Is CAD essential to all teams?

[sdcantrell56]

Hey there. We are in the metro area as well although not quite neighbors. Our robot is entirely designed in CAD before machining. Almost nothing on the robot was fabricated without a CAD design as well as design review with at least one mentor. Part of this is because most of our fabrication is by CNC equipment, but also because we don't like wasting material or man hours on something that won't fit or work properly.

Using CAD will absolutely help you. It will not; however, be a revolutionary change without the knowledge to back it up. I recommend the most important step you can take is finding at least one engineering mentor, preferably a couple with different skill sets. I might even know of one who wouldn't mind helping out sometimes (PM me for details). The next biggest thing is learning how to analyze the game and decide what the important tasks are and what are tasks that you can reliably accomplish with your resources. This one is tough because you have to realistically assess your teams abilities and resources. Trying to do everything this year was pretty much unrealistic for most teams, especially teams in Georgia. Not being harsh, just reality.

Would love to talk more about it, so feel free to message me. We can maybe even set up some time to come down to Westminster to see how we work.

[GeeTwo]

If you have a sponsor or in-house workshop that is just waiting on your CAD to crank out beautifully worked pieces, and you aren't CADding yet, then absolutely CAD should be on your short list of talents to develop. If your machining is done in-house on a drill press or chop saw, then you have a real question as to whether CADding your robot design would be an improvement. The bottom line is that CAD is a tool whose real value is dependent on your team's other manufacturing capabilities; your team may or may not be ready to improve its processes based on CAD.

[Sid323]

Originally Posted by abhishekmalle

Ok, ok. So I'm getting the general feel here. CAD isn't absolutely needed for a successful team and could maybe be postponed till we actually have a mentor of some sort.

To the teams that CAD:

-Is the entire robot done in CAD before the manufacturing process begins? Or is there more of a rolling system where the robot is built as the CAD is completed?

-How much of that aforementioned planning is actually useful or are you just going through the motions?

-How do you go about generating interest for CAD? At least at my school, people don't exactly turn their heads at the prospect of joining robotics to CAD.

-How many people does it take to have a reasonably sized CAD team?

To the teams that don't usually CAD:

-Do you still have the entire robot planned out on paper (including dimensions) before manufacturing?

-How much of that aforementioned planning is actually useful or are you just going through the motions?

-Are there any specific build season procedures that you go through that have helped you in the absence of CAD.


I just realized how many times I used "CAD" in this post.

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.

[Creepy97]

This was the first year that i was told that we CADed before we made the robot and from what i could tell we all knew what to do alot more than last year.

CAD is useful!

This was sent to me by one of my teams mentors for learning CAD on my own.
https://www.youtube.com/playlist?lis...theHaNQWxNA5yT

[ASD20]

It definitely is possible to learn CAD well enough for FRC in the offseason. As the design lead of my team this year, I had to lead the CAD of our robot and had no real CAD experience prior to last Summer (unless you count SketchUp). So, over the summer, I taught myself to use inventor. I learned a lot from doing that and I have a few pieces of advice on how to do this. I am not a CAD expert, but rather an expert on being a complete CAD rookie.

1. Make sure you have a project
It is really hard to stay motivated and interested when just following tutorials or CADing random things. I first started designing a button board and then a t-shirt cannon robot which we eventually built. Having a project gave me motivation and also a lot of practice and ability to learn from my mistakes due to the size of the project.

2. For FRC, you don't need to know what most of the CAD software does
95% of the parts I design are made almost entirely of circles, rectangles, and hexagons arranged in a circular or rectangular pattern. Most of the more complicated parts are COTS and you can just download the models. However, I will say the one thing you should learn as soon as possible is that pattern tools are your friend. Trust me, I probably drew 200 individual 1/4" holes spaced 1 inch apart before I learned about patterns. Assemblies for robots can be difficult and I still don't know a lot of the best practices, but that is something you should devote more time to because a lot of robot CAD is assembling COTS parts.

3. Learn as you go
I wouldn't personally recommend going through complete tutorials, though if that's how you learn best, don't let me stop you. However, I find it is best to work on a project and when you reach something you don't know how to do, then go and watch a short tutorial or ask somebody. I find this is a lot more efficient and you will also learn a lot just from repetition, especially in term of good practices for easy modification and assembly. In my early projects the last few parts are noticeably (and somewhat entertaingly) better drawn and organized than the first parts.

