tailstock traverse pin limit switch

[axis overtravel]

hi all

re: daewoo puma 350m /fanuc 18t

does anyone know if the microswitch for the tailstock traverse pin is set normally open or normally closed?

i have just replaced the missing switch with a new one, exactly as specified in the machine manual, and wired it normally open, as this seemed the logical choice to me. [ i am by the way, not an electrician ]

however, the first time the traverse pin was extended in program, the machine alarmed out, even stopping the hydraulic power pack. this has made me wonder if i should have wired it normally closed.

any information would be greatly appreciated

regards

axis

[dcoupar]

I don't have an electrical diagram for that model, but a 400M shows the switch normally open. What is your machine serial number? What alarm did you get when extending the pin? Shutting down the hydraulics sounds like something other than having the switch wired NO when it should be NC...

[axis overtravel]

hi dcoupar

thanx for your reply.

i did not get an alarm number. the machine went into an e-stop state and i had to powerdown and completely reboot it.

the microswitch had been removed at sometime in the past, and the connecting wires taped over, but not together, so i figured the condition was 'open' hence i wired the switch that way.

i don't have the serial number to hand, but the fact that the machine alarmed as soon as the microswitch was operated suggested to me that the switch wiring may be incorrect.

of course there may be another fault entirely, which could explain why the switch had been removed. the tailstock/quill/traverse pin all work fine in manual mode.

i am trying to use macro programs to enable tailstock forward/home etc from within the part program. very slow progress when one is fairly novice in this area of endeavour.

when i issued the m code to return the tailstock to the home position, the saddle moved to the correct position to pick up the tailstock, then alarmed when the traverse pin deployed.

the only other time i had the hydraulics turn off like that, was when i was trying to mill a pocket on the end face of a bar. this was something to do with the feedrate going outside of the machine's range as the tool got nearer the center. oops!

thinking back to when i first started with the macros, it was how i found out the switch was missing. the traverse pin extended, but the machine timed out, as no signal had been received within, i think, 15 seconds. having had a similar problem with the quill, and having fixed that problem by adjusting the stop on the quill so it made contact with the switch, i removed the cover of the traverse pin, to find the switch missing...

regards

axis

[MysticMonkey]

I find it very strange the machine went into e-stop.

I would hazard a guess you have a 24v short.

But you need to supply the alarm number

is your machine an 18T or an 18iT.

[axis overtravel]

hi guys

no alarm number shown. just an e-stop. the control is an 18T

happened several times today, as i was developing the program to automatically position the tailstock, without using the macros.

i suspect the cause to be the traverse pin not being in correct alignment with the slot when activated, but when running the program with the doors closed it is rather hard to see what's happening.

i produced a quick program that does nothing exept move the tailstock from home position to user position and back, and this ran succesfully, so i included the routine in the part program. so far, so good.

when i get time [yeah, right!] i'll try the macros again.

best regards

axis