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I'm hoping you can help.

I am working with a downloaded drone model. I wanted to animate the blades to spin.

I'm having an issue because the arms are at a slight angle. Rotating on the Z angle does not keep the blade flush with the arm as it spins.

I thought that this would be simple enough to fix (which I'm still sure it is), but I can't seem to find a working solution.

The closest I've got to work is parenting the blade section to an empty and spinning that. When I do so with the rotate tool, it looks perfect (as the X and Y fluctuate to compensate for rotation. However, when I keyframe the Z axis, it doesn't take the X and Y data. I am guessing there is a way of capturing this information that I don't know about.

I have tried so many solutions from this message board and also YouTube so decided to make a new post in case there is a specific issue here.enter image description here

I should also note, this is using a custom transform orientation using the angle of the surface below the blade.

I have updated some images below to show what I'm talking about.

Any help here would be much appreciated!

ddml
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  • If your blade is a bit tilted, the solution is indeed to parent to an empty and tilt the empty, the blade will only rotate on its Z. Not sure what you mean by "when I keyframe the Z axis, it doesn't take the X and Y data"? Could you please elaborate, maybe show some drawings? – moonboots Feb 27 '24 at 12:35
  • @moonboots.. is this a duplicate of your classic windmill answer? – Robin Betts Feb 27 '24 at 13:15
  • @Robin Betts it looks like there's another problem here but I'm not sure what – moonboots Feb 27 '24 at 13:17
  • Hey both, thanks so much for your replies.

    What I mean is when I rotate the empty manually and it looks fine, I can see the X and Y data fluctuating to keep the bases lined up. For example the X goes up to around 6 and then back down to 0 when a rotation is completed.

    However I can't work out how to capture that data in a keyframe. If I spin the Z axis using the rotation controls on the right, the X and Y are not affected.

     – ddml Feb 27 '24 at 13:49
  • Thank you for the windmill response. This is essentially what I've tried but it's not working. Any insight to where I'm going wrong would be much appreciated. – ddml Feb 27 '24 at 13:50
  • Are you sure that the origin of the blade is correctly oriented? Maybe share your file (only the useful objects): https://blend-exchange.com/ – moonboots Feb 27 '24 at 14:47
  • I believe the origin is correctly aligned yes. I've cleaned up the file and attached it here:

    Thanks so much again for your help.

     – ddml Feb 28 '24 at 10:33

1 Answers1

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I guess your problem is that you've applied the rotation of your objects while their local orientation were not aligned with their faces anymore. See the problem:

enter image description here

To realign the origin orientation with the mesh, first select a face of your mesh (for this one I first recalculated the normals because they were uncorrectly flipped), create a custom orientation in the Transform Orientations panel:

enter image description here

Then in Object mode activate the Transform Affect Only Origins option:

enter image description here

And Object > Transform > Align to Transform Orientation:

enter image description here

Once done disable the Transform Affect Only Origins option, and in the Transform Orientation panel come back to Global. Then AltR to reset the rotation:

enter image description here

Now if this object needs to be slightly tilted, parent it to an empty and tilt the empty, not the object! This way if the object needs to rotate it will do it correctly around its onw Z axis.

enter image description here

moonboots
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  • Thank you so, so much for the help here. I really appreciate it!

    The model had been downloaded from an asset library. I believe it was originally made in 3ds Max. Is it fairly standard for some of these issues to happen when working with models from other programs?

    I am trying to understand if I caused an issue through my process of trying to fix it, or if it's something that will always need doing when you put models into Blender without any data.

     – ddml Feb 28 '24 at 17:54
  • I can't tell, you need to check the origin orientation, especially if you plan to keyframe the rotation – moonboots Feb 28 '24 at 18:10
  • All good thanks. Looking at other pieces of the model, I think the origin orientation is off across everything. This was really useful. Thank you again. – ddml Feb 29 '24 at 11:17
  • You're welcome ;) ...................... – moonboots Feb 29 '24 at 11:30