Mechanical rigging problem (SOLVED)

Hi all, hope you are safe and well;
I’m trying to fully animate this steam traction engine and I have every thing worked out except joining the fly wheel rig to the rest of the parented model which has drivers for the 4 wheels.

And here is my problem

And here is the fly wheel movement shot
Engine 3
Any help would be greatly appreciated.
:thinking: :australia:

Sorry i forgot to mention that the fly wheel rig is with bones done from Olav3d mechanical rig tutorial.

Not 100% sure exactly how this is setup, but if I’d guess I’d say you might want to use a bone/s for a global and/or local controllers (“Global” to move everything for positioning, optionally “Local” for animating the object moving. So you have all mesh parts parented/skinned to bones and those bones parented to local and/or global bones (used to control general movement of the whole vehicle).

This way you’re working in pose mode for animating, which is what you’d do with many rigs that use mostly bones for structure and controllers. Since you have some bones, but looks like objects for controllers, I’m guessing there’s an issue with non pose mode for bones but moving everything with objects as controllers, or something there, etc.

I can’t find this tutorial to see what you might have done, but something is not right! Can you post a blend file for me to look at? Please also link the tutorial so I can see what he did.

For me tis would have a “root” bone that all the non-moving arts are bone-parented to, bones for each wheel that have a driver based on the position of the root bone, same applies for the flywheel, these bones should be parented to root in the armature. Do you have pistons? in which case I would use an IK chain to drive the pistons and connecting rods.

If you can’t post blend file, I can do a quick mockup for you.

Mixing drivers based on empties and armatures is not best practice, when you can base all your drivers on a bone, thus keeping all actions in one object.

Cheers, Clock.

1 Like

Thank you both in replying, the olav3d tutorial was an old 2.79 tutorial

And this is what I followed for the 4 wheels.

And here is the packed blend file.
Traction Engine.blend (4.9 MB)
Maybe I still don’t know enough about animation to keep myself out of trouble as yet.
I appreciate your time and effort :australia:. :nerd_face:

Can’t argue with you on that!!! :smile:

So some things that are wrong:

Unapplied rotations on your meshes and your collection of armatures - these will FUBAR everything you are trying to do… Always apply rotations and scales if you do any of these edits in Object mode (Hint do them all in EDIT mode). To apply these, select all objects you have messed up in Object mode and key CTRL+A => “Rotation & Scale”.

Mixture of bones and empties to control things.

Wheel drivers not based on movement of vehicle - this should be the case!

Drivers not based on wheel radius, driver rotations are in Radians, so the scripted expression is always var / wheel radius - where var is forward movement of vehicle.

IK chain length not set, wasn’t in the tutorial either naughty-naughty! As soon as you have more than 1 IK, or not a traceable path back to root bone, your IK’s will FUBAR, if you don’t set the chain length.

Armature(s) is(are) a real (how do I put this) cock-up, bones not visible, blah blah blah. Multiple Armatures, how did you ever get this to even vaguely work? ONE ARMATURE PER MODEL from now on please. :smile:

Sorry, I am being harsh here, but start off with good practices and you future life as a mechanical rigger will be so much easier…

Here is a sample rig for you to look at:

Look carefully at all Bone parenting, which bones do not inherit scale, etc. “Bone” parent all objects to their respective bones. To animate this, simply move Root bone in X axis, I have keyframed it for you:

traction-engine-rig.blend (698.7 KB)

And look at the drivers, which have positive and which have negative expressions, this reverses wheel rotations, etc.

Nice model BTW… We should have more mechanical stuff here.

Cheers, Clock. :beers:

PS. Are you from “down under” by any chance? :rofl: :rofl:

PPS. those tutorials have soooooooo much wrong with them… Why do people who can squeeze a face spot think they can do brain surgery?

Thank you very much for helping me out here. :grinning:
And yes I am from “down under” Tasmania (west coast) actually.
Being a 63 year old fart sort of makes it hard to get my head around some thing totally new but I intend to get there. :thinking:
Many thanks again; now I have some studying to do.
I’m glad you like the model :grin:
:australia: :nerd_face:

I will be 64 next month… And I am pleased to help out. :rofl:

Cheers, Clock.

I did this some time ago:

I’ll find the rig if that helps, it is on my server… somewhere!

Cheers, Clock. :uk:

Thank you for this.
Talk about inspiration; this is great !
:australia: :nerd_face: