1357 l1 1357 27 13S 7
3¼ l
114 15
28
J .. g
Jl 15
12 1-8
JO
1-8
4 1-8
13 1357 32 1-8
4; 15 14.
1-8
36
1-8
1357 16 !-8 40 1-8
6
1-8 18
1-8
44
1-8
7 1357
19
1357
48
1-8
7} 15
20
1.--8
56 1-8
813
For these threads the leadscrew nuts are kept engaged throughdut the cutting of any one thread.
This involves reversing the whole drive by means of the 'spindle control lever' (24) at each end of
the screwcutting pass whilst at the.same time relieving or increasing the cut as required.
(Threads 'A' may also be cut by this method).
Thread-cutting dial
21