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5th axis post help


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So we just bought a Yasda YBMVi40.  I'm trying to get the axis combinations sorted out but the closes I can get is either the -B- axis is off -90. or if I get the -B- and -C- correct then the -Y- and -X- axis's are swapped.  Any help would be great. 

This is what I currently have

#Primary axis angle description (in machine base terms)
#With nutating (mtype 3-5) the nutating axis must be the XY plane
rotaxis1$ = vecx  #Zero
rotdir1$  = vecy  #Direction

#Secondary axis angle description (in machine base terms)
#With nutating (mtype 3-5) the nutating axis and this plane normal
#are aligned to calculate the secondary angle
rotaxis2$ = vecx  #Zero
rotdir2$  = -vecz  #Direction

 

With this everything is correct except my -B- axis comes out B-3. and it should be B87.

 

Here is our machine at ZERO

 

YASDA-Axis.thumb.jpg.70568b82dc91a9ac1682a315a360d9d4.jpg

 

I have modified many other 5 axis machines with no issue. Not sure why this one is giving me fits. 

 

Thanks all

 

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First, make sure your test Tool Paths have for MI9$ and MI10$ values of '0'.

Be sure the following are set to Zero:

pang_output  : 0     #Angle output options, primary
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

Once that is set, if the Tool Planes are configured properly (always have to mention this, because Garbage In = Garbage Out...), then it will be one of the 16 following combinations of settings. These 16 different "settings groups" can further be subdivided based on the 'Tilt Axis Direction' (positive or negative.)

For a "B-Axis" Secondary (Tilt) on a Trunnion Table,  you should have either:

rotaxis2$ = vecz  #Zero        
rotdir2$  = vecx  #Direction 

OR:

rotaxis2$ = vecz  #Zero        
rotdir2$  = -vecx  #Direction 

Notice there is no "Y-Axis" in the Secondary Axis, so this means we "rotate about the missing axis vector".

You should either have a "-vecx" or a "vecx" value for the 'rotdir2$' variable.

So, based on that, you only have 8 different combinations of "Primary Axis Zero's and Directions" to try:

(I would try all 4 combinations with 'vecx', and all 4 combinations with 'vecy' as 'rotaxis1$', so you can get a feel for what these are doing:

Option 1:

#Primary axis angle description (in machine base terms)
#With nutating (mtype 3-5) the nutating axis must be the XY plane
rotaxis1$ = vecy  #Zero       
rotdir1$  = vecx  #Direction  

Option 2:

#Primary axis angle description (in machine base terms)
#With nutating (mtype 3-5) the nutating axis must be the XY plane
rotaxis1$ = vecy  #Zero       
rotdir1$  = -vecx  #Direction  

Option 3:

#Primary axis angle description (in machine base terms)
#With nutating (mtype 3-5) the nutating axis must be the XY plane
rotaxis1$ = -vecy  #Zero       
rotdir1$  = vecx  #Direction  

Option 4:

#Primary axis angle description (in machine base terms)
#With nutating (mtype 3-5) the nutating axis must be the XY plane
rotaxis1$ = -vecy  #Zero       
rotdir1$  = -vecx  #Direction  

Option 5:

#Primary axis angle description (in machine base terms)
#With nutating (mtype 3-5) the nutating axis must be the XY plane
rotaxis1$ = vecx  #Zero       
rotdir1$  = vecy  #Direction  

Option 6:

#Primary axis angle description (in machine base terms)
#With nutating (mtype 3-5) the nutating axis must be the XY plane
rotaxis1$ = vecx  #Zero       
rotdir1$  = -vecy  #Direction  

Option 7:

#Primary axis angle description (in machine base terms)
#With nutating (mtype 3-5) the nutating axis must be the XY plane
rotaxis1$ = -vecx  #Zero       
rotdir1$  = vecy  #Direction  

Option 8:

#Primary axis angle description (in machine base terms)
#With nutating (mtype 3-5) the nutating axis must be the XY plane
rotaxis1$ = -vecx  #Zero       
rotdir1$  = -vecy  #Direction  

 

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I think your biggest issue might have been not using 'vecz' as the Secondary Axis Zero.

For Gantry Machines, we think of the Tool Vector, (either NCI gcode 11, or the Z-Axis Toolplane Vector) moving, relative to the part.

For Trunnion Machines, it is essentially "backwards" from calculating Tool Tip motion. (What I'm describing here is not "changes to how you configure the setup", but how the internal Vector and Matrix Math Functions are executed, which just means you should think about the order of calculations in the reverse order on a Trunnion Setup.) To further complicate the setup, there is a 'switch variable', which allows the Secondary Axis to "flip the primary 180 degrees", when the Secondary Axis travel limit is tripped. This 'adj_2_sec' switch can also influence the output of the Post.

My test for Posts is dead simple. I believe that if you can't get "dead simple" to work, then you should not ratchet up the complexity before solving the easy stuff.

I test a Post by setting up my WCS to be the System Top Plane, then create my first Toolplane as "I want to rotate the Tilt Axis 90 degrees, without moving the Platter. So the first Plane on your setup would just output C0. with either "B90.", or "B-90.". Then I create planes to rotate from B90. C0. (1st plane), to the 2nd Toolplane. This should kick out B90. C90. The next Plane would be B90. C180., followed by B90. C270.

I also setup a 4" Diameter Arc, 4 Inches off the Trunnion Table (in Mastercam). I make sure the Arc is rotated (or start/end angles adjusted), so the Endpoint of the Arc is at the Primary Axis Zero vector. 

I Transform or Project the 4" Dia Arc to Z3. And Z5. (Three Arcs total.)

Then I create a Ruled Surface between the upper and lower arcs.

I create a 5-Axis Curve path, with the middle Arc as my drive curve.

I set the Tool Axis Control method to "surface", and pick the cylinder. Then I set the "collision control" to be surface, and set the Projection Type to be "normal".

The idea is to create a simple 5X Vector path which flips the Secondary Axis 90 degrees at the start, then cuts a 360 degree circle around the Platter, then retracts.

 

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8 hours ago, Colin Gilchrist said:

I think your biggest issue might have been not using 'vecz' as the Secondary Axis Zero.

You nailed it. I flipped the rotaxis2$ from vecx to vecz and everything seems to work.  Now I will go through and do a more extensive testing. 

Thanks for the great info. 

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