Cloned: Kinematically correct roller chain sprocket generator

I was able to clone the original thread from the “History” of the one I accidentally deleted while accessing it from my mobile phone (fat finger syndrome … :sob:):

I got inspired by @jrlazz 's bicycle chain animation and thought I’d give it a try, too.
In its current stage, it only generates kinematically correct sprockets - no chain and no movement.

The sprocket contour comprises exclusively circular arcs and is computed on-the-fly, no pre-computed shapes are involved.

Instead of many words, a few screenshots and a Codepen:

Initially I’m starting with a 5-tooth sprocket for easier illustration (the angles involved are most pronounced). Disclaimer: in serious mechanical engineering, the use of sprockets having < 19 teeth is discouraged, except for “special applications”. Fun fact: my stock DUCATI Monster 1200S comes with a sprocket having 15 teeth. That’s why my bike probably doesn’t count as a “serious” machine …

Development disclosure:
Strictly NO AI was involved in this demonstrator’s development

7 Likes

Well when you finish writing this comment probably AI already grabbed your work, is a greedy monster.

We need to work with it, personally my production increased a lot since AI

It certainly feels better when it’s me feeding the AI, than the other way around 8-p

2 Likes

I don’t think you should care about this and embrace AI, you can’t swim against the current, is best to get used to it because is here to stay.

Maybe so. Besides, I’m not swimming against the current - I’m propelling it :wink:

2 Likes

Good one :slight_smile:

I completely understand but AI makes my production rate 80% faster no more googleing and brain burn reading and searching it gets you 90% there and no it will not replace me… is just a really cool tool this days that makes everything easier, I just hope we will not have a terminator scenario :slight_smile:

2 Likes

From an outsider like me it looks like it is not AI helping you to build something, it is actually you helping AI to build something… And at some point AI will not need you.

2 Likes

Who knows at this point but personally I find it extremely useful, it makes 99%of mistakes but it gets me where I want in no time I found it most useful for complex math, that would take me a lto of the tie with Ai is instan…

What I know is that we have to flow with it otherwise we will be left behind

Back to the thread’s topic:

I re-arranged the internal loops such that the arcs are drawn in proper sequence and as part of a THREE.Shape, which I extruded into a THREE.ExtrudeGeometry().
The updated Codepen logs the corresponding contour as SVG code for further processing i.e. in Blender. Depending on the browser used, you may have to edit the console log, like stripping unwanted empty lines and/or stray double quotes. Enjoy!

3 Likes

To round this off:

I’ve added code to draw a matching roller chain link plate, so all assets for a roller chain / sprocket rendering are in one place. The SVG code for the plate is also logged to the console.
Extended CodePen

If you import the outline into Blender (or comparable) and add a little effort, you may end up with something like this:


Sprocket_fancy15.glb (415.9 KB)

5 Likes

That is a beautiful sprocket.

1 Like

Thanks :+1:
I had a template. This is a fairly common after-market sprocket.

Try the attached .glb file in a glTF Viewer to enjoy it some more