Hi Bas, I’ll look at your model soon. Just from your screen shots, it looks ok. I can see though that however you defined your module or diametral pitch (one is the inverse of the other), they are not conventional, because you have set the initial profile somewhere around the midway along the gear face.
I have inserted here the cut-down version of piece I wrote a couple of months ago on how module is conventionally defined for a bevel gear; starting with a few quotes.
Radzevich 2012, Dudley’s Handbook of Practical Gear Design and Manufacture: With regard to bevel gears “The specified size dimensions are given for the large end of the tooth. A bevel gear tooth that is 12 module at the large end may be only around 10 module at the small end.” (Page 26)
SDP/SI 2019, Elements of Metric Gear Technology : “Since bevel-tooth elements are tapered, tooth dimensions and pitch diameter are referenced to the outer end (heel).” (page T62)
Maitra 1994 Handbook of Gear Design, 2nd ed.: With regard to bevel gears, “The tooth data of a bevel gear are all given with reference to the large end[/color]”. (Section 5.1)
Oberg 1920 Spur and Bevel Gearing : “In speaking of the pitch of a bevel gear we always mean the pitch of the larger or outer ends of the teeth[/color]”. (page 202)
This convention has been in use for at least 100 years. All the stock gear manufacturers such as KHK and Boston Gear use the same convention in stating the module of their gears.
Actually, this convention is not arbitrary but is directly based on the basic concept of the bevel gear. As the excellent SDP/SI Elements of Metric Gear Technology explains, “Bevel gears have tapered elements because they are generated and operate, in theory, on the surface of a sphere. Pitch diameters of mating bevel gears belong to frusta of cones, as shown in Figure 8-2a.”. (The figure is worth looking at). So, the module is drawn on the surface of the theoretical sphere, which is the outer limit of the gears. That ‘back cone’, or ‘beveled back face’, which one sees at the ‘big end’ on bevel gears is a conical approximation of that spherical surface, and also intersects the pitch diameter.
In theory, the gears could mesh right to the centre of the sphere, but of course, they don’t. Where you cut off that inner end of the gear face is not theoretically established, but is a function of experiments with loading and so on. So you can’t set the module ‘midway’ along the gear face as a meaningful standard, because it would become dependent on the arbitrary choice of face width. And so, it is definite that the module, in bevel gear theory, is only located at the ‘large end’ of the gear wheel where everyone expects it and can find it very easily.