[orangemoore]

Originally Posted by ASD20

2. For FRC, you don't need to know what most of the CAD software does
95% of the parts I design are made almost entirely of circles, rectangles, and hexagons arranged in a circular or rectangular pattern. Most of the more complicated parts are COTS and you can just download the models. However, I will say the one thing you should learn as soon as possible is that pattern tools are your friend. Trust me, I probably drew 200 individual 1/4" holes spaced 1 inch apart before I learned about patterns. Assemblies for robots can be difficult and I still don't know a lot of the best practices, but that is something you should devote more time to because a lot of robot CAD is assembling COTS parts.

A good rule of thumb I follow is if you are ever thinking, "There has to be a better way" google whatever you are doing and I bet there is a better way.

[Monochron]

Originally Posted by abhishekmalle

but with real struggle and a lack of planning.

If your problem is lack of planning, adding another task isn't going to fix it.

[evoluti1]

Let's take a step back: the D in CAD stands for "Design." If you had asked instead, "Is design essential to all teams?", I think the answer is obviously yes. Whether you're a rookie with no mentors or an IFI team, you should do some amount of design before you start building.

So the real question is, "Is it essential for every team to design some or all of their robot on a computer?" First I want to qualify this: NO team should do ALL of their design in CAD. For instance, a large part of your design should be your
strategy for playing the game, and that's not exactly a task for Solidworks or Inventor. Also, CAD should not get in the way of prototyping - every year I see lots of robots which clearly took lots of time to model, but aren't effective playing the game because the underlying design idea wasn't refined enough through prototyping and iteration. In other words, CAD is just one part of the design process and should be understood and utilized as such. (Perhaps if you're wondering how to make your design more "legit" you should spend some time learning about how design iteration works and how the best teams use it, rather than just focusing on the CAD aspect).

That said, I don't think there's a team in FIRST that wouldn't benefit from using CAD software. To restate the question I posed earlier, we might ask, "in FRC, how does Computer Aided Design compare with Cardboard Aided Design or even Paper Aided Design?"

A lot of people say that CAD is difficult to use because it's harder to learn than doing design on paper. I totally disagree with this, at least I totally disagree with the notion that drafting by hand is significantly easier to master than CAD. Learning to use CAD effectively and learning to draft by hand effectively should both be viewed as large time commitments (it's why drafting used to be an entire high school class!). If you're currently making drawings by hand, but you haven't invested that time and effort, chances are almost 100% that your drawings aren't very good, and you should be investing serious time an effort in a new skill anyway. And if you have to learn a new skill, why not choose the one that's more versatile or applicable in your future career?

With the main drawback out of the way, what are the benefits of CAD over other types of design? For all but the simplest parts, I find that CAD is quicker than hand-drafting. Of course this is largely a function of how much practice you have. But again, if you're not practiced, drawing (well) by hand won't be very quick either. For more complex parts (even if you don't have access to CNC equipment), CAD starts to really shine. Parts that contain anything more than one or two rectangular profiles or square hole patterns quickly become more time consuming to draw by hand than to lay out on a computer.

But one thing a lot of people miss is that CAD isn't just about designing complicated parts with really cool-looking CNC-cut lightening pockets - it's really a tool that can improve any robot. For determining layout of an assembly, you just can't beat CAD, especially in a game like this year where lots of teams found it important to pack all of their hardware into a small space. In addition to 3-D assembly layout, CAD can also help you determine 2-D mechanism geometry before you even start designing any parts. This year, our team was confident we could build an arm that could tackle all of the defenses before the team versions were even finished, all because we could lay out the relevant geometry and constraints in an Inventor sketch. I don't know of a better way to do that kind of planning before you start cutting metal and spending money. (And in case I haven't beat the CAD-is-only-for-fancy-parts horse enough, I should mention that when the time did come to design parts for our arm, CAD helped us figure out how to make it work with only a band saw and a drill press.)

CAD is also more forgiving than drawing by hand. Mistakes can be corrected far more quickly (and often more thoroughly) than on paper. In fact, I'd argue that the ability to correct mistakes alone makes CAD an indispensable tool to have in your repertoire. After all, what is "design" but a process of repeatedly making mistakes in a controlled way and correcting them? Anything that helps you iterate faster is a good thing.

There are lots of other aspects of CAD that make it appealing and worth your time to learn, but if you do decide to pursue it, I think these are the main features that you will soon find indispensable. Like I said, I don't think there's a single team in FIRST that wouldn't benefit from being able to do high-level design and correct mistakes before it's too late. For these and lots of other tasks you simply can't do better than CAD.

[Knufire]

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.

[philso]

Originally Posted by Knufire

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.

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.

[Michael Hill]

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.

[philso]

Originally Posted by Michael Hill

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.

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.

[Jake177]

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.

[SamcFuchs]

legit-ness

Legitimacy