Bike chain problems...

[Korken]

Hi all!

 

I'm making a bike chain with sprockets and, I can't get the chain to work at all.

Does anyone have an idea how to make the chain follow the sprockets?

I have 1 bone for each link in the chain and I'm using A:M v11.1.

 

//Korken

[DanCBradbury]

wow... thats quite a lot of moving parts like the rubics cube bone constraits... i think this one's gunna be complicated. but maybe someone around here will know

[luckbat]

http://www.hash.com/forums/index.php?showtopic=9749

[arkaos]

Korken,

 

A good approach would be to create a motion path via spline and constrain the chain bones to follow the path. Animate the sprocket rotation separately, maybe in a loopable action. A little tweaking should yield some good results. I've never tried it personally, but it should work.

 

Whoops, never mind, luckbat beat me to it

[Rodney]

Thanks for bumping dhartman's bike chain project back up Mike!

It works pretty well in realtime via the HA:MR Viewer if I do say so myself.

[Korken]

Thx for the awnsers! It realy helped!

Now I gotta do some tweaking.

 

//Korken

[Korken]

Does anyone know how to make a bone go a full lap around a path at 50% on the Ease in the Path Constraint?

It has been done in dhartmans chain loop but how did he do it?

 

//Korken

[Korken]

I think I've got a pretty good moving chain now.

Tell me what you think!

 

//Korken

[attachmentid=11414]

chain_movement.mov

[DanCBradbury]

That's pretty good... but i dont think that chain would work in real life... it's only like half of the track long.

[Korken]

Hehe, yeah. But is is only a test at the moment.

I will make a full chain when I'm done with the sprockets.

Ohh yes, does anyone have a good reference image in a front sprocket?

I found many but all of them where in bird's eye view.

 

//Korken

[arkaos]

Nice chain movement. I think you got a winner, here!

[jpappas]

Korken,

 

I also tried my hand at making the chain and noticed it was a bit unclear in the original example as to how the bone went completely around -- but I think the trick is that path is actually wrapped around the shape of the path twice, so the part of the path that goes the second time around is laid at the same spot as the first part. This makes it appear as one path but gives you the extra 50% you need to move the bone back to the start position. This isn't easy to describe and a bit tricky to do but if you need more help I have some notes on it, or perhaps someone with more know-how might step in and describe it some more.

 

On the other hand, I also noticed another thread here in the forum recently talking about pulleys/chains, etc., that simply took a circlular model and used a distortion modifier in an Action to make it into the shape of an ellipse to make it look like a chain. Rotating the original bone worked fine on the new shape. It seemed a heck of alot easier to implement.

 

-Jim