Civil Engineering Reference
In-Depth Information
Alternatively, turn a small pin to fit the rotary table at one end and the work
at the other end. If the pin needs to be removed - say to mill the hole in the
workpiece larger, and the hole in the workpiece is smaller than the hole in the
table - put a sleeve into the rotary table's hole to reduce the diameter smaller
than the hole in the work so the pin can be removed.
Say you want to mill a radius on the end of a bit of flat bar, but there is no
hole in it. Put a pin in the machine's spindle with a drilled disk the size of the
outside of the bar. Put the flat bar onto the rotary table and line up the work-
piece with the drilled disk and clamp it down. The bar can now have the radius
milled on it in the correct place, and you know that it will clean up.
If you have more than one workpiece to machine, you could set a side stop
ontherotarytable'ssurfacesoalloftheworkpiecescanbemilledatthesame
setting.
You can use this method to set up internal radii as well. Use the same pin
and disk method, but set the bar so the end that needs the internal radius
machined on it is just covered by the disk. Now you can machine the radius
knowing for sure that it will clean up.
There are many more ways that you can set work onto the rotary table; they
are only limited by your own imagination.
RADIAL WORK
Machining radial slots
Often you will be called on to machine a radial slot. This will usually be meas-
ured in degrees from the centre point at one end of the slot to the centre point
of the other end of the slot. I would drill the centres of each end of the slot
undersize first, making sure the angular movement was correct at each end.
Then I would finish the holes to the correct size using a slot drill, end mill or
boring head so the slot ends are correct to drawing. After that, I would remove
most of the waste material from the slot by drilling and then milling undersize.
I would then finally mill both sides of the slot to size using an undersize end
mill, one side of the slot at a time as discussed for straight slots.
