Delta 31 Instruction Manual page 13

ADJUSTING THE PLATEN
The platen (A) Fig. 24, is set at the factory 1/32 of an inch
higher than the crown of the drums (B). This allows the
belt, when properly tensioned, to lay flat on the platen
and eliminate stretching and bulging which might occur
if the platen is not at the right height.
When using the machine with a loose belt for
"strapping," the platen is removed and replaced as
follows:
DISCONNECT MACHINE FROM POWER
SOURCE.
1. Remove the side cover and top idler drum guard.
2. Remove the three screws (C) Fig. 26, that attach the
platen to the machine and remove the platen.
3. When replacing the platen, attach it to the machine
with the three screws (C) Fig. 26. Do not tighten the three
screws.
4. Using a straight edge (D) adjust the platen (A) Fig. 26,
so it is 1/32" higher than the crown of the drums (B),
and tighten the three screws (C).
ABRASIVE BELTS & DISCS - THEIR SELECTION AND USE
Delta supplies a wide range of belts and discs for use on your Belt and Disc Finishing Machine. These belts and discs
are recommended for a wide range of work on wood, metals, plastics and other materials. However, when a large
amount of production work of one kind is to be done, it is best to call in a coated abrasive specialist for specific belt
and disc recommendations.
All materials may be worked on a dry belt or disc. But for professional quality or for production work a low melting point
grease should be used for cooler cutting, better finish, and for longer belt life. Even coarse belts will "load" when
grinding aluminum dry, and so a lubricant should always be used for this material. To a varying degree, this is true of
other non-ferrous metals like soft brass and zinc.
A grease stick is often applied to the belt or disc to prevent "loading" of the belt on softer materials especially
aluminum. When grinding steel or some kinds of plastic, the grease stick is often used to prevent over-heating of the
work piece. Many times a single belt is used for both stock removal and for finish, just by lubricating one half of the
belt with light grease for stock removal and the other side or half of the belt with a heavy grease for polishing to bring
out a good finish. This can be done only when the parts are very small and need not be moved across the face of the
belt.
When an abrasive belt smaller than 6" is desired, the 6" belt can be split. This can be done by turning the belt inside
out and with a knife or other sharp instrument cut a slot in the belt at the desired width. Then proceed to tear the belt.
ONLY TEAR THE BELT A FEW INCHES AT A TIME ONE WAY THEN REVERSE THE TEARING
ACTION. THIS METHOD WILL REDUCE THE TENDENCY OF THE BELT TO UNRAVEL.
For certain applications, a mist coolant attachment (not supplied by Delta) will be helpful. If the use of a mist coolant
causes the Abrasive Belt to slip on the lower drive pulley, this can be corrected by using a "tire" which can be
homemade by wrapping the pulley with a piece of coated abrasive belt. The grit is, of course, turned to the outside and
cement should be used sparingly to avoid lumps under the "tire."
C
13
B
D
A
B
Fig. 26