Model Engineers’ Workshop – August 2019

August 2019 41

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Rotary Table

M

ark out for 4 bolt holes and drill

6mm, photo 17. Drop the brass

disc into the brake disc and using

a transfer punch mark the 4 holes onto the

steel disc, photo 18. Remove the steel disc,

drill 5mm and tap M6. If you look closely

at the photo you will see that the nearest

hole has been stamped with a number 1.

The corresponding hole on the brass disc

is likewise stamped with the number 1 to

ensure the parts are fi tted in the correct

position, photo 19. The parts are held

together with four cap screws. I originally

assembled it with four short lengths of

spring to apply pressure but leave the

table free enough to turn, photo 20. I later

changed the springs for spring washers as a

small amount of lift could be detected and

they worked much better, photo 21.

The rotary table can now be assembled

with plenty of oil, photo 22. Centre the

rotary table under the milling machine quill

with a centre in the brass disc, photo 23.

Then tighten the nuts that hold the base

plate to the milling machine table, photo

24. An indelible pen is used to write some
    information on the inside, photo 25. Move
    the milling machine table over and drill and
    tap four M6 holes, photo 26.
    Mark out an 11’’ circle on the piece of
    20mm thick MDF, photo 27, and cut out
    with a jigsaw. Finish the edge on the disc
    sander. Drill four 6mm holes to match
    the four holes tapped in the disc and
    countersink. Fix the MDF to the brake disc
    with four countersunk socket head screws.

19

20

Drill and tap the steel disc

Four short springs