Re: Is CAD essential to all teams?
 

My opinion is that CAD is a communication tool.

CAD helps you lay out your ideas and communicate them to other team members. CAD helps you better communicate your ideas to the more logical part of your brain and flush these ideas out in more detail. CAD will help you communicate to your manufacturing team exactly what parts you need made and communicate your assembly team where those parts go.

CAD, however, will not take bad ideas and turn them into good ones. CAD won't make up for deficiencies in the other areas of the team you're trying to communicate with. CAD won't make a plan for you, just give you a method to better communicate your plan to other.

Also, learning to CAD will not teach you to design. Just because something looks like it will work in CAD does not mean it will turn out the same in real life.

Re: Is CAD essential to all teams?
 

In the past two years, my team has been working to get more CAD involved in our build process. I think that if you have the time, it is an extremely valuable tool for anyone on the team to know. If a student on our team learns CAD, it allows that to articulate their ideas better, and they become more engaged with the design of the robot.
One thing that I think is very important to keep in mind is that CAD skills != mechanical design skills. CAD is not a silver bullet that will transform your team into a powerhouse. Learning it has been fun and allows people to experiment with geometries and apply their design skills in a way that could not be done on paper. It is an amazing tool for robot design, but even the best tool in the world is useless unless the person using it know what they're doing.

Re: Is CAD essential to all teams?
 

Is CAD essential to all teams?
No, but neither are power tools. Like power tools, it can provide improvement if used properly. The free to teams software, all, provide decent tutorials.

Re: Is CAD essential to all teams?
 

Organization, money/sponsors, mentors/teachers, and disciplined processes are all necessary to reach a high level. CAD, used productively, can move the process part of the equation to another level. CAD allows one to express ideas accurately, to see if the ideas fit into the whole and to communicate the design to helpful sheet metal and machine shop sponsors. And CAD is THE way it is done in the professional arena.

Even 2D CAD is helpful but being able to animate 3D CAD is the holy grail. Accurate animation lets you try out the geometry of basic designs w/o wasting time building them. Nothing is more demoralizing than building a elegant piece of the robot only to find out it does not fit, is too heavy, the ball does not fit etc.

Re: Is CAD essential to all teams?
 

How soon is the CAD model done during the season? Or is it a continuous process where as soon as the CAD is done, the building of that part is undertaken?

Re: Is CAD essential to all teams?
 

For us, it varies depending on the experience of the members. Generally as soon as the drivetrain CAD is done we machine it, but we wait to machine other things until we are sure nothing will interfere with each other.

Re: Is CAD essential to all teams?
 

We're pretty much continuous CAD/manufacture.

CAD a part, built a part. Keeps us busy...

Re: Is CAD essential to all teams?
 

As a team that has more recently been designing in CAD as opposed to just modeling after design, the entire robot is extremely difficult to have finished in CAD before any manufacturing begins. Prototyping still needs to be done early on (and continued for several weeks) and the overall strategy/design still needs to be laid out before any serious CAD work can begin, since you can't really just CAD something without an end product in mind.

For the first time, our CAD team this year was able to have the design (mostly) modeled before the final manufacturing began (after about 3 weeks). However, we continued to work on resolving issues throughout the remainder of the season using CAD, whether that was by creating new parts to resolve rising problems, or by providing information to other sub-teams.

As for the team itself, it is rather difficult to get kids interested, but letting them know that all mechanical engineers use CAD, not a drill, as their primary tool can convey the importance of CAD. The team definitely does not need to be large; I've found that any number greater than 5 directly working on a CAD project can be counterproductive. This does not mean, however, that there should only be 5 students capable of CAD on the team. I recommend training as many people as possible, if only to provide them with the basic tools of engineering.

Re: Is CAD essential to all teams?
 

