Civil Engineering Reference
In-Depth Information
Fig. 7.5 This sequence shows you how to machine T-nuts. Machine faces A and B at
the same setting then rough out C and D. Measure the width over C and D. Raise the
table half the distance required to mill the tongue to size. Finish C, turn over and fin-
ish D at the same setting.
Pitch out the holes along the bar, drill and tap them. Finally hacksaw the bar
into individual tee nuts. Do not tap the T-nut right through, just leave a little bit
of the thread undersize. Then the studs will not screw right through the T-nut
but lock at the bottom of the thread. This will stop any tendency for the stud
to force the T-nut up in the T-slot, possibly damaging the table.
ACCURACY IN MACHINING
Basic technique
It is not difficult to machine work accurately to thickness on a milling machine;
it just needs a repeatable location to put the component in, and care used
while machining. Even for the relative beginner it is easy to work to the
nearest thousandth of an inch, as long as you have accurate measuring
equipment.
The secret is to tap the work down onto the parallel so it is flat. Do this
either with a copper mallet or put a bit of brass, copper or aluminium on top of
the component and tap it down with a hammer. Take a cut from the top of the
work, take the work out of the vice and measure it.
Then tap the component back down in the vice and take off the required
depth of cut (more than one cut is allowed) until the correct size is reached.
