Flow tool path problems with ball end mill

[brink.gregory]

The multi-axis flow strategy seems to be misbehaving when I use a ball end mill.  I have a model that works OK with a square end mill on a convex surface.  I'm about to move on to milling models with concave surfaces as well as convex so I changed the setup to try a ball end mill.  The 3D adaptive clearing operation seems to yield a similar result with the ball end mill as I had with the square end mill. 

When the cut file gets to the flow portion of the setup, the ball end mill cuts significantly below the surface.  At first I guessed that either the cam or the post was not compensating the effective point of the cut for the flow tilt feature.  Today I ran exactly the same strategy sequence with the only change being the tool selected and confirmed that flow process does does not seem to be correctly handling the ball end mill.part end viewModel end view

The left part in the top photo was machined with a 1/2" ball end mill with no tilt (Forward and Sideways tilt are both 0 degrees).  The part on the right was machined with a 1/2" square end mill.  Both tools are 2 flute, 4 inches long and installed so they have the exact same tool length.  The second picture shows the end view of the model for reference.

What can I try to debug the flow behavior when using a ball end mill?

I'm using a 5-axis shopbot.  I'm using a slightly customized version of the Shopbot openSBP (a few minor modifications to the post to get it to run better on my machine).

[johnswetz1982]

Does your controller have tool point control?

[brink.gregory]

No. It's the ShopBot controller running version 3.8.50 control software.

I ran the same machining sequence this morning changing the tool to a 1/2"
bull nose end mill with 0.060" corner radius. The results were very good.
It seems that the only problem is with the way the CAM handles the ball end
mill.

[brink.gregory]

I believe I've solved the problem.  I found the following section of code in the post:

  var tcp = properties.fiveAxis; // 4-axis adjusts for rotations, 5-axis does not
  if (tcp) {
  setRotation(W); // TCP mode
  } else {
  var O = machineConfiguration.getOrientation(abc);
  var R = machineConfiguration.getRemainingOrientation(abc, W);
  setRotation(R);
  }

I have a five axis machine so properties.fiveAxis was set to true.  I changed the line to:

   var tcp = false;

I changed the tool selection back to the ball end mill and posted.  The machine now appears to be correctly following the surface.