Quote:
Originally Posted by Andrew Lawrence
I totally get what you mean. I make sure that whenever we use COTS parts, everything is put in CAD and treated as if it were a custom part that we designed, sketched, extruded, mated, and assembled ourselves. The only difference between the CAD and the real part is that we buy the real part, we don't make all of it (though like in the case with the versatubing, we do machine parts of it ourselves, but all machining is already included in the CAD model). This method allows our students to learn as much as possible as if we designed the part ourselves, but still have the ease of use, reliability, and time saving advantages that a COTS component normally has, like Adam previously mentioned.
|
There's a world of difference between designing a part and drawing it in CAD and putting it in an assembly. You're just making models, not designing a part.
Perhaps this is pedantic but I would also say you are not "designing" a drivetrain when you take COTS parts, decide how long four pieces of tubing should be, and then put them together in a preconfigured pattern. It's like saying building a Lego model from the instruction book is design. About the only design work being done is the choice of gearbox, wheels, and gear ratio. That's not to say COTS is bad or whatever, but using the VersaChassis isn't exactly the same as designing a custom drive at all.
--
What is right for your team depends on your resources. Basically, do you have more money or more design resources? Most teams have not enough of either, but money is way easier to get more of than design and build resources. I agree with others who say that focusing design effort on the manipulator and sticking to COTS drives is a general good idea. However, it depends on the team. In the off season, you have a lot more freedom to experiment with new ideas (and usually, less money to spend), so working on custom drives is a very good idea, even if you stay COTS for another build season or two.
There's no universal right answer, there is no single optimal solution. Nothing one size fits all. Asserting facts as such is probably a bad idea.