Haas G76 Fine Boring Cycle - Spindle Direction

Hoppy · Feb 23, 2019

I'm using the G76 canned cycle with a left-hand boring tool that needs to spin counter-clockwise. At the beginning of the program segment I command S500 M04 and the spindle spins counter-clockwise, as you would expect. Two lines later when the control hits the G76 command, however, the spindle reverses and spins clockwise. How can I prevent the spindle from reversing?

sinha · Feb 24, 2019

I am not aware if it is possible. Perhaps not possible.

Till I read your post, I was under the impression that all milling cutters, except LH taps, are RH only, and work with CW spindle.

adama · Feb 24, 2019

S-500?

just a guess

thesidetalker · Feb 24, 2019

That's odd. Maybe it isn't supported by your control version?

It works on my NGC UMC750. Using a right-hand boring bar to finish the OD of a boss, spins backwards with M4.

litlerob1 · Feb 24, 2019

Why is a canned cycle needed to "feed in, feed out"?
R

precisionmetal · Feb 24, 2019

Hoppy said:
I'm using the G76 canned cycle with a left-hand boring tool that needs to spin counter-clockwise. At the beginning of the program segment I command S500 M04 and the spindle spins counter-clockwise, as you would expect. Two lines later when the control hits the G76 command, however, the spindle reverses and spins clockwise. How can I prevent the spindle from reversing?

Just out of curiosity: what's the line *between* your M04 line and your G76 line? Have you tried making the M04 line immediately preceding the G76 line?

guest · Feb 24, 2019

litlerob1 said:
Why is a canned cycle needed to "feed in, feed out"?
R

That cycle has a spindle orient at the top and bottom, a shift in X or Y to move the bar off the bore, and rapids back out.

The G76 line should restart the spindle the same direction as last command- M3 or M4. OP's program should be starting back up in M4, but it's defaulting to M3 for some reason.

It could be programmed to do that without the G76, if the machine was purchased with the "optional" M19.

I'd try what precisionmetal said- put the M4 line just before the G76 (but it's not supposed to matter)...

litlerob1 · Feb 24, 2019

guest said:
That cycle has a spindle orient at the top and bottom, a shift in X or Y to move the bar off the bore, and rapids back out.

That's pretty basic G-code IMHO.

R

guest · Feb 24, 2019

litlerob1 said:
That's pretty basic G-code IMHO.

R

Agree, and preferable to me to just write it out if it's just one hole. For multiple locations, G76 is modal so it would save writing it all out over again...

But on Haas, M19 is an option!

Search

Largest Manufacturing Technology Community on the Web

Search

Haas G76 Fine Boring Cycle - Spindle Direction

Hoppy

Cast Iron

sinha

Titanium

adama

Diamond

thesidetalker

Stainless

litlerob1

Diamond

precisionmetal

Stainless

guest

Guest

litlerob1

Diamond

guest

Guest

Similar threads