It depends on how you are making your parts and what your resources are. This year we acquired a sheet metal fabrication sponsor on top of milling and turning ops we already had access to. Anything we wanted done in sheet metal needed to be sent off in one big order as based on the lead time we wouldn't have parts we sent of later back in time. The milled/turned parts could be made almost on the fly and get back in less than a week so we were able to iterate more with those.

It all depends on your specific situation. And you don't have to use CAD to make a complete 3D model of the robot. Even dimensions on a 2D sketch overlaid on to the kit chassis model can be a very valuable tool during fabrication.

Re: Is CAD essential to all teams?
 

Yes!

If one cannot communicate the design to others on the team, the design becomes unmanufacturable by anyone other than the person who drew the design. This usually means making manufacturing drawings for each and every non-COTS part.

We had two team members doing the CAD work on our robot this year. One of them covered the drivetrain, utility arm and collector mechanism. He spent many hours cutting all the parts for the drivetrain and utility arm on the team's mill and CNC router because he was also the only one on the team that knew how to use those tools. When the CAD of the collector was handed to other team members, he had to pull up his CAD and give them all sorts of dimensions for the lengths of the tubes and the locations of the holes. When they did not have a particular dimension, they either guessed or stopped until they could ask him for it.

My son did the CAD for the upper structure/bumper supports. I insisted he make manufacturing drawings for all the parts he created and post them on the team's Google Drive. Due to his school schedule he could not attend all the meetings. The manufacturing drawings allowed other team members to cut them out and drill all the holes without him present. Ultimately, he only put in about 10% of the effort needed to manufacture those part and only because no one was available to do the work on the day he was able to go to the build meeting.

Re: Is CAD essential to all teams?
 

In my opinion, even if you're not going to use CAD to print drawings and manufacture off of the drawings, you should at least do 2D prototyping with the drawings. It's WAY faster to iterate on the computer than it is in wood, especially when it comes to getting the right cylinder locations, appendage movements, and even drivetrain when looking at going over obstacles. It helps you determine just how much ground clearance you need to put in.

Re: Is CAD essential to all teams?
 

You can get rid of many of the configurations that have no hope of working without having to spend the time and effort to prototype them. You can then focus on prototyping the ones that have a good chance of working.

Re: Is CAD essential to all teams?
 

CAD is not essential. As others have said, it is a tool that can provide a lot of benefit in the right hands. In the wrong hands, it can give false confidence in a design that is not practical.

Currently, the design process we try to follow boils down to:

1. Defining requirements - These should be S.M.A.R.T.
2. Basic 2-D mock-ups - This can be a sketch in CAD, a linkage made out of cardboard, whatever we can do quickly to get the basic geometry worked out.
3. Prototyping - This can help narrow down designs if multiple 2-D mock-ups showed promise. It also gives us a chance to test things like ball compression or grip material.
4. Basic 3-D CAD model - This is detailed enough to build a full working version of the mechanism, but usually missing things like lightening patterns. If we're unsure about mounting points, the model may contain an array of holes that we can choose from when assembling everything.
5. Initial integration check - Before cutting metal, we like to make sure everything will fit together, at least on a high level. Sometimes this only happens as blocks in PowerPoint, other times it's a full 3-D model.
6. Revision 1 mechanisms - These generally become our practice bot. There are always things to be learned by actually assembling and testing everything. We try to get these done with enough time before Bag Day that we can iterate on them at least once.
7. Iteration cycle - The learning from revision 1 gets integrated into the CAD models, and when we feel that we have something we can put on the field at a competition we begin manufacturing revision 2. Inevitably, over the course of the competition season further improvements become apparent. We try to keep our CAD models as current as possible as the season progresses, in case additional parts need to be manufactured.

The farther along we get in this process, the more value we get from having an accurate 3-D model of the robot. This year, after our first event we decided our pickup wasn't robust enough, so we made a new one for our second competition. That iteration lasted through two events, but it's showing some wear. We're currently planning another iteration for Championship. Having a CAD model has allowed us to plan out these improvements without direct access to the robot.

Re: Is CAD essential to all teams?
 

Legitimacy