Join the dots ... a bit of Autocad (any version) fun.

[John_C]

With apologies to the mods in case this is in the wrong place, but I couldn't see a more appropriate location.

So, a friend has set a little problem for me, and unfortunately I'm struggling with it, so I thought I'd throw the question out to a wider audience.

What I need to do is to connect all of the similar coloured dots (circles). Have a look at the attached jpg and you should get a flavour of what I'm trying to do.

8880 Model.jpg

If anybody fancies having a play, I've sketched a dwg with the 6 fixed length components (blocks A - F) and the donuts are free pivot points.

The geometry as sketched is more or less right, in terms of the alignment of the two top members, but obviously the mid member doesn't connect, so it's not right.

8880 (R2010).dwg

So if anybody can come up with a solution (I'm sure that there are many possible solutions), I'll buy them a cold one. If anybody can explain to me how I can investigate alternative solutions, other than trial and error, I'll buy them a 6 pack ...

Cheers

John

[StDoodle]

I've only scratched the surface, but the enclosed version of your file should get you on the path.

[John_C]

... should get you on the path.

Indeed it does, many thanks.

[edit] ... that's the kind of methodical approach that I was missing ... [/edit]

[BeKirra]

Here is another one.
You won't miss if you follow the steps which I have done.

[arshiel88]

Simple solution....CONSTRAINTS.

check this out.

[John_C]

Simple solution....CONSTRAINTS.

check this out.

Wow ... I've never used constraints, they look very cool. I shall have to investigate further, thanks ...

However, following on from StDoodle's post, I attacked the problem methodically in a similar manner to how I would have solved it on the drawing board. Here's what I did:

Firstly, I know the arc that describes the possible starting location for the cyan dot, so I divided it into segments. From the points on the cyan arc I drew circles to give intersection points on the magenta arc. Then I connected these points and extended the lines by the distance between the magenta and "brown" dots.

The end points of these rays describes the path that the "brown" dot must follow. By offsetting this path I get a path that the "purple" dot must lie on, and the point where this path intersects with the remaining arc must be the solution. Simple, kind of ...

... and yeah, I know, I've played about with the connecting lengths, but the principals still apply. Now to start playing with CONSTRAINTS ...