Mechanical Prototyping Set?

[drventure]

Just wondering if anyone had any thoughts about a good tool or set or kit to prototype out mechanical movements.

I know there's PC applications that do this kind of thing (ie simulate motion of levers, gears, etc), but I'm really hoping to avoid spending much money for such a thing. Maybe there's an open source app like GIMP for mechanical simulation?

If not, I was thinking possibly Erector sets or Kinex.

Maybe there's something else out there even better?

The reason is I need to come up with a mechanical movement to shift and pivot a monitor as it's lifted into place.

I've got several ideas, but it'd sure be nice to prototype things out before committing to any cutting and welding 

Any thoughts?

[Le Chuck]

I do all my mechanical prototyping in cardboard and use brads and dowels for moving parts.  As for torque issues I always defer to the material spec and I've never thought to engineer anything that angle bar or plate can't support anyway.  Shift and pivot sounds like all you'd need is guides or tracks.  Can you give more detail on what the monitor needs to be doing? 

[RandyT]

Just wondering if anyone had any thoughts about a good tool or set or kit to prototype out mechanical movements.

I know there's PC applications that do this kind of thing (ie simulate motion of levers, gears, etc), but I'm really hoping to avoid spending much money for such a thing. Maybe there's an open source app like GIMP for mechanical simulation?
...
Any thoughts?

Pick up a cheap copy of COREL Draw.  I used to use this before I entered the world of solid modeling.  COREL Draw is dimensionally accurate, and allows you to move pivot points and swing things around to check for clearances.  You won't find any kinetic animation in it, but once you learn a few tricks, you can do a lot with it.

[EightBySix]

I was looking for something like that when I was trying to get my head around a fold away control panel.

I came across freecad in an unrelated project at work and made a mental note of it, but never took it further.

Seems to do what you want, but after having a quick look around, it seems like quite a steep learning curve.

I bought some kinect for my son [ahem] but ended up with us building a roller coaster instead. 

[drventure]

Here's a simply mock up of what I'm looking to do.

Notice that the screen has to be stowed back a bit to allow clearance for the knob backends (and a 2" mini monitor, we'll see if that's going to work out!)

Anyway, my first thought was to mount 2 slides under the top and hinge the screen off them, but I'm not sure anymore

It might be a that a lever arrangement would work better.

Or maybe the whole design is nuts 

A linear actuator will be positioned vertically right about in the center of the cabinet, to lift the top evenly.

If possible, I'm trying to come up with a way to shift/tilt the screen via the motion already available through the actuator. I'd prefer to not have to buy/fashion a second actuator....

[EightBySix]

Thats a similar movement to one I was considering for pop up joystics in a drawer, only vertical instead of horizontal. Looked at a couple of possibilities that might be of use.

First was the mechanism that is used for cantelever toolboxes, like each drawer in this example:


Another thought was to use an arrangement of 'linear cams' as in this site:
You could have a cam follower for the top and bottom corner of your pop out screen and control the movement of each independantly.

Dunno if that helps...

[drventure]

That's along the lines I was thinking. Some kind of dual lever arrangement that's triggered by the top nearing it's fully raised position.

I'm going to check out some of these drafting apps and see what I can some up with.