Freecad

HI Tony,

On the left of the display should be a tree structure of the various primitive items that the beastie is composed of.  With 'the_guide' is a 'joined_guide' and in that is a 'fused_side_a' in which is a 'hollow_ear_a_bk.  The 'hollow_ear_a_bk' is made up of several items. An 'ear' with a radius of 5.1mm - this is the outer radius,  And then there is a 'to_cut_ear' made up of  a fusion of  'ear_in' which has a radius of 4.1mm and a block shape.  The to_cut_ear is subtracted from the 'ear'  to make the hollow for the ball to sit within. 

To allow it take a 9mm ball you need to change the radius of 'ear' from say 5.1 to 5.6mm and of 'ear-in' from 4.1 to 4.6mm.\

Remember you can toggle hidden things to be visible by pressing the space bar when the item is highlighted in the tree view. Below the tree view is the attributes of the entity - like its radius.  Just edit the number.  You might have to ask freeCAD to recompute 'the_guide' if the differences to not show up. Right click on 'the_guide' in the tree view and one of the options is to re-compute.  -Jon

Ah, if you want additional clarification - I can capture a few screen shots if that would help.

Klippy
I wonder if you are looking at the FreeCAD representation of the STL version of the file. The file you export to the slicer. You can do nothing with it in FreeCAD.
I do not recognise exactly what you have but this is as close as I can get in FreeCAD with one of my STL files. 
 
What you need to look at in FreeCAD is the FCSTD version of that file.
 
It allows you to edit the FreeCAD parts of the model.
 
You then save it, under a new name , then 'select all' and 'export' it as an STL file. This is what the slicer uses and converts into the code file that the printer understands.
I hope this helps rather than confuses.    
 

Tony, would this be a good time to try me viewing your screen?  I can have the same free cad file up on mine.

I could also use your comments - I tried to pair one of the Rx that you gave me with my Futaba and the transmitter seems reluctant to do its part.

If you want to try it then let me know.  B and I are off tomorrow morning for Svalbard....