3.1 Foundation In general, the type of foundation adopted for motors depends largely
on the foundation planned for their individual drives, and no rigid rules can be
laid down apart from the obvious requirements that the foundations be strong and
rigid. Much helpful guidance may be obtained from IS:2974 Parts 1 to 4, code of
practice for design and construction of machine foundations.
3.2 Levelling Place the machine with its base plate or slide with the driven apparatus
and pack the space between the machine and the foundation with steel plates evenly
spaced 250 to 300 mm apart. Grout-in the holding-down bolts correctly and when the
mortar has set hard, level up the base plate by adding or removing steel packing
plates (shims).
Tighten the foundation bolts lightly at first, and carefully align the set with
the driven apparatus. Then tighten the bolts fully and check the alignment, rectify
if necessary. If machines surfaces are found to have warped, these should be leveled
with shims it is important that the above mentioned packing plates are situated
close to and on each side of every foundation bolt otherwise distortion of the base
plate will most certainly occur.
The foregoing applies to individual units as well as to large base plate mounted
complete sets, except that the latter are placed on machined flanges of heavy steel
I- sections which are themselves sunk upto the top flange in concrete foundation
to reinforce it and take the i-sections should be so positioned as to lie under
heavy load points.
Finally, cover the bottom if the base plate with 25mm thick layer of concrete extending
50mm from the base plate on all sides, using temporary wooden curbs for this purpose.