Drawbridge

Hi there,
I'm designing a special purpose machinery that has - for want of a
better phrase - two drawbridge leaves. I'm trying to constrain them
using limit angle mates so that they both start off aligned
horizontally and then rise together to a limit of say 10 degrees from
the horizontal. I've put in a limit angle constraint of 180 to 170 but
when I move one leaf up the other leaf drops down (it's still at 180
you see, so it isn't in effect doing anything wrong). Is there a way
of making sure that they both only go above horizontal and not below?
Thanks,
David

 

Can you add a gear mate so they behave as if they were tied with
gears?

WT

 

Hi David,

Use the gear mate.
First of all add a constraint so that the drawbridge is level, then
suppress this mate, then add the gear mate to the two rotating axis of
the leaves.
Use a face or a sketch line and set an angle limit mate. It is best
NOT to use an angle that use's 0 deg as a limit, as it locked my
assembly.

Pete
If you send me an email address I will send you my very basic model as
a guide.

 

You could create a sketch with the required mechanism behaviour and
insert it as an envelope part in the assembly. Then you would only have
to work one leaf and use a horizontal constraint to get the other leaf
to follow.

TOP

 

I like a symmetry mate to link (2) parts to mirror behavior. Right
plane with the orgin of each other part. (or top plane or axis.)

Blair