Cineversity

I’ve set up a very simple rig with a conveyor belt. Adjusting the offset works just fine. However, when trying to keyframe the offset, it gets messy. Any idea what I might be doing wrong?

And just thought I would point this out, but opening the project in R15 looks different compared to opening it in R19.

Thanks!

Hi Matt,

Thanks for the example scene.

Do you know that effect in movies when the tires/wheels seems to turn backwards? That is pretty much the setting with the 900, only reverse, kind of.

Anyway, type -2700 instead of 900 into the Range Mapper, and it should work.

Your scene file:
https://www.amazon.com/clouddrive/share/MWPHiLAvEpnnejrZ8zEsFz8HZ15C0Ge68Fc6OcTHWOg

All the best

Ahhh okay that makes sense Was there some kind of mathematical way you came up with the -2700 number, or was it just kind of trying different numbers until you arrived at the correct one?

Thanks again!
Matt

Matt, the key to simplify “cog-wheel” calculations is to count teeth. The belt has 75 and the wheel has ten. (… don’t worry, I didn’t count all the 75, I measured the points of 10 and extrapolated to the complete length, but counting works as well).

The ratio of 75/10 is 7.5 So the number was 360º x 7.5 = 2700º. (Given the 0-100% as input in the Range Mapper)

I know there is always the suggestion to take radius or diameters, but that has to be in the center/middle of all parts, and then it becomes a longer number story. Teeth need to fit into each other, and it is a simple math then which just works very precisely. This is the way I have suggested to do it since over a decade, no one has complained so far.

Since I noticed that they move initially backwards, the number had to be negative. More in detail: My first set up was, scene time to 0-100 frames and the animation 0-10%, first as a spline then as a linear interpolation, just to get clear what happens. With this set up, I was able to see the relation of frame and offset. Just to get familiar with the scene, while assuming anything could be a problem. With this new knowledge, the next step was just counting teeth.

My best wishes

Thanks so much for the info Dr. Sassi! This makes sense, I appreciate it.

One kind of unrelated question… When they introduced the new Cogwheel updates that’s great, and I love being able to add Inlays. However, how can I make it so there are no curves in the teeth? I just want flat, hard edge teeth. I can do it if I enable legacy mode, but then it won’t let me add Inlays. Is there a way to do this?

You’re very welcome, Matt.

This is possible in Legacy Mode:

Go to Attribute Manager>Object>Legacy.
Then set the Middle Radius to the outer or inner radius, each results in a different cog-wheel, I guess inner radius is preferred. If you adjust the Bevel, alone or with the Middle, you should get what you are after.

Then set up the Inlays in a second Cog-Wheel, with a Spline Mask. Zero teeth here of course (as in delete or use them small inside as extra shape).
Perhaps connect the “main”-parameters of one to the other.

Enjoy your project.

Okay yeah I didn’t know if there was another method. I ended up using a circle and cogwheel inside a Spline Mask. Seems to work okay. Just wonder why they didn’t build that functionality into it by default.

Matt, there wasn’t another method to my knowledge, I just combined them. I had no need nor a question that would have led me to this, other than your question about.

Here is an example:
Scene file
https://www.amazon.com/clouddrive/share/jTstW3ATr2nBKwcKNKpjg1DfdNInt3aFAZgt0V0Tf1A

The simple version pulls the teeth to the center, where the axis would be. So the teeth of the new version would be hidden. If that is not an option, a second Spline Mask needs to be utilized. Both versions are in the file.

ENJOY

You are awesome Dr. Sassi. Thank you so much for your help and for the scene file!

Matt

Very kind of you, Matt. Thanks a lot.

My best wishes.

P.S.: I had to find a smaller solution, to have that “center hole” clear, without a second Spline Mask.

Please have a look here:
Scene File
https://www.amazon.com/clouddrive/share/E6qi8iTQ7Hk2h8C25ffd9eHHYSu5wIBwXxrCee6wrsd

The Teeth are set to “Flat” and the “Addendum Radius” to larger than the other cog-wheel.

Another option would be to set it to “None” instead of “Flat”, but with the Flat we get an extra option to construct the teeth-tip for example.

OR: just split it, to have a lot of more options to create (shape and material wise):
Scene file
https://www.amazon.com/clouddrive/share/lXCHqIvfGmWQXppS2ZKf4CLda5xiwgne2puXkZGzAG

Oh that’s an interesting solution too! Thanks again for your help Dr. Sassi!

You’re very welcome, Matt.

Enjoy.