mechanism

I'm trying to teach myself mechanism. I have a four arm mechnism in which I
have redefined the assembly as pin joints. I have selected axes to align and
selected faces. I noticed the default face alignment seems to be align, with
no option for mate. anyway, my assembly regenerates fine.

Then I start mechanism, and it looks fine, but as soon as I select drag,
some of the aligned faces invert, causing incorrect assembly. If I cancel
Mechanism, and do a regen, the parts line up properly again.

Has anyone encountered this and do you know what I'm doing wrong?

Thanks,

Dave

 

: I'm trying to teach myself mechanism. I have a four arm mechnism in which I
: have redefined the assembly as pin joints. I have selected axes to align and
: selected faces. I noticed the default face alignment seems to be align, with
: no option for mate. anyway, my assembly regenerates fine.
:
To overcome the absence of the mate option, you can select the axis aligment input
of your pin connection and 'flip' the direction with the button at the bottom of
that input box. This will turn an align into a virtual mate. Use this instead of a
tranlate offset. I've found no problem of accidentally flipping alignment in
Mechanisms when I've done it deliberately this way.

David Janes

 

Yeah, this seems weird. I redefined the offending joints, and found that by
pressing flip once it inverted the parts the wrong way, so I pressed flip
again which made the parts correct. Then when I went into mechanism it was
fine, it didn't flip the connections over. Can't understand why it did this,
I basically changed it and changed it back and it fixed the problem. Unless
of course flip isn't really a two-way switch but flips the axis then the
second flip flips the plane. I hate it when I can't figure out the logic.