TM 9-3445-106-14&P
SECTION 3
B-18 and B-24 BACK GAUGE - INSTRUCTIONS
I.
Set up shear as per Shear Operating Instructions.
II
Loosen knurled lock screw on index plate next to handwheel. Turn handwheel until scale pointer (on R.H. bracket)
reads 1" and index points to "O" on handwheel. Tighten lock screw to hold handwheel in position. Insert stock in
machine, making sure it is squarely against gauge tee-bar for entire length of cut. Cut two pieces in this manner,
and measure the second piece cut for width and parallelism.
IIL
If piece is not parallel, loosen split collar at right hand end of connecting shaft between brackets. By turning
connecting shaft, move left hand end of back gauge bar in or out as needed. Tighten split collar and take a cut. If
still not parallel, repeat above.
IV.
If scale and handwheel do not show true width of piece as cut, proceed as follows after parallel setting is made
with handwheel at "0" and pointer at "1", cut a strip of stock and measure with a micrometer. Loosen 2 Socket
Head Cap Screwsat face of handwheel, as well as lock screw in index plate. Without moving back gauge, move
handwheel until proper setting as measured, is shown at index line. (Each division of the handwheel equals 1/128"
or .008") When measurement and handwheel reading coincide, tighten Socket Head Cap Screws on face of
handwheel. Move handwheel to reset back gauge for 1". Take another cut and check width of piece. Repeat
above if necessary.
V.
After width and parallel settings are made, adjust pointer by loosening screws holding it to R.H. gauge holder and
sliding pointer until it is right on either a "full inch" mark of a"l/2 inch" mark on the scale with handwheel at "zero".
Tighten pointer screws.
VI.
Back gauge is now ready to give long accurate service. Lubricate weekly all points provided with grease fittings,
with automobile chassis lubricant as well as oiling behind handwheel at frequent intervals.
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