[xray34]

HI,

I had a recent problem with my Hurco VSX24 'Z' Axis
The control showed unexpected limit switch when I had my Z axis near the limit of its negative travel..
Then upon starting a new part the Z was about 0.6mm out of calibration...
So after a quick chat with the Hurco tech over the phone it was suggested that I check the couping bolts..
And to my horror all 4 where not tight !!!!!

So does anyone know the torque setting for theses bolts??
(see attached photos)
Many thanks...

[bloke]

Undo the set screw on the other side to the two M6 caps.
Tighten the two M6 caps just firm hand tight (don't go mad now. The coupling is a tight fit on the screw even without locking up - hence the set screw to open it up enough to slide it on). I don't know of any specific torque settings. When done, nip the set screw so it doesn't fall out.

[xray34]

Undo the set screw on the other side to the two M6 caps.
Tighten the two M6 caps just firm hand tight (don't go mad now. The coupling is a tight fit on the screw even without locking up - hence the set screw to open it up enough to slide it on). I don't know of any specific torque settings. When done, nip the set screw so it doesn't fall out.

Thanks bloke.. I will do in the morning.
I was (as I said before) gobsmacked that they where loose!!
I assume that the Z could fall (albeit slowly) under its own weight if this coupling came fully loose.
I believe that the brake only applies under power off.. is that correct?

Thanks again
:-)

[bloke]

They do grip quite tight on the shafts even when loose. It would drop if you were to loosen them and then pinch the set screws. As a side note, nip the top set of M6 screws first so the motor will hold it all secure for the bottom set. Put a piece of wood under the head if you aren't sure of what it'll do.

[xray34]

Thanks bloke, will do.
I think this forum is awesome, the best help anywhere..

:-)

[xray34]

They do grip quite tight on the shafts even when loose. It would drop if you were to loosen them and then pinch the set screws. As a side note, nip the top set of M6 screws first so the motor will hold it all secure for the bottom set. Put a piece of wood under the head if you aren't sure of what it'll do.

After loosening the grub screw I managed 2/3 of a turn on each bolt
by hand using a standard length allen key.
All seems well and I ran a 4 hour program with continuous and vigorous
small and large Z axis movements at high and low feedrates
Then I checked a calibrated tool several times
with a (Pro Touch Off Gauge)tool setter and found no errors.

Thanks again for your input bloke. :-)

[bloke]

No problem, fella!