@ShayaGhanbarwrote:
@Anonymous here is what I am looking for:
https://www.youtube.com/watch?v=QKezL2zSvKU
Do you think that this is possible with contacts?
Thanks!
Hi There
I can't say as I can offer anything particularly helpful to this but I do have an observation and it would be interesting if anyone else has an opinion on this.
I came to Fusion as a Sketchup user (blasphemy probably). Sketchup had an old user built joints plug in called SketchyPhysics which was later updated (brilliantly in my opinion) by another user called AntonSynstria and renamed MSPhysics. What MSPhysics lacked in comparison to Fusion's joints (polished, professional implementation etc) it made up for in what I can only describe as analysis tools. It is hard to describe but basically you were able in MS Physics to see the geometry behind the joint plug in, this make sense in relation to Fusions contact sets because you could see the geometry that the contact was calculating a reaction to.
This is really hard to describe to but I think it may be relevant and worth documenting for someone using contacts sets in Fusion. What MSPhysics would do is calculate the 'bounding box' of the contacting geometries and attempt to resolve their reactions using physical rules. So for instance if I had a spur gear on a gear rack and I created the gear or rack bodies as a single entity with n number of teeth then the plug in would do its best to resolve this as a geometry. Since the software needed to constantly recalculate this the simulation would soon fail because it was just unable to resolve the physical interactions of two complex shapes in real time. However if I created the gear and rack by creating each tooth as an individual body (ie create one tooth and make an array of n number of them) then the simulation would work no problem because the geometry of the tooth made sense to the plug in. I was able to work this out because the plug in had an option to turn on the plug-in's view of the geometry.
I don't know if the above makes sense but I have noticed that I can get contact sets work fairly well in Fusion by breaking up the geometry into distinct bodies (more accurately components), that 'make sense' to the software. In your example above I guess that would mean breaking up the pin slot body (component) into two. One would be a grounded rectangular block with a flat face on which the pin would have a planar joint. The other would be the pin slot component which would be a rigid group with the rectangular block. If you then create a contact set between this and the pin component then the pin component will move in the pin slot as you would expect. It
In my case this works with no issue and does not load the CPU. I think that this is because the two geometries are separate and it is easy for Fusion to work out the needed simulation. If the pin slot body were one component then perhaps this would be different. I can't really say if I am talking nonsense here because unlike MSPhysics I don't have the visual representation of the simulated geometry to see what is happening but I can say that I have had some degree of success making unsuccessful contacts sets work with this method.
What would be great is if someone who knew how contact sets make their simulations was able to help us to clarify this or even better if they were able to look at MSPhysics and see the advantages of that approach.
So an indirect answer to your question is (in my opinion) yes this would work with contact sets but possibly only because I have no idea what I am talking about.
