An Onshape approach to everyone's favorite RC nitro engine

Рет қаралды 657

Ай бұрын

Today is a long, sometimes rambling, but hopefully interesting deep-dive into one of my favorite models. The OS MAX FX 46 nitro engine is verging on canonical in the CAD industry (just check GrabCAD for various incarnations). But I thought it would make a good exercise to build it natively from scratch, using some new (or just cool) techniques in Onshape.
I already realize I've missed a couple of things I really wanted to cover, so yeah I be following up (in shorter form!)
NOTE: For those following along my playlist, this one uses simpler/core techniques rather than some of the more recent explorations of curves and FeatureScript.
Starring: Expressions, Variable studio, multi-part modeling, linked documents, in-context, configurations, composite parts, named positions, exploded views, Render studio, BOM, Boolean, patterns, standard content, bridging curve, and more!

Пікірлер: 12

@oleksij-hd6qb Ай бұрын

amazing, thanks for the walkthrough

@gregbrown-onshape7555 Ай бұрын

Thanks for sitting through it! I know it was a long journey...

@johnlongphre3918 Ай бұрын

about 30 years ago, I watched an interview of the NASA Administrator. The subject was the problem of Math and Science Education in America. He basically said that if, in the 1960s, the entirety of his high-school education was centered around the Chevrolet 350 cubic inch V-8 engine, he himself would have paid more attention to his teachers, who, so often droned on about abstract concepts. I myself have owned several O.S.Max 46 motors (in previous decades), and I would pay for a course that takes me, start-to-finish, through this model, stopping to discuss in-context editing.... and named positions, how to organize the project, and all the sort of tips-and-tricks (why do it this way instead of that way, etc). I think a comprehensive approach is what is missing in OnShape education right now (everything is so compartmentalized it seems). Seriously, people would pay money for such a course, above and beyond all the stuff available on the OnShape Learning Center.

@gregbrown-onshape7555 Ай бұрын

Thanks for this wonderful comment - I’m with you 100%. I’d be happy to start a series with this engine and dig into those topics and more.

@nickholzem7401 Ай бұрын

Hey Greg, I like the method you show building the engine from the inside out. I have a question for named positions. After mating your assembly for motion how do you create the named positions with the parts at top and then bottom dead center?

@gregbrown-onshape7555 Ай бұрын

Sounds like I should do a quick demo of named positions. Watch this space!

@nickholzem7401 Ай бұрын

@@gregbrown-onshape7555I would be very interested to see your preferred method for establishing the positions.

@joshtargo2696 Ай бұрын

why did you use Move Face to finish the fuel tube instead of extrude? same result, but any other benefits of one over the other in that specific situation?

@gregbrown-onshape7555 24 күн бұрын

They will/can give different results as they are doing quite different things topologically. In my case an extrude would have worked, since the underlying sweep path was tangent at the ends. However in different situations, such as a simple arc, the move face and extrude will look quite different... The extrude will be by definition a normal direction from the end face, while the move face will keep the curvature of the side faces (thereby extending the arc) Here's a quick example cad.onshape.com/documents/b9b52e11d7266e5ed655ab50/w/77611edca52037d2e35267c5/e/9ed093d8a42d4ae0dbb4e479

@ckopack Ай бұрын

Hey Greg! Is this model public by chance? I would love to check it out!

@gregbrown-onshape7555 Ай бұрын

I just made a public version available for you! cad.onshape.com/documents/117ebf5924e35f3871c8e6d5/w/6ddb0cd91f2377e06e55ada6/e/665c31713a0909595ff09e24 There are some linked docs that you won't be able to open, but they are just to standard componentry that I don't really want to make public just yet. I think you'll find the Crankcase Part studio the most interesting anyway. If there are confusing things in there, please drop me another comment and I'll be happy to (try to) explain PS in the version I provided the carburetor is not complete. There is a neat sliding/rotating aspect which is only in my private version. I'll hopefully get around to updating this in the public one. (It took a bit of disassembly of the actual OS MAX-46FX which is sitting on my desk here to understand how it works!!)

@ckopack Ай бұрын

@@gregbrown-onshape7555 epic thank you I’ll check it out!