Trigger Force

[ag1979]

Has anyone used, or does anyone use a gram gauge to set the proper triggering speed. And does anyone know a good way to figure out the optimum trigger force.

[Matthew D. Hoedeman]

One of the methods WE used to use, waaaaayyyyyy back in pre-history, was to take a piece of 0.001" feeler stock (the stuff that is 1/2" wide) and cut a piece about 3 inches long. We would then place it on a flat plastic pedistal with about 1/3 of the piece hanging out in space. We would then drive the machine down in SLOW mode (so it's not all that fast) and we would set it so that it would trigger a hit BEFORE the piece of shim stock would start to lift up off the block. What the actual gram reading would be, I do not know, but a piece of that feeler stock didn't weight much at all.

As for the rest, well, it's really going to depend on the user / machine / speeds and length of tip involved. So, if you are moving FAST with a long TIP on a NEW machine (which are fast) you might need a higher trigger force as opposed to an old machine (slow already) moving slow with a short tip. Your actual results will vary depending on your current needs. This is where the force modules come in handy on the (I think) TP20 and TP200 (I still use a TP2).

[cmmguy]

Trigger force can only be set on TP2, TP6, and I guess the Leitz probe can control trigger force. With the TP20, 200, 7, SP25 and 600 - you can only control touch speed.

The best way would be to calibrate your tip(start with a baseline speed/force setting) and then measure a standard such as a XX ring gage. Compare measurement vs actual ring size. Adjust speed/force until the two converge.

This is especially important when using star probes(which i dispise). If you check groove width/locations(not diameters) you should use a gage block to confirm the accuracy of the push/pull measurement against another probe setup. I have seen >40 micron error with a TP20 on grooves

[Bill **********]

Renishaws stated triggering force for the old TP2 was 7 grams. I don't know what it should be for anything else. It's preset in the tP20s.

Bill

[george frick]

ON OUR ZEISS MACHINES THE TRIGGER FORCE IS SET @ .1 NEWTONS & THE OLD SCANNING HEAD WAS SET @ .05/.10 NEWTONS DEPENDING ON THE APPLICATION.