G86 boring

[Derek]

Tested out the G86 bore cycle. I believe G86 is supposed to stop the spindle at the bottom of the hole and then rapid out. It then starts the spindle again in what ever direction it was going. Right now it is just feed in rapid out with no spindle control.

G85 works as expected.

Thanks
Derek

[cncdrive]

Hi Derek,

I verified the G86 and it works now how we wanted it to work. From what I read what I understand is that the G86 only switches the spindle off at the bottom of the hole and switches it back on when it retracted and reached the retract point which is the end of the G86 cycle. The G86 does not switch the spindle on at the beginning, you have to take care of switching the spindle on if you want with a M3 or M4 before the G86.
Then the G86 cycle checks if the spindle is on with M3 or M4 and then it switches the spindle off at the bottom of the drill and it remembers if the spindle was originally running with M3 or M4 and it switches the spindle back on the same direction that it was originally running M3 or M4 when the tool retracted and the G86 cycle finished.
So, I see no mention in any documentation that the G86 should switch the spindle on on the beginning, all documents what I found so far only describes that the spindle has to be stopped at the bottom of the drill and has to be switched back on at the end of the G86 cycle.
Please let me know if there is any documents you know which describes elseway.

[Derek]

Hi Balazs.
Sorry I wasn't too clear. My spindle does not shut off at the bottom of the hole. It just rapids out. There may be something I'm missing in the gcode. I really don't use G86 but I thought on some reaming applications it may be nice.

[cncdrive]

Hi Derek,

Hmm, that's interesting, because the spindle off and on are in the code and when I tested it earlier and also I tested it now then it switched off/on.
It is basicly calling the M5 and later the M3 or M4 macros.
Are you sure it does not switch your spindle off and on? Could you please verify it again.
And if you verify that also please check if the M3 button's virtual LED goes off/on or not?

[Derek]

My bad:)

I don't have a spindle off delay on. It works as it should. I added a P2000 and it worked great. The only thing I don't like about G86 is it rapids out of the hole. That's the nature of the beast I guess.

[cncdrive]

OK.

What I found docs all describes that it should do a rapid on the pullout.
But I could add a new parameter if you want which could define to rapid or feed out, like with the G84 H direction parameter.
If the parameter is not defined then it could work as the standard G86 with rapid and if the parameter is defined then it could feed out instead of rapid.
What do you think?

[Derek]

That would be great.

It seems weird that the standard is rapid because to me it seems like a rapid out is going to make more of a burr. I'm just guessing though.

[cncdrive]

OK, I will add the mentioned parameter.
Yes, it's strange to me too that it is rapid, but all docs say so, e.g.:
http://www.helmancnc.com/g86-boring-cyc ... ogramming/
And I have several PDFs for different controls and all documents say that the pullout is rapid.

[cncdrive]

H parameter was added ... will be in the next release.