[OpenSCAD] Engineering Fits and Tolerance

adrianv avm4 at cornell.edu
Tue Oct 29 19:07:35 EDT 2019

Well, if it's supposed to be like a screw thread tolerance then the letter
specifies a "tolerance position", which gives a maximum diameter for the
bolt shaft.  The number gives the tolerance range below this maximum.  One
could imagine using this to shrink models to compensate for overextrusion. 
But this is a specific standard for machine screw threads and the value of
the tolerance even depends on the screw shaft diameter.   It doesn't apply
broadly to arbitrary objects.  (It doesn't even apply to nuts, which use
capital letters.)  

Even if you could figure out how to define it for arbitrary objects, how
would OpenSCAD know whether a component needed to be enlarged or shrunk?  I
don't see that there's any way to do this automatically.  

nophead wrote
> Not sure I understand. h7 specifies a tolerance, i.e. a range of possible
> sizes that can be tested with a limit gauge or a micrometer. How can that
> be expressed in a model, which always has a definite size?
> On Tue, 29 Oct 2019 at 22:00, Hugo Jackson <

> hugo@

> > wrote:
>> Has any thought been given to incorporating engineering fits and
>> tolerances into OpenSCAD? As I understand it, OpenSCAD was originally
>> conceived for the creation of STL files for a 3D printer and I’ve been
>> thinking that the base functionality might be improved by a little more
>> CAM
>> in the CAD.

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