thanks very much for your help! I think it solved the issue with your solution.

Thanks very much!
As I have just started learning how to do DC, I just posted another model in a new thread to seek solution.
http://sketchucation.com/forums/viewtopic.php?f=289&t=48529
Please take a look to see if you have any idea.

DedongC

I have an extendable hook DC model. To make it extend its length without distortion, it seems to have to have it modeled in two pieces, one is a bar and the other is just hook part. My DC seems work, but the movement is not as clean as expected and it shows some gap between the bar and hook part during the course of the extendable hook moving back to it's original position.
Anything wrong with my formula or any other better way to make the two parts move together seamlessly?
Attached is my DC.

Thanks in advance

DedongC

hook_test.skp

Thanks very much for your explanation!
I modified the formula a little bit and can get it to turn in any circles and reverse by setting up two attributes(counter and timer). Attached is my modified DC model.

DedongC

my rotation test V6.skp

prokrastinator,
Thanks very much for your suggestion, I am going to learn how to use that plugin.
I just started learning the DC,Can you please explain a little bit about the formula that you used for the rotation? what the IF statement means to make the tire rotate and then reverse direction?
count_up_down =if(counter<=100, counter, 200-counter)

Thanks in advance!

DedongC

prokrastintor,
Thank you so much for your smart solution! and now I can use your formula to do any degrees(by changing the parameter 360),though I am not able to fully understand the code. You are great!
Just wonder if you can do me another favor? how can you make it turn forever in one direction like a real tire until click again to stop it?

Thanks again! This is a good site to seek solutions.

Dedong

I have a dynamic component set up to rotate like this when clicked:
ANIMATESLOW("RotY",360,0)
It rotates clockwise 360 degrees perfectly, but when clicked to return to 0 degree, it still rotates clockwise instead of counter-clockwise, no matter what degree I set for the second parameter. How can I get it rotate counter-clockwise after it rotated by the first parameter.
Any help for this?

Attached is my sketchUp dynamic component file.

DedongC

my dynamic component file.