Mechanics software

[catsketcher]

Hello all,

I have a few ideas for my little folding cat mecahanism that I would like to check on the computer. Does anyone know if Rhino can move parts to see if the parts touch when they move. I can make a physical model to see if there are any issues when the mechanism folds but would prefer to do this on the computer.

Is it possible to specify a series of hinge points and then move the system in and out? Is there software that can do this? I guess I could rotate the parts in Rhino and check the system in various orientations but would like to fluidly move the parts around like the real assembly.

cheers

Phil Thompson

[MikeJohns]

catsketcher
No , sounds like you need Solidworks or ProEngineer or SolidEdge or similar. Do you have access to any of these?

[yipster]

"Is it possible to specify a series of hinge points and then move the system in and out? Is there software that can do this?"
you need a time-line as is in software for animations f.e. acad and 3d max would do it

[CGN]

Blender and Gmax may be other option the two are free

[Raggi_Thor]

Alibre Xpress is free and lets you move or rotate parts and sub assemblies and add assembly constraints pretty much the same way as in SolidWorks etc. There is limited number of parts in the free version. You can open Rhino files iff you register the free license.

I am not neutral as I am selling this stuff (and Rhino + Bricscad) in Norway :-)

[Raggi_Thor]

Originally Posted by yipster

"Is it possible to specify a series of hinge points and then move the system in and out? Is there software that can do this?"
you need a time-line as is in software for animations f.e. acad and 3d max would do it

Acad is not good for this, I think.
Alibre, of course,
but maybe also Bongo for Rhino.

[Troutcatcher]

May I suggest a mechanism. The Kempe linkage might be the one you are looking for

[marshmat]

AutoCAD is a bad choice for stuff that moves, IMHO. It's essentially a digital version of the old drafting board and filing cabinet. Rhino, again, works with static objects; animation in either is a matter of mapping out, step by step, how you want things to move, and then rendering the sequence. You need a parametric modelling engine if you want to dynamically adjust assemblies in real-time.
SolidEdge (and SolidWorks, which I think uses the same modelling engine) is quite capable of doing what you want (we did a complete solarcar suspension, linkages and pivots all over the place, in SE recently), but the commercial versions are not cheap. They also require you to design the complete thing part-by-part and aren't great for quick-n-dirty sketching.

[Troutcatcher]

For those that like to model and explore linkages in Cinderella might be a choice. Crazy mathematicians and all kinds of "rocket scientists" love it.
However the graphics are probably not as fancy as MCAD

http://cinderella.de/tiki-index.php

.....and then there is the Bongo plugin for Rhino (maybe it contains a parametric solid modelling engine.... ACIS or Parasolid.

[yipster]

acad 2008 still dont animate?
acad 2007 has 3d and 3ds max out, 3ds max dxf in
it looks like some day it may be one but for now both autodesk programs can be downloaded as trials

[Raggi_Thor]

Maybe GrafiCalc from www.inventbetter.com ?
They say "If you can sketch it, GrafiCalc can solve it."

[catsketcher]

Thanks to all of my fellow boat nuts for the help. I will have a look through the cheap versions first. The mechanism on the prototype cat works well but I really want to fine tune the whole assembly right down to a few millimetres so doing it on computer seems sensible - especially since the thing is on the computer already.

Cheers

Phil Thompson

[marshmat]

acad 2008 still dont animate?
acad 2007 has 3d and 3ds max out, 3ds max dxf in
it looks like some day it may be one but for now both autodesk programs can be downloaded as trials

Animating stuff in Autocad is possible with the right add-ons, but is tedious and takes forever.
For visualizing a mechanical linkage it's hard to beat a parametric solid modeller such as SolidEdge. In SE you design each component individually, then define an assembly by specifying how each component is connected to the next. If you leave a few constraints open on the assembly, you can just click and drag any one component and the rest will follow it through the actual motion of the linkage, checking for interference along the way. Changes are then made by changing the key dimensions you specified in drawing the parts, right in the assembly in real-time. 2D drawings can be generated and updated automatically. It's an incredibly efficient way to work, but the software is too expensive for what you're doing and it requires some substantial computing hardware.

[yipster]

thanks for that info marshmat, i was looking at cathia again but i understand you feel solidedge is the way for this.
havent had my hands on it yet and have to mention i often wonder how you guy's keep up with testing all this software
i did a lot of hierarchy linking etc in 3d max but dont think its to learn in the 1 mnd demo, it works with dxf iges etc but is not an enginering platform.
sometimes i fade into happy memories how the first 3d dos programs started doing those miracles, have to keep up tho

[yipster]

geez, right, had some lessons and see i have the autodesk inventor educational CD still laying on this desk for months...
ok, ok, i'll instal and see how that works