Large bevel gear with tiny teeth

I have used GearGen written by Thomas Anagnostou with great success generating bevel gears up to about 24 in. in diameter. The design for the current iteration of the project requires a larger diameter bevel gear; the pitch diameter in the neighborhood of 51.20 inches while the face of the tooth is only 0.142 inches long. Can GearGen be modified to handle such a large diameter, small tooth design? If not, is there another script that can? The link below is to a quick and dirty representation of what I’m working on. (Note: I’ve edited the file since first post)


I don’t know of another gear generating script but you may find more traction on this in the Scripting category.

@pascal do you know of anything else in this area too?



Thanks, BrianJ, I’ll try that.


Ran across this looking for Gear Gen today, I have used it in the past and must have deleted it, your post is a little old but there is an answer.

You can modify the number of teeth in the script, The Author, Thomas Anagnostou has a limit of teeth and it is set at 400, and to be honest I am not sure why, if you could contact Thomas Anagnostou he may be able to tell you why. I have changed the 400 to 1400 ( it could be more) and have made laser cut rack segments on much larger diameters then this that work well with commercially made pinion gears. The 400 limit is only in 3 places in gear gen and starts around line 267 and ends at around line 271. This is my editing, and the 1400 is were 400 was when I first downloaded it. A tooth count of around 1000-1100 would give about the height you are looking for the circle you mention

								if (choice = every or choice = generic or choice = angles) then _
									SuggestDefault(angles) = array(array(14.5, 16, 1400), _
										array(20.0, 13, 1400), _ 
										array(-1, 7, 1400))

Just remember just about anything you do to a script can mess up its running. A period missing or a period in the wrong spot or comma added to a wrong spot will not let this run, So if your not a script writer it can take forever to figure out that you deleted a period someplace and didn’t even know it.

Hope this helps

1 Like

Outstanding! Thank you!

I received some guidance a while back which suggested that in order to minimize damage to a main bevel gear from a damaged tooth on a pinion bevel gear and vice-versa, that I should not make the gears have a ratio of whole numbers, i.e. 5 to 1, in my case.

I looked for the posts in this forum but didn’t see it so perhaps I got it from another source. It’s been over a year ago.

It was suggested that instead of designing the main bevel gear to have 180 teeth and the pinion 36 resulting in the desired 5-to-1 ratio, that I should design the main bevel gear to have, say, 181 teeth and the pinion 36 teeth. The reason given was that in the case of using a whole number ratio the same damaged tooth would arrive repeatedly at the same mating teeth, thereby causing the most damage to the mating gear.

I first generated a main bevel gear using Thomas Anagnostou’s script gearGen to have 181 teeth instead of 180 at the desired pitch diameter.
I then generated a pinion bevel gear with it’s pitch diameter at 1/5 that of the main gear to have 36 teeth and copied the options from the main gear, i.e. module, circPitch, etc., into the fields for the pinion gear. The script prompted for a choice between keeping the same number of teeth (36 in my case) or pitch diameter. I opted for keeping the 36 teeth.

After generating the pinion gear and lining the two gears up using points on their respective pitch diameters, I rotated the main gear about it’s center in order to mesh appropriately with the pinion. I then positioned the pinion pitch-circle to pitch-circle with the main gear. I then moved the pinion away from the main gear by 0.001 [in}, along the axis of the main gear to provide some clearance between them.
I performed Curve From Objects>Intersection to see if there were any interfering surfaces.
The result was that there were indeed interfering edges and surfaces.

I moved the pinion away again along the axis of rotation of the main gear and repeated the Curve From Objects>Intersection command and again it revealed areas of interference.

So, my question is: What’s the correct way to generate matching bevel gears having 45 degree cone angles using Thomas Anagnostou’s gearGen script? Should I just let gearGen pick the Module, etc., given the appropriate pitch diameter and number of teeth for the pinion gear?


My assumption that a 45 deg cone angle for both pinion and gear is wrong, evidently. I’m going to try this
and see how it works out.


The GearGen script can now be found --> here. I have removed the limit of 400 and bumped it up to 1000. Is that a more realistic number ?

1 Like

Thank you!