Close

Still Fighting Autodesk Fusion 360

A project log for NanoEgg Music Synthesizer

A powerful little music synthesizer with a classic look!

t-b-trzepaczT. B. Trzepacz 08/16/2016 at 19:490 Comments

Parametric modeling has so very much promise. Change a single value and your whole model updates perfectly! What's not to love!

Lots.

So it is unfortunate that none of the software I've been able to try works reliably. I'm still fighting with Autodesk Fusion 360, and while it is nice in many ways, it seems to be bad at recalculating all of the dependencies in a heavily parametric model. So bad that it will crash on a fairly regular basis. When it isn't crashing, it is deforming my model in strange ways every time I try to update a parameter. I can do a lot of rework to get one parameter to work, and then the next one still breaks the model very reliably.

The only real advice I have to offer is to avoid trying to use constraints to calculate your sketches. By all means, use constraints like vertical/horizontal, coincident, perpendicular, and parallel. But avoid using "equal" on a long chain of items to get the spacing right, or midpoint. Instead, use "Parameters" to calculate the position using your own math, and just add a dimension to attach that value.

Be aware that "Offset" will use the value of a parameter, but not actually refer to it until you click on the dimension for the offset and add the parameter again.

The only way to have a sketch refer to something on a sketch or another body is to do a projection. The latest update seems to do this automatically, but it still is the same thing. Use these sparingly, especially when projecting edges from bodies, as I've noticed troubles with them not updating. It is better to project from another sketch than from an edge on a body.

Constraints applied to a projected line do not seem to propagate backwards through the history chain, which can be very handy in forcing it to update correctly. You can make layers of sketches, each fairly simple, that proceed from the projected output of the previous layer. Again, less use of projection is generally better, but this is one place that it might help you get around the terribleness of the recalculation engine.

Also, test your Parameters by changing them often and making sure the sketches and model respond as expected. It is a lot easier to fix the constraints as you do them than have to walk back through the history and try to change things after the whole model is done. Easier, and less prone to crash.

I have learned all of these things, and yet I still keep making the mistake of trusting the software to work. I am a fool.

Discussions