piston and crank

Support Animation and Rigging
1

I have been trying to make a piston and crank animation…mostly I have it, but there is still some “slop” in the way my IK target moves. Notice the tip of the piston rod in the .blend file, the emtpy I used as an IK target sort of “wobbles” up and down at the very tip.

http://www.imageox.com/image/6622-piston.gif

2

Sorry in german but Anyway:
http://de.wikibooks.org/wiki/Blender_Dokumentation/_Tutorials/_Armatures/_Kolben_und_Zylinder

3

Well…I tried running it through google’s language tools…but some of it still gets garbled in translation…sigh. Interesting setup, tho. I will have another go at looking at that link when I have more time.

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4

There is a link to where the .blend file for that can be downloaded. I got it…still in german, of course. The setup is more complicated than mine, but there is still slop, only in the horizontal rather than the vertical.

5

I would take a look at your blend-file, but I can’t download it.

6

I see absolutely no wobble at all either in the Empty or the piston.

%<

7

i had the same wobble problem in my 2D animation, im downloading your file to see how you did things. If you figure this out you have my unending gratitude.

8

ive got no slop either thanks, my last animation looked like it had Piston Slap.

now i can go through and clean up the models, in a few weeks i’ll post an engine for you.

9

I see absolutely no wobble at all either in the Empty or the piston

Are you talking about in mine? It’s there, but it is fairly small…just inside the ball at the tip of the bone. Same thing with the one from the german site…very small, dunno how many BU’s. I think it is a speed issue between the movement of the empty vs the movement of the other end of the bone as it travels around the crank path.

10

Well, I do see the sloppyness (go to edit mode)
This should do it:
http://rapidshare.de/files/35610766/piston-solved.blend

11

I would take a look at your blend-file, but I can’t download it.

The link doesn’t work? I just tried it…the only problem is the site likes to bury the link in all the advertising garbage.

12

Yup, that did it…similar setup to the german one, but yours has no slop at all. Now I just have to try to understand what you did and how it works. (I am a dreadful n00b)

Anyway…thank you very much for your solution!!!

13

Hey there, was just lookin at your nifty litle piston setup there, im doing someting similar. but im new to blender and im not sure how to “attach” the rod to either the piston head or the crank, i have dumbed my way through it by setting up LOCROT keys in the IPO mode. any help you could give me would be great if you have the time

Thanx again

14

I’ll try and translate the tutorial, but my english is … improvable. :smiley:
http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro/Advanced_Tutorials/Advanced_Animation/example/_Piston%2C_Rod_and_Crank

[edit]
I’ve finished the translation, but it needs for sure heavy corrections…
[/edit]

15

i have one problem with your animation.

I copy and paste the objects and line them up side to side like a 4cylinder. However when i hit animate, the end of the connecting rod on my copied objects moves itself back to where the head of the original piston is. So it looks terrible obviously.