Re: Re: My CNC Mill retrofit project

Andrew Werby wrote:

> I think the relay (CR2)
> labeled MAN. TOOL CHANGE is probably just for a tool change light or beacon.
>
> [Does this turn the machine off in the middle of an operation, so one can
> change tools and resume?]

Not exactly. Other commands in the program would bring the machine to a
stop, and position the spindle (if equipped for spindle Z motion) at full up.
Perhaps the tool change command puts the CNC in a wait condition, and
either a continue key or a switch closure from the tool changer tells it to
continue.

> My big question is what are the characteristics of the interface to the
> Lovejoy spindle drive.

Well, the spindle drive probably gets power whenever the machine is out
of E-stop, and the speed would be programmed by either +/- 10 Volts
(more common with DC servos) or a contact closure for each direction and
0 to +10 Volts for AC drives. Might also be a spindle brake signal, and
a spindle ready signal going back to the CNC. You should also check to
see if there is a spindle encoder.

> [I thought that was the most straightforward connection of the lot- isn't
> it hooked directly to 3 phase 220 (after the fuses)? Then there seems to
> be a 5amp(max ) 110 volt control circuit to change the speed and a spindle
> error opto , as well as 2 optos for spindle CW and CCW. But now, looking
> at it more closely, it seems like there was a modification made, because a
> new spindle speed board is drawn in by hand on my schematic, coming from 92
> on the terminal block. I'm not sure how this corresponds with reality,
> though.]

Hmmm, a little hard to say, but a variable speed command signal would be
most useful.

Jon