In this tutorial we are going to look at how to animate a gear train in Blender with constraints, such that all the gears follow the lead of a single empty. This technique offers a much cleaner system with less margin for error
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- High resolution video – .mov/h.264
- .blend file at the state of the tutorial








hey dude
love the tutorial
but i have a problem i hope you can help me with
i have my rod on the vertical, i have the location values set correctly but the rod resets at 180 degrees rotation, what am i doing wrong
Check that you have the correct axis set for the constraint. The simplest way to do this is simply trial and error, try each one until it works (that’s the inaccurate, but simplest way).
The way you made the gears there is a gap between the cogs of the firs and the second gears. How do you make it move realisticly – the second gear shoud not move until it comes in contact with the next cog of the first?
I’m sure my question would be more along the lines of the game engine but maybe you can answer it. In your tutorial, all the gears act independantly from one another. I would like to see a more “Cause and Effect” set up where the rotation of the first gear causes the rotation of the second gear, and so on. The action between cause and effect would be the teeth on the first gear pushing the teeth on the second. Also, setting up some sort of limiting blocks to prevent overrotation. Is this possible.
This might be possible using Bullet physics through the Game Engine. It would probably be done using rigid body constraints for rotation. Hmmm… I will have to play with it.
I used this gear tutorial and then added a tank track array deformed by a curvecircle and transformed the location by the rotation of the empty (like you showed using the cube) and a simple tank tread was created with everything rotating together. Thanks for the very useful tutorial.
Really intriguing article, something comparable to this occurred to me not too long ago and it pretty much played out in the same way to how you describe it.
Hello Jonathan,
First of all, I would like to thank for the awesome tutorials that you have here on the website.
My question is quite similar to John’s question..
For instance, if i would making a robot, modeling, rigging, etc. Is it possible to make it’s junctions (like knees, elbows) to work properly? using riggid body or so..
My problem is that when I run the animation, all parts “explode”… flying to all sides.. I saw what John said about ‘limiting blocks’, and I’v tryed, but it doesent seems to solve the issue.
Could you give me some help ou advise.. something that i may have forgotten.
Do you think that just faking it would be a better way to carry on this idea?
Thanx a lot!
make links how made this=buttons to made make links please help thanks
Hey,
Great tutorial I made mine with a bigger gear. Only need to adjust the influence zone for the bigger one:
http://www.youtube.com/watch?v=nEoc3X1n0Ks
I think I can add a chain to this with ease.
Hey guys, i just tried that tutorial on blender 2.5 and it appears that the rotation constraint had a weird behavior.
I would say something about absolute value in the back-end code which make the object change rotation direction once half way.
Could someone else tell me if they have the same issues ?
tom.
same thin. when i rotate my empty to 90 deg the gears switch direction on 270 deg they switch again and so on
i found a work around. don’t check the rotation for other axies check box and it fixed mine
i’m using blender 2.5 alpha 2 and the transformation constraint won’t work :,-( the object just sits there >:-(
just read the 2 posts on top of yours
This video was very useful.Maybe I’ll try modelling an automaton from Syberia later.
Thx Jonathan!
thanks for the tut
I have a question: how to locate/rotate the gears so that they will never run into others when the Empty is roated.
I think this is not a question like chris has asked.
thanks again