Fast Feed for rotary axis

Al_V · 2004-12-02 15:47:56

Cincinatti T35 A950.
If I feed the B-axis to cut, the "F" word is degrees per minute.
This can sometimes be over F1000. I get a fast feed error for this. How should I deal with this? I don't want to make the fast feed that high for obvious reaons.
Thanks

Kantha · 2004-12-02 16:36:48

I really do not know how to do what you are asking. As we have similar T35, I like to tell you how we do. We have set out post to switch to indirect when it encounters B cutting. This works good for us as we machine with B,X,Y and Z simultaneously. What do you do when you need to machine B with other axes? The indirect feed rate works good with vericut too.

Regards
Kantha

Al_V · 2004-12-02 16:42:29

I am not using inverse time feed (G93) when I feed B only.

G94 F word is degrees per minute, like F1080. 3 complete rev's in one minute.

Problem is Vericut reports this as material removed at fast feed.

Kantha · 2004-12-02 18:06:19

I understand that the G94 is inches per minute and when used with only angles, it is degrees per minute. I have dealt with this situation in two of our machines. These machines will take IPM (if it is linear axes) and deg/min (in case of rotations only). We had it like that. We used to calculate the degrees per minute and give that as feed rate. It was ok as long as we machined either with rotary or linear. When we had to machine with linear and rotary, we could not anything other than going for indirect.

Al_V · 2004-12-02 18:21:05

Kantha,

Thanks for trying to help, but I am not asking for help with my machine.

I am asking how to set a different fast feed in VERICUT to allow for the large numbers invloved in DPM, and still be able to catch a linear fast feed stock removal.

I do not change my programs to satisfy Vericut, but try to configure Vericut to behave like my machine does.

I use Inverse time feed just like you do, but I also use DPM.

If the machine can do it, Vericut probably can too.

BillH · 2004-12-09 02:14:06

Hi Al,
VERICUT can correctly calculate the per-minute feed rate of the tool tip, regardless of how you program it, if you configure the control correctly. Have a look in the help for the description of the FeedPerMinuteType macro. I think you should call it at the start of processing event. I think you want to use type #2.

Hopefully you know how to do this, since I didn't include the exact detailed steps.
Let me know if this fits what you want.
Bill

Al_V · 2004-12-09 12:49:13

Thanks Bill,
I got the same advice from Ely Wahbeh, and it does work.

vhubbard · 2005-01-05 15:25:32

Kantha wrote:

I understand that the G94 is inches per minute and when used with only angles, it is degrees per minute. I have dealt with this situation in two of our machines. These machines will take IPM (if it is linear axes) and deg/min (in case of rotations only). We had it like that. We used to calculate the degrees per minute and give that as feed rate. It was ok as long as we machined either with rotary or linear. When we had to machine with linear and rotary, we could not anything other than going for indirect.

We worked with CGTech to get the G94/IPM combined linear AND rotary motion time calculations working correctly.

Our posts calculate the feeds correctly for linear and rotary moves combined. You need to remember that Feed in MMpm/IPM is not really Inches or Degrees per minute, but scale units per minute. Time is calculated by a formula that treats each axis as units per minute. The formula is in many of the Fanuc machine programming manuals.

Inverse time was needed on many older controllers to reduce the number crunching load and help improve machine response. The problem is inverse time can be based in seconds on some machines or minutes on others. When based in minutes, roundoff causes actual feeds on small moves to vary greatly.

Al_V · 2005-01-05 16:04:07

vhubbard wrote:

You need to remember that Feed in MMpm/IPM is not really Inches or Degrees per minute, but scale units per minute. Time is calculated by a formula that treats each axis as units per minute. The formula is in many of the Fanuc machine programming manuals.

Actually, on this Cincinatti machine when you feed one rotary alone it IS degrees per minute, and this was the only case in point here.

VERICUT Users' Forum

#1 2004-12-02 15:47:56

Fast Feed for rotary axis

#2 2004-12-02 16:36:48

Re: Fast Feed for rotary axis

#3 2004-12-02 16:42:29

Re: Fast Feed for rotary axis

#4 2004-12-02 18:06:19

Re: Fast Feed for rotary axis

#5 2004-12-02 18:21:05

Re: Fast Feed for rotary axis

#6 2004-12-09 02:14:06

Re: Fast Feed for rotary axis

#7 2004-12-09 12:49:13

Re: Fast Feed for rotary axis

#8 2005-01-05 15:25:32

Re: Fast Feed for rotary axis

#9 2005-01-05 16:04:07

Re: Fast Feed for rotary axis

Board footer