Re: [CAD_CAM_EDM_DRO] Re: Auto tool changers

Actually, for semiautomatic CNC control of the tool changer, all you need is
to move the part to a position where it's out of the way. You wouldn't even
need to move to a special spot. Just raise the spindle to it's maximum up
position and insert at pause in the CNC program. Use a selector switch to
choose the tool and hit the go button for the tool changer. Optionally, you
could manually change tools using quick change tool holders.

For full CNC operation, you' might want to do something like Ballendo
suggested...use a few bits for selecting the tool number. With the tool
change command and the tool number, the tool is raised to max up position,
the program pauses and the tool changer operates when the up limit switch is
tripped. When tool change is complete, a signal is sent back to the program
to restart.

I've got the mechanism worked out on the DreamMachine. It was fairly simple
since mounting for it was allowed for in the initial design. The electrical
and mechanical controls can all be done with switches, relays and air
cylinders.

With the Bridgeport, I'll have to figure out some kind of mounting I can tie
rigidly to the machine. Perhaps I can built some sort of bracket that bolts
to the side of the machine or maybe to the horizontal dovetails on the
column. I would hope to use a similar design on the Bridgeport. This will
save some design work and might even allow some of the parts to be
interchangeable.


I haven't given any thought (yet) to an automatic tool changer for the
lathe. I think I'll let that slide until I get something built.

Smoke

> We do something similiar with a large Cushman pneumatic indexer on my
> biggest mill. Rather than go to the trouble of wiring this indexer
> to actuate by Mcode, we use a plastic tipped switch mounted on the
> mill table. To index, stop the spindle, move the tool tip over the
> switch, depress switch with tool, rapid away and turn on spindle.
>
> BTW, Smoke, automatically selecting the carousel to correct tool
> seems easy on a mill in comparison to the issues involved in actual
> tool change operation. What are your thoughts on achieving the tool
> change?
>
> Doug