5 axis post

[Rick Henrickson 65]

This is a 5 axis router and I am not familiar with this post. the head is A over C on the head. I notice that it will wind C -128 degrees instead of just going + 62 degrees which makes it have to unwind. is there someway to force shortest direction other than using the misc. int.

[Nils N]

Force the start of C into C+ or C- by selecting plus or minus for the router spindle starting position. This will help keep C from an unwanted unwinding.

[Jimmy Wakeford from Barefoot CNC]

what kinda router?

[Rick Henrickson 65]

cincinati old

[Jimmy Wakeford from Barefoot CNC]

If the post is old also look in the misc values to see if there is a switch for starting wound full neg or pos.

[Rick Henrickson 65]

yeah there is an MI for that

c axis preload

a axis preload

c axis bias

a axis bias

 

I just thought there might be some way to build the logic into the post, just like on a horizontal if you want to go B15.0 it doesn't go -345.0

[Jimmy Wakeford from Barefoot CNC]

I have been tinkering with logic that would automatically preload according to the toolpath.

The only success I have had is to buffer the entire path noting "flip" points and then starting accordingly. It does not play nice with the rest of post as you then have reread the path and call postblocks yourself. Also when updating some of the functions may have to be revamped so its easier to just pre-load in the misc page.

 

Maybe machine def will eventually do this for us.

[Rick Henrickson 65]

Thanks for the input, I am new to 5 axis but just wondered why it didnt react like horizontal 4 axis work. I know its more complicated for the post with the extra axis.

[Jimmy Wakeford from Barefoot CNC]

In the mpgen5ax series posts there is a variable for implied shortest distance. It works well, but sometimes you need to windup so you don't have to unwind in path.

 

Your post sounds like it is mpgen5ax based so you could make a copy of your post and tinker a little.

 

the vairable to tinker with:

sang_output : 0 #Angle output options, secondary

#0 = Normal angle output

#1 = Signed absolute output, 0 - 360

#2 = Implied shortest direction absolute output, 0 - 360