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Struggling with animation
william_frame
Member Posts: 14 ✭
https://cad.onshape.com/documents/17147aecf8c6f86ca92cff2f/w/2aea5156fa1df24d42cd2ec9/e/1aef2cdc17c206b2ce472d73
I am trying to draw and animate the components of the steering for our cyclecart. The parts are a "fulcrum" the rotates back and forth on the steering shaft. This links with a Heim joint to the tie rod which has a tie rod ball joint on the other end. The tie rod ball joint connects to the Ackerman Arm which pivots on the King Pin. My goal is to see is where as the tie rod will impact the barrel that the fulcrum is connected to thus limiting the rotation of the fulcrum. I am trying to make the mounting plate, the fixing plate and the King Pin to be fixed in position. I would like to have the animation of the rotate of the fulcrum on the steering shaft (Revolute 1) swing the fulcrum back and forth, which will cause the Heim joint to rotate (Revolute 2) and pull or push the tie rod. The tie rod via the tie rod ball joint end would swing the Acherman arm accordingly around the King Pin. Individually all of the rovolutes seem to work as expected, but the ball joint doesn't seem to be working.
Obviously, I am doing something wrong. I have seen numerous examples of far more complicated parts interacting, but this has me stymied.
Any suggestions or help will be appreciated.
Bill Frame
Comments
your Ball Joint Rod End's are grouped together. that means they're fixed relative to each other.
this prevents the Tierod from pivoting around the z axis and therefore the Ball Joint Linkage cannot follow the AckermanArm.
so when you put a proper ball mate betweeen the two Ball Joint Rod Ends (possibly in a sub-assembly), things should work out….
It took me a while to completely understand your comment, but I finally have it working (most of the time). The big issue was that the Ball Joint Rod End needs 2 mates: a Revolute between the Pivot Rod and the inner part of the joint and then a Ball mate between the same inner part and the outer casing of the joint. Once I got to that point, things started working. I have added the other side of the steering to the assembly and now the main version is working correctly. Thanks for pointing me in the right direction.
I think I am getting close to having enough information that I can start actually building the parts.
I have been playing with this. The Ball mate seems to be correct; when I "run" the mate connector in the edit mode, it moves the ball joint as I think it should.
The problem seems to be where the TieRodEnd is Fixed to the Acherman arm. As soon as I activate that connection, the animates fail. With that connection suppressed, each Rotate connector seems to animate correctly. Unfortunately, without the TieRodEnd fixed, the rotates do not move the next piece in the mechanism.
Still working on it, but additional help seems to be needed.
Thanks, Bill
Seems like you figured it out. Animation seems fine and there are no suppressed connections when I open it
I have the animation working in one Assembly. However, when I duplicate the assembly and then move where the TieRod End joints mount to the Ackerman arms, I have a problem. After I move just the right side TieRod end (fasten mate Ack-TieRodEnd1) to the second hole, the animation works. But when I move the other end (fasten mate Ack-TieRodEnd2) to the second hole, it is failing with the message: "Unable to compute any steps for this animation. Unable to apply transform. Instance(s) may be constrained "
I can drag a part in the assembly and it moves correctly, but the animation will not work.
This seems to be specific to the left side of the assembly (the side without the compass). If I move just that side it fails as soon as I try to animate it.
There are three assemblies: SteeringLinkage-Long (original) works as expected; SteeringLinkage-Short works, but only because the left side has not been moved; and on SteeringLinkage-Mid both ends have been moved resulting in the animation failing.
I have looked at everything I can think of, but cannot figure out what is happening.
Again any help is appreciated. Link is in the original post.