Altercations with Animations

[BikeGuy]

Hey there;

Are any of you familiar enough with AI animations to help me troubleshoot a problem?

I've been working on an animation of a hub which is screwed together. I've added tweaks to all of the parts and for the threaded parts I've grouped the linear and rotational tweaks. In the animation the outside locknut rotates correctly onto the threaded axle. However the ball-bearing cone will not properly rotate.

(if you're not familiar with animations, here's a great tutorial).

The animation and AI file are too large for this forum, so I've loaded them up on my website. You can download it here - w w w . tarfman . net / hub-animation . zip

If you have any ideas on this I would be thrilled to hear it.

thanks in advance

(PS-the rules about posting urls are extremely frustrating)

[shift1313]

how did you set up your constraints for the bearing/cone. when you setup up your constrains for something like a nut going onto a bolt. You need to setup a pin constraint to keep then aligned, then you will need a rotation/translation constraint. For the ball bearing/cone you can probably do it a few ways. you can have the pin constraint and then a rotational constraint between the inner race and outer race, that has the outer rotating opposite of the inner. if you wanted to get really time consuming you could implement constraints between all the balls individually to the inner race, then the outer race to the balls. the first way is much easier.

 

I havent used anything past 11 so im not sure on procedure when setting up 08. I assume since autodesk changed their navigation of all the other programs in 08 that Inventor changed as well, but im not familiar with "tweaks" that you refer to.

 

hope it was a little helpful and not counter productive:)

[BikeGuy]

Thanks for the suggestion on constraints as related to animations. I used a tangent constraint (see picture for those of you who also want to learn this also). Now the parts do rotate in the animation (which I can't upload because it's too big). But the tangent constraint is not as precise as constraining cylinder axes. The tangent constraint allows the nut to 'jiggle' with relation to the cylinder. Did I misunderstand your post about a pin constraint, or is this just the nature of the beast?

Secondly, is there a way to reduce the size of animation files? I tried both ends of the compression quality scrollbar and the .avi file is more than 2500k even when zipped.

I appreciate all the great help here.

hubtest.zip

[shift1313]

im not sure about the video compression. I typically make my renders under 15seconds so size isnt too much of an issue.

 

As for the constraints. ive never used the tangent so im not sure how this would work in the animations. I typically use pin because most of my stuff rotates but does not translate, or it translates but does not rotate.

 

For instance an air cylinder. I use a pin constraint for the piston inside the cylinder body, then when i animate, i use animate constraint and use the offset to move the piston.

 

So if you were to apply this to your nut/thread you would have to animate the pin constraint from 0-10(just for random numbers) and at the same frame segement you would also have to animate this nut to rotate however many degrees per your threads/inch. unless they are setup as driven constraints.

 

im assuming the tangent constraint is "jiggling" because of the space between threads?

 

 

i believe if you set up 3 constraints on your nut, pin/ rotations/transitional it should achieve the effect but i have not played with this specifically. Now that im curious i will try tomorrow morning at work though:)

[shift1313]

okay i played with it really quickly when i got in this morning so no comments on the model:) I used two constraints and got it to animate correctly. I used a Pin constraints, selected the nut first and the threaded rod second. Then i used the rotation/transitional constraint second. selected the nut first for the rotation, and the threaded rod second for the transition. The first selection is the "child" and the second is the "parent" typically. Then for the animation i animated my pin constraint from 0 to -5inches in my case. because of the rotate/transition constraint this made the nut rotate as it moved. The dimension you put for the rotate/transition constraint will be how far it travels in 1 turn. I set in to .5" but really for 1/2-13(like i drew) it would be .076" per revolution.

 

here is a screen shot and animation.

 

 

[shift1313]

i just realized something. When you mentioned tweak. The file you have open is not an assembly file(.iam), its a presentation file(.ipn). The tweaks allow you to "explode" components and animate this. You want to be in an assembly file and in the inventor studio application. Im not sure how that is setup in the newer versions but i imagine that it did not change.

 

 

As far as i know the presentation file is what you would use to show a components assembly process.

[BikeGuy]

Shift sorry for the confusion. I was waiting until I had enough posts to create a reply with web links.

Every reference that I've looked into has taught that presentation files are the place to create animations (by exploding and creating an .avi of the re-assembly). I've looked through my books ('Autodesk Inventor Inside and Out' and 'Autodesk Inventor Essentials Plus') which also say to use presentation files.

You can see what I am trying to do in this tutorial.

http://www.youtube.com/watch?v=YhYYZTGi6JY&feature=related

http://www.youtube.com/watch?v=YhYYZTGi6JY&feature=related

It's in two parts and if you watch carefully you can see that he made a small mistake.

Anyway though, I tried the method you suggest in assembly views and I can understand it a little (it's similar to 3D Studio), but not enough to make two component animations run at the same time. All of the component animations appear to run in one Is there a good learning resource for this?

How does everyone who does animations feel. Is presentation or assembly view the better option

[shift1313]

sorry bikeguy as i am probably not the best reference for this, but when i animate components like the thread/nut i did above, i expand the drawing tree on the left, right click on the constraint i want and use the animate constraint button. The error you received above means you are trying to animate the same constraint in two different ways at the same period of time. The animate component is what i would use if you were say bringing that nut in from a distance away from the part.

 

The inventor studio that i use is typically what you would use to check motion simulation of an assembly(i think) and check for clearance issues. The presentation file is like you said what you would use to show assembly(i think).

 

 

When trying to move two components at once you just need to make sure their times overlap. This should work as long as they are not the same component.

 

 

ill check those videos out later today and reply back.

[shift1313]

wow i just wasted like 45mins on youtube looking at inventor and solidworks vids:)

 

were you able to get your file to work? If you are just trying to make and explode or assembly vid of your assembly i think the presentation file would work just fine. It seems as though the rotation and transition is just for looks in the explode animation. I do not believe the presentation file has anything to do with your constraints in the model, at least thats what i gathered from that video, where the inventor studio is the opposite.

 

For your nut/shaft it seems like you would just do a translation tweak and a rotation and then group them together.

 

Let me know if it works out for you. Ill give it a shot tomorrow before work.

[BikeGuy]

Well I don't know how it worked, but I redid the animation a couple of times and it works now. I'll work on this some more to improve the camera angle and zoom in on the details.

http://www.flickr.com/photos/60961560@N00/2969205259/in/set-72157607894122095/

thanks for your help

[shift1313]

very cool, glad you got it to work! from the look of the file id say thats the presentation file right?

 

Are you drawing the entire bike? the countersink thread i noticed you had a bar clamp(not sure the correct term). that goes from your stem to your bars.