Fusion Manufacture
Talk shop with the Fusion (formerly Fusion 360) Manufacture Community. Share tool strategies, tips, get advice and solve problems together with the best minds in the industry.
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Manufacturing two parts that are the same diameter are ending up with different circumferences

Message 1 of 3
90 Views, 2 Replies

Manufacturing two parts that are the same diameter are ending up with different circumferences

I have created 2 parts that are to be used as a mold for plastic injection machine.  Both of the parts consist of a circle 100mm across.

I generated tool paths and exported them to use with my CNC machine.  After milling the parts, one of them is 99.5mm across and the other is 102.4mm.  I have tried milling the molds twice and the diameters are the same so that indicates that it is the code that is the issue.

One of the molds is using 3d contour as a finishing pass on the mold (as it has a gutter with fillets around the perimeter of the mold) and the tool is a 1.75mm ball end mill.  The other mold has 3d flat as the finishing pass and a 4mm end mill.  I thought that maybe one of them had "Tool center on boundary" for Tool Containment but they are both set to "Tool inside boundary".

Can anyone suggest why I am getting different results when I mill these two parts?

Message 2 of 3
in reply to: psychochook

What is your machine and controller? Neither of those toolpaths would be my first choice for finishing something that could be handled much better with, for example, a 2D Contour toolpath using Cutter Compensation.

Seth Madore
Customer Advocacy Manager - Manufacturing
Message 3 of 3
in reply to: seth.madore

I have a QB2 with nighthawk controller -


I am still fairly new to Fusion360.  I will have a look at Cutter Compensation and creating tool paths with 2d contour to see how that looks.


Thanks for the suggestion.

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Autodesk Design & Make Report