How do motion constraints work?

[Gherkinman]

I'm having a problem getting some constraints to work properly. Basically, I made some pneumatic pistons and constrained the bore to the tube. They line up properly but the tube sticks out the same direction as the bore instead of towards it, so the bore isnt inside the tube like it should be. I cant just flip the tube around because the contraint "works" and the two parts move together.

I tried isolating and editing the whole assembly but when i edit it, it appears fine. Then I finish edit and it's backwards again.

I figure if I can somehow contrain the bore to move only within the tube caps it will both:a) Not look so bad by sticking out if its moved too far and, b) Actually get in the tube!

Can anybody provide some insight on this dellemma/ tell me how i can take a screenshot so i can explain it better? Thanks.

[JD Mather]

Zip and post your files here
http://discussion.autodesk.com/forum.jspa?forumID=78
should take only a few minutes to fix.

[Gherkinman]

Will do, seriously though. How do you take a screenshot? I press print screen like 5,000,000 times :ahh:

[EricH]

Will do, seriously though. How do you take a screenshot? I press print screen like 5,000,000 times :ahh:Try shift and printscreen. At least on my keyboard, that's how it works. (I think)

As for the constrain, try doing a flush constraint with an offset between the end of the pison rod and the end of the cylinder you want it at (then removing that constraint later.)

[Gherkinman]

I posted the .zip on the autodesk forums under "116 grabber contraint issues"

[spinmunky]

Will do, seriously though. How do you take a screenshot? I press print screen like 5,000,000 times :ahh:

press print screen then go into a image editing program (ex.Paint) then ctrl+v (paste)

[rohit]

First, put a constraint on the axis of the 2 cylinders, and then use a flush constraint to get the rod aligned

[Gherkinman]

Thanks for your help guys, the problem has been resolved :D