Need Help!- 4th Axis Lead/Lag Angle problem

[slideleft]

Hi All,
I seem to get A axis orientation issues any time I try to program Lead or Lag Angle using Rotary 4 Axis toolpath (cuts are off many degrees from my A zero). All works well when I program 0 angle. Any ideas??? Am I supposed to make an offsetting adjustment in my A offset?

I'm new to 4 axis, so a bit confused. Thanks for any help.

Jeff

Mastercam X

[slideleft]

Could it be because I am programming to tip of ball endmill instead of center?

[Superman]

Can you attach a session ( not pics ) to see what's going on ??

[slideleft]

Hi Superman,
What I figured out is that I programmed a +5 degree lead angle to tool, which essentially rotates A axis zero position 5 degrees (I think). Because part I am machining already has features on it that I need to register to, this is why my cuts were not coming in the right A positions. So I "thought" I only needed to subtract 5 degrees in my A offset, but for some reason this number is not quite enough (hard to determine what it should be). Any ideas??? I now know though that I need to maintain the lead angle in my operations unless I change offsets.
And...what is meant by session?

Thanks,
Jeff

[slideleft]

The best I can determine by measuring is that programming 5 degree lead = 9 degrees offset on part I cut. I'm baffled.

[HuFlungDung]

Can you post an informative picture of what you are trying to make? It sounds as though you've got features to cut that require moving the tool off axis in order to access them? Or is this a helical groove in the midst of other features?

[Superman]

Originally Posted by slideleft And...what is meant by session?

Hi Jeff
a session is just your mastercam file, delete all the operations that are OK for you, keeping the ones that are a problem ( just to cut down file size )

place this file into a compressed folder and then attach that folder to your next message ( use the paper-clip icon, browse your computer to select the folder and upload

[slideleft]

Here is jpeg. I put in 45 degree lead to exagerate my process. My problem restated- part is already shaped like object shown (3 axis milling). When I put any non-zero lead (+ or -), toolpaths lose registration with my A axis zero.

[slideleft]

Also, I need to add... its getting late here on west coast so I may not be able to quickly respond to any post. But.... thanks so much for having a stab at this.
Jeff

[Superman]

Looking at the pic

None of your tool axis lines are vertical ( pependicular to the A-axis centrelne )
this indicates that a 5th axis is needed to perfrom the tool motion

To be a path for use on a machine with an A-axis, those lines should only be in the XZ plane ie line endpoints cannot have differing X values

Your "Rotary Axis" settings are ON and the "Around X" selected, the operation parameters should also have the "4axis" button checked

[slideleft]

Hi Superman,
I can successfully cut with paths in XZ plane (tool directly over centerline) with my 4 axis if I put a zero Lead/lag angle. I was told ball endmills need a lead or lag to achieve a good surface finish. Programming this angle changes the Y position necessarily. But.... also messes up my clocking with the part.
Hopes this makes sense.
Jeff

[Superman]

I can successfully cut with paths in XZ plane (tool directly over centerline)

This is not the same.... think of rotating the actual tool in 3D space to get each of the "tool axis lines" vertical.
In programming...it is the tool that is being moved always, the part never moves.

so imagine these senarios::::
If you just need to tip forward and/or back, across the X axis ...then your toolpath is for a machine with it's 4th axis around X. The same method could be adapted to a horizontal machine with a B around Y.
If you need to also tilt the tool to the side any other other plane or rotate the model to enable tilting across the X-axis, then you have created a path only capable for a 5-axis machine.

Yes, you could use lead/lag on a 4-axis path...as long as it didn't go around a corner ( which turned it into 5 axis path )

Your post is only designed to output the additional A address.

FYI, you'll know if you have a 5-axis post, it is not cheap, and they are very customised to the machine and locked to a Sim.

I'd be very cautious about running that NC code...IMO it will not do what you think it should