Pretty new to Blender and have been struggling with even getting this to work, but now it does. A big gear is parent to a smaller gear and, via drivers, I have them both spinning the same direction and at same speed. Thing is, I want the small one to spin about 3.5x faster than the big one. Of course, this is just part of my project, but one step at a time.

I followed the YT below as to how I got to this point. Start @ 2:44. I had to slow it down big time and pause it, rewind, etc. Days later, I'm to the point where I am trying to vary the smaller gear's rotation speed.


My big gear is 50t and smaller one 14, and I have a chain to connect them. My objective is to have it all in sync. In case it matters, its supposed to be a motorcycle chain and sprockets.


Here is one of my feeble attempts at getting the big gear to drive the little one. Rotate the axis in center...they both turn.

Dang it! I can't post a link with what I hoped the finished product would be like...but its like Paul's response..just my gears and a motorcycle chain.

  • $\begingroup$ I've made gear animation a while ago but I have used rigid body physics for it. Are you interested in such solution? $\endgroup$
    – cgslav
    Jan 20, 2017 at 1:20
  • $\begingroup$ I have no idea what 'rigid body physics' means, but maybe I can learn something from it. $\endgroup$
    – dmac1
    Jan 20, 2017 at 1:58
  • $\begingroup$ It's not so accurate simulation of dynamic bodies. I don't know a thing about cogs and gears so in my answer something might wobble or not work as expected. Also I need to try out version with a chain. $\endgroup$
    – cgslav
    Jan 20, 2017 at 2:01
  • $\begingroup$ Could you upload your blend file to: blend-exchange.giantcowfilms.com it will be easier for me to make an answer. $\endgroup$
    – cgslav
    Jan 20, 2017 at 2:05
  • $\begingroup$ A rigid body is a solid object that doesn't deform. And rigid body physics in blender simply means that blender simulates the dynamics of such objects, meaning that it calculates their movements and interactions, so you don't have to manually keyframe it or write drivers. Rigid body on Wikipedia is a fairly easy-to-understand explanation of rigid bodies in general, and blender's online manual has a section on rigid body simulations in blender. $\endgroup$
    – user27640
    Jan 20, 2017 at 2:12

1 Answer 1


Use a Generator Modifier for your driven smaller wheel. enter image description here

Select the smaller wheel, go to the driver's properties shelf (N) and add the modifier. Increase the value pictured below. Now the wheels are spining with a different speed. enter image description here

  • $\begingroup$ Wow Paul...thats pretty much it! If only I could substitute my gears and chain into your machine! I'm prolly doing this all the hard way. Anyone know what Edison said when they asked him how, after alot of attempts, he got the light bulb to work? He said "I ran out of ways for it to not work!:" Thats me n Blender...but there are sooo many options. $\endgroup$
    – dmac1
    Jan 20, 2017 at 3:14
  • $\begingroup$ Thank you Paul! Your response was just enough to get me over the hump...and now it works just like yours including a machine controller. And I didn't remember but just heard during Trump's inauguration....Edison tried about 10,000 ways to make a light bulb work. My blender efforts don't come close to that, but it felt like it sometimes when each step forward would take about a day. Thanks again to all. Now to make it work when rendered. $\endgroup$
    – dmac1
    Jan 20, 2017 at 18:50
  • $\begingroup$ I tried to use my solution according to your situation. Tried to download the .blend, but with no result (don't know what's wrong with it). Maybe you should upload it once more. BTW The Edison's quotes you provided are very motivating ;). $\endgroup$
    – Paul Gonet
    Jan 20, 2017 at 19:01

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