[Geof]

The 3/8" drill broke about 4 minutes after I left

I have wondered about Rube Goldberging something together as a broken tool detector to prevent this sort of thing, especially with drills and taps.

I have seen systems advertised that use laser beams or probes whcih are not cheap but I wondered about a system with a microswitch operated by a little feeler. At the toolchange before, or after, position the turret so that as the tool change occurs the drill nudges the feeler and closes the microswitch to reset something.

I haven't entirely figured out the something but maybe the M-FIN function could be used:

If the drill is intact the microswitch closes momentarily and this would operate a relay wired to self latch in the M-FIN signal circuit.

Immediately after the tool change give the M-FIN code and use the M-FIN relay to close another relay in series with the latching relay.

If the drill is intact both relays are closed so the M-FIN signal circuit is closed, the machine continues and turns off the M-FIN relay which opens the M-FIN signal relay and the machine continues running the cycle.

The latching relay has to be reset and this could be from another user M relay:

Wire this relay in a normal closed configuration into the latching circuit and immiediately after the M-FIN code have the other user M code to open this relay dropping the latch out, then cancel this user M to reset everything for the next toolchange.


This should allow you to detect several different drills or taps by having the turret move into an appropriate position for each one and would also be adaptable to parting tools.

Total part count is one microswitch, two small relays and a low voltage power supply.