Problem with Spin modifier

Mosk the Scribe

I'm using the DAZ Humvee in C8.5 Pro.

I placed a spin modifier on the back wheels for .15 revolutions per second (on the x axis because that's how these wheels are set up) and it works fine.

When I place a similar spin modifier on the front right or front left wheel (on the z axis, because those wheels are oriented differently), it works fine for the first 1.5 seconds (which equals 1/4 of a revolution) -
The orientation of the wheel reads 0 (for X), 90 (for y) and -0 (for z) at this point.
Rotation is -0, 0, and -87.75

The next frame animation still looks okay but rotations now has changes to x and y values,
-1.82, 1.82, and -90

And the following frame, the wheel flips around -
Rotation 30, -180, -85.50

From here the wheel continues a slow backward rotation on the z axis all the way down to 0, and then back up to 87.75 at 4 sec. 23 frames

At 5:00, the wheel flips back around to the correct side, rotation flips back to
0,0, 87.75
and things animate properly through 8 sec 7 frames -
with rotation of -0.0.-87.75.

At 08:08 becomes -.6, .6, -90

And at 08:09 the wheel flips again to rotation 30, -180, and -87.75 and continues the backward rotation

This weird behavior happens with both front wheels.

Neither have any keyframes - just the spin modifier.

Any ideas on what could be causing the problem (or best ways to work around) - I'll try manually resetting wheels to 0 rotation when they flip, but not sure what's cuaing problem in the first place. Using linear tweeners without any easing.

EDIT - tried typing in new values for wheel rotation in the motion panel, and that does shift wheel, but it replaces my values with its own - so if I type in x 0, y 0, z -90 I still end up with -15.91, -4.72, and -270

Thanks for any help. (I had hidden some vertices in model room - but don't think that should cause this kind of behavior; don't have an animation track and no idea what's causing this override of my normal values)

WendyLuvsCatz

First of all make sure the hot point is centered on the hub for all spinning parts
This seems like your issue

Mosk the Scribe

Hey Wendy-

I looked at the hot point and it seems centered and isn't animated (checked sequencer and looked at graph editor as well)

Eventually I just loaded a new humvee - and that one works fine

Somewhere along the line I must have broken the first humvee - even though you'd figure those are built to be durable. I know I'd hidden some polygons - maybe I accidentally deleted some. Found a rotation morph on a level of the humvee I hadn't looked on as well - and that too was giving the strange behavior on the broken humvee.