When and how do you create a whole-robot design?

[ohrly?]

Originally Posted by daniel_dsouza

After prototyping mechanisms (along with their detailed CAD), their compatibility is guaranteed by using standardized mounting techniques (gussets, brackets, axles, etc). Tolerances are handled in CAD, troubleshooted on the prototype, and built into the final.

We use standardized mounts like you, so they mount just fine, but I'm curious as to how you make sure they actually interact correctly. For instance, our feeder looked fine in the CAD, but when we tried it it flipped the frisbee almost every time, which turned out to be impossible to fix without rebuilding the feeder entirely.

Originally Posted by Chris is me

Our head mentor is currently (and probably will be for some time) our lead CAD coordinator, making sure all of the subsystems work well together before manufacturing... or after, if we have to. I think teams need one or two people to integrate everything successfully in CAD, with good communication skills so they can talk about the design with prototypers and subsystem CADers.

I'd love to know how your head mentor goes about coordinating CAD. None of our mentors are mechanical engineers (actually, none are engineers at all), so the students coordinate the CAD as a group of about 5. Does he set requirements/specifications before the CAD is started, or does he let them start and then facilitate discussion to avoid conflicts?

[Calvin Hartley]

We're usually done designing by week 7.

[Chris is me]

Originally Posted by ohrly?

I'd love to know how your head mentor goes about coordinating CAD. None of our mentors are mechanical engineers (actually, none are engineers at all), so the students coordinate the CAD as a group of about 5. Does he set requirements/specifications before the CAD is started, or does he let them start and then facilitate discussion to avoid conflicts?

We quite simply didn't have enough people that are skilled enough at detailed CAD design + system integration that management at the "end" of the process is a problem. I think we just used a Google Drive this year between him and the 2 other people doing full subsystems in CAD.

We have a fair number of first and second year students who know enough Inventor to draw up prototypes and make part drawings for those prototypes, but they're a little ways off from being able to do full subsystem CAD. This year for manipulator, the CAD workflow went from student prototyper -> a mentor (me) to touch up the details and integrate lessons learned -> head mentor to integrate the subsystem with the whole robot. Students were around every step of the way.

Once we're fortunate enough to have a larger CAD team (should be this season, we have a lot of promising sophomores who made real contributions this year), we'll probably move on to some more sophisticated version control.