Algodoo

Interesting tutorial, and very well done!

Just curious, why do you insist on fixating the circle to the background instead of gluing it? What's the difference?

gluing it can cause difficulties in the long run, like gluing things together. it's a suspected cause of the "shifties", where objects start moving around, even if they are not manually moved (bug). and, it can cause undesirable lockups of mechanisms. fixating is much more precise, and is less likely to result in these errors from my experience

I've read about differences between gluing and fixating in the forum. Some people say that you should never mix the two. That is, either use glue or fixates but never both because they can cause undesirable effects (bugs) if both are used. Some people like glue and some like fixates. I guess it's a matter of personal taste. I happen to prefer glue because in my opinion, fixates are ugly. And you are correct about the "shifties". Until I found out what was causing it, I just about went crazy trying to figure out why things were moving around that are supposed to be glued together!

Thanks!

Awesome. I've never seen or tried this before. Are you the first one to describe this technique?

I am not the original creator of near perfect epitrochoids, but I am the first to make them using this method, from what I can see.

My method can make any housing shape, including epitrochoids but also other radially generated shape. It also can make tracks for sliding mechanisms. This is more in-depth than my tutorial.

One thing: If you were to make 2 boxes, and put them on top of each other, and them add a fixate to connect them, when you try to add another fixate it just attaches the box on top to the background. It does not allow multiple fixates to make a "loop" with each other. Fixating two boxes together and then gluing them behaves like there are 2 fixates between the two boxes, making that bad loop where the glue then goes to the background instead of the box. Gluing works exactly like placing an invisible fixate.

I don't know, bit i still think that it's not too necessary to have a perfect epitrochoid for a wankel. the rotor doesn't touch the casing in most cases (in algodoo obviously) but it's ok anyways that you did a tutorial of this. I made them with a tracer, then made a polygon with the shape and ya, but I guess this is quite faster

Also gluing to the background/to another shapes is really bad since when you put a fixjoint and delete it, it bugs.
Also Xray, if you were doing mechanical things, then you'd understand why gluing is SO annoying! No offense, actually I like the variety of (at least a little) complex scenes in Algobox, and I appreciate people like you, Steve, lololoer and all our thymers here. but normally, when you're doing scenes with 100 parts or more (car bodies, and such) and you glue them, then you attach some premade thing to it with a simple fixjoint and delete it, you get a bug

I totally agree with The Linkage, glue together has caused me many headaches
It is easy to select all fixtates and make them invisible or
zoom way in and make them tiny in the first place
To make a complex thing like a bike frame use CSG and end up with
one single part instead of several parts glued or fixed together