Control feedrate with G93 active (Multiaxis)

[LaChaInSaW]

In Multiaxis mode with the G93 active, the feed is a little bit too fast but in linear (G94) it is ok because it's ajustable in the tool page.

I tried to play with the max. distance in cut pattern page but I don't know if it's the right way to do it ...

How do you control the feedrate in G93 ??

Mastercam 2017

Swarf Milling Feature

[huskermcdoogle]

G93 is time based.  Unless your post isn't calculating I would assume that there is something funny in your machine settings.  What is the maker and control type?  If it's a Fanuc we can certainly help diagnose the issue.

[LaChaInSaW]

I know G93 is time based...and my post is ok to run G93 on the machine HASS VF3 with Trunion.

I just want a know if my method is ok to ajust feed with Mastercam.

Tell me if i'm not clear enough.

[crazy^millman]

G93 is not controllable per say it is what you have programmed too. The difference you see if the post outputting the different values needed to make up for the distance from the pivot point of the 5 Axis to the contact point of the tool to the part. As that changes the feed rate will decrease in value, but increase the feed rate. The lower the value the more the feed rate will increase. This is why it is called inverse time. Problem is how is everything defined for the post to calculate everything correctly? People get worried when they see 99999 in inverse feed rate not realizing that is extremely slow and then they see 10 and think that is really slow when it is extremely fast. This feed rate is not liner feedrate it is Degree or arc feed rate depending on the machine. Where having a machine that does TCP is the best way, because then it does all the work of keeping the tool feeding the same feed rate through the whole toolpath motion. When a post has to do it then everything must be defined exactly as it is on the machine. Any difference and expect to see odd or even bad results.

[civiceg]

Is your work offset the center of rotation of the trunnion? This is a must for using inverse time on a table/table. 

 

The units for Inverse time is actually time. The whole premise is that you are using similar units of all axis, which is time. The other big factor in the calculation is how long the line length is from point A to B. 

 

Unit conversion for inverse time

 

Distance between point A and B / Feedrate =time 

Units for time             inches/ (inches/min)= min

 

Take the inverse of the time it takes from point a to b

1/time=inverse time feedrare

Units for inverse time             1/min=min^-1