MIL-P-80068D
3.4.1 Frame and base. The frame and base assembly shall be constructed
of either cast steel o r fabricated steel plate and shall be of sufficient
s t r e n g t h and rigidity to maintain original alignment without distortion of
the frame or workpiece while operating at maximum load condition. The frame
and base assembly shall have provisions f o r securing the positioner to a
mounting surface. T h e positioner s h a l l be provided with a ground block
located on the base or frame for the connection of an electrical ground cable.
3.4.2 Table. The workpiece t a b l e shall be constructed of either cast
iron or f a b r i c a t e d s t e e l p l a t e a n d s h a l l b e o f s u f f i c i e n t s t r e n g t h a n d
r i g i d i t y to maintain alignment without distortion of the table or workpiece
while operating a t maximum capacity load conditions. Unless
otherwise
specified (see 6.2), the table work surface shall be machined flat to within
of an inch. U n l e s s otherwise specified (see 6.2), the table shall be
either round or square shape arid be not less than the dimensions specified
herein.
All table operations shall be smooth and shall not show evidence of
galling or binding. R o t a t i o n shall be provided with stability and variability
shall be as specified herein.
T a b l e s shall be provided with four equally spaced
3.4.2.1 T-slots.
r a d i a l T-slot. The T-slots shall conform to ANSI B5.1 and shall be of the
s e l f - c l e a n i n g type. T-slot length on the square
t a b l e shall be not less
t h a n 80 percent of the diagonal dimension of the table. Tables shall be
provided with pilot holes and four matching T-nuts . When specified (see 6.2),
round tables shall be supplied with concentric c i r c l e s t o a s s i s t i n
positioning parts on the table. The concentric circles shall be scribed every
2 inches of the radius. When specified (see 6.2), square tables shall be
supplied with eight equally spaced T - s l o t s plus eight T-slots adjacent and
parallel to the table edges.
3 . 4 . 2 . 2 Spindle. When specified (see 6.2], a hollow spindle shall be
furnished on all p o s i t i o n e r s .
Spindle bearings shall be as required f o r
continuous performance and shall be protected from ground welding current.
The spindle taper and runout shall conform to ANSI B5.1O.
3.4.3 Table drive system. The table drive system shall be powered by a
variable speed, reversible, s i l i c o n controlled rectifier (SCR) type, direct
current (DC) drive system and a self-locking wormgear arrangement. Motors
shall be provided with magnetic or dynamic brakes and shall conform to the
requirements of 3.4.4.2. All positioners shall be provided with 360 degrees
of power table rotation. All gears shall be adjusted for minimum backlash of
.002 inch per inch of radius or less and, after adjustment, the gear case or
adjustment point s h a l l be secured to assure safety. Ground weld current
conduction for all positioner systems shall be not less than 500 amperes for
sizes 2 through 7 for class A positioners and not less than 1000 amperes f o r
s i z e s 8 through 16. Ground weld current conduction f o r a l l p o s i t i o n e r
bearings movement systems shall be not less than 500 amperes for all sizes of
class B positioners.
7
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business