View Full Version : Animating Gears Problem.

04-29-2012, 09:12 AM
Hey is this possible to do with Dynamics? I'm doing a project for uni and can't really use Lightwave 11 :( Having to Use Lightwave 9.6

Can someone take a look at the attached scene and possible tell me where i'm going wrong please?

The first cog is spinning but its not really doing anything to the other cog when comes into contact with it, have no idea why.

Maybe because I have the settings wrong on something more than likely.


04-29-2012, 09:27 AM
Didn't look but: in general dynamics for gears is a bad strategy, just too problematical.

If at all possible (maybe your instructor insisted you use dynamics), expressions are going to be far more reliable.

04-29-2012, 09:38 AM
We are allowed to use keyframe for some things so maybe I should use it for this lol.

Thanks for the feedback mate much appreciated.

04-29-2012, 10:13 AM
maybe try boosterlink...

04-29-2012, 02:18 PM
Expressions are pretty simple, especially once you start CUTTING AND PASTING them. That makes them tonnes easier.

Then you only have to keyframe one item, and the rest of the 'mechanism' is driven thru expressions to comply.

04-29-2012, 03:27 PM
You could just use the channel follower. Just link the gears rotation B to Gear:Layer1;Rotation B

Then as you rotate the 1st gear the rest follow. I see you have moved your gears in modeler to make them line up.... This is a bad idea, the centre of rotation for each gear will be in a different position!

I could post the scene, but I don't have to do homework any more. :hey:

Good luck.

04-29-2012, 03:32 PM
You could just use the channel follower. Just link the gears rotation B to Gear:Layer1;Rotation B
??? Gears rotate in alternating direction, #1 clockwise, #2 counter-clockwise, #3 clockwise again.

A "-1" is going to have to sneak in there somewhere.

Easy-peasy w/Expressions.

EDIT: actually, channel follower would work if you flipped gear #2 180 on its Heading. Since we'd then be looking at its back, the clockwise rotation would be reversed.

Of course, Expressions allow you to accurately have gears of different sizes being driven.


04-29-2012, 03:40 PM
Well spotted. :thumbsup:

It's -100% on gear number 2

04-29-2012, 05:07 PM
Heres your same scene,
I added Relativity to the gear in layer 1
so that it follows gear layer2s rotation.
Relativity has a professor (like a wizard) that
is specifically designed to help animate gears. Its
called Dr Gear Grinder. In your case the gears are the same
diameter so it was easier but its very helpful
with gears of different diameters. Basically you
input the gear diameters, which gear is the driving
gear and Dr Geargrinder creates the expression for you. :)

04-29-2012, 06:01 PM
Agreed. I always thought Relativity was made for the likes of gears. It doesn't get much attention these days, but it is one of the finest bits of code ever written for LW.

04-29-2012, 06:07 PM
The cool thing about relativity is that you end up with some kind of expression.
It takes a lot of time to really learn the syntax and sometimes the math involved with
more complex setups. Relativity has several professors that make the setup
process go alot faster, creating an expression that at least you can
go back and analyze later.

04-29-2012, 06:26 PM
Yes. Even better were the days before Relativity was integrated into LW, you could email Prem and he would explain how to do strange and wonderful things, and give you the commands and syntax. The Rel docs are hilariously cool too.

04-30-2012, 03:13 AM
Relativity was the tool of choice before LW had native expressions. They are still better in a lot of ways and Im glad NT aquired it. :)

04-30-2012, 10:04 AM
uploaded a preview of the Relativity scenes here btw,...

(gears can be seen 4:30 into the video...)