Is CAD essential to all teams?

FIRST General Forum
1

A little preface:

So my team in the transition phase of trying to reach a level of “legit-ness” for next season. Over the past three years, we have been a group of kids that have turned out a robot each season, but with real struggle and a lack of planning. We usually have an idea of our general design, but almost all of the specifics usually happen somewhere along the way. The point being that we end up working very long days and stressed till the last minute of build season.

Is CAD the next needed step in order for us to become successful?

Our team currently has absolutely no background in CAD. And also no mentors. If we were to decide to use CAD next year, I would have to learn the software from scratch and then teach it to members in the off-season of next year.

The other option for us is to have hardcore designs/drawings on paper. Would that be sufficient?

2

It is not required; however, it helps a lot if you can use CAD effectively.

FYI, this is the first year MOE has a CAD model of the robot that was used for a majority of the design.

There are many resources available, but my go-to is YouTube.

3

You will need some cohesive, specific design if you want a world class robot. When my team has put CAD into the backseat of design, we fail. Now, as you point out, paper is perfectly acceptable. All you need is whatever works for your team, and stick with it. CAD is just extra convenient because you can import common parts. I would ask design or shop teachers if they want to help. Even if they can’t help directly, they might be able to have a class with CAD.

4

I would say it is and is not essential. Personally being a certified solidworks user since the beginning of 2014 i would say its the easiest to learn. If you do it well enough you can have the basic design and parts list done and ready to order. It helps a lot with knowing what you are going to build if you have a design for it. Best of Luck

5

The answer is, no. You can build highly effective robots without CAD. It depends on how you build your robot. When I first started, we used chopsaws and hand tools. We didn’t need CAD, just simple hand drawings. Now that we use CNC driven equipment, CAD is a must.

6

I think it really depends on your budget, both time and money.
In terms of time, working with new designers is CAD takes a lot of time. If you don’t start designing early, it will take longer to design than to simply do. If you don’t own a mill, why design things accurate to 0.001"?

I do highly recommend learning CAD purely for figuring out linkages and geometry, however. That’s something easier done on a computer than by hand. I would avoid paper simply because it’s more hassle for students than CAD in my experience. 973’s RAMP has some good videos on it.

All that being said, your robots already look incredible! I think for the build quality that you’re at right now, CAD could really help you get things more cleaned up, but it’s not necessary. More important than CAD and design is good strategy.

If you do go the CAD route, a small mill will help you machine parts that are very accurate, so you can get more utility out of CAD.

7

I agree, it is an added plus if you do use it. We have been using CAD for the last few years that I have been there, and this year we had very little CAD due to student commitments. We noticed the difference and did enough for the critical parts to make sure the design functioned properly. We have some new students that are interested in CAD now, and they are learning now (just because the competition is over, doesn’t mean learning is over).

As far as “no experience in CAD”, it is never too late to learn. Our team switched from Java to Labview two years ago, none of us knew how Labview worked. The students and I learned together as a team in the off season, and has strengthened our student/mentor ties. If you have dedicated students that want to learn CAD, do not be afraid to start with them and learn together.

Remember that this is all about learning and what they want to learn. Even if you don’t use CAD, you will still have a robot either way.

8

I do believe it essential that every FRC team should do some CAD. I am design lead on a somewhat low resource team and without CAD I don’t know where we would be. CAD allows you to simulate mechanisms and find interference long before you start to build them. It is critical for designing things with low tolerances (think about keeping things within 15in of your frame perimeter or figuring out the necessary dimensions for a scaler).

Also, CAD is nice because you can easily do it outside of the workshop. My team has very limited meeting times,so I do most of my CAD work at home. We then get to spend our meetings manufacturing.

This year, about a week after bag and tag, we decided to modify our robot into a defensive shield thing. Although the robot was in the bag we were able to figure out (using CAD) a way to attach a extendible 70 inch wide 54 inch tall shield to bumper supports already on the robot. It took less than an hour to attach it at competition because we knew exactly every hole that had to be drilled and bolt that needed to be put in. There is know way we could have done that without using CAD.

Engineering drawings can be useful but you CAD in general is much easier and simpler to use when it comes to mechanisms. My advice is to find a CAD software and learn to use it. Try designing some robots this offseason and post them here. You will get great feedback.

9

Saying CAD is essential in order to reach “the next level” is quite vague. There are many things that can be done in order to successfully have a 6 week build season but it starts from the ground up. Having the skills to CAD itself can help significantly, however it does not mean you will be successful. A good example of that is our team’s robot in 2015. The entire robot was designed using CAD; however we failed to prototype effectively which ultimately lead us to believe that we could do more than we could.

If I could suggest one key aspect to build season that most teams should be capable of doing, it would be prototyping. Prototyping not only allows you to determine which mechanism would be best to solve that year’s game problem, but it also allows you to refine the idea until you have the best iteration of it. If then, you would like to CAD the prototypes and integrate them into one large robot that would be ideal, as you would find any integration problems before you reach your build phase. However, please realize that if you begin to CAD without any preliminary model to base your designs off of, it will be extremely tough to have a successful build season as there may be problems that occur once you have built the CAD model of your robot.

10

No, it is not. 624 took a break from CAD in 2009 before returning to it in 2016. If you don’t have any experience, it’ll take time (maybe 2 years, one for you to get trained in a software of your choice and then another offseason to train others and develop an organization process - there are lots of resources to help with this, specifically 973 and 1114 have some good things to look at on their YouTube channels) to build up a system of using CAD effectively, so in the short term it will probably be better for you to stick with paper and pencil drawings with extensive dimensions. But eventually, as your team grows, your systems become more complex, and your resources expand - CAD will become a very useful tool for you to unlock a lot of potential.

11

Let’s take a wider look at the question.

CAN you make a competitive, impressive robot without CAD, and still inspire students to pursue a career in STEM? Yes.

However, I firmly believe in not only inspiring the path into STEM, but also sending students armed with as many useful tools as possible. If you were to try to take a product to any reasonable production team on a napkin sketch, or even a simple paper sketch, you wouldn’t get very far (excluding companies with drafters/modelers on hand for precisely this).

12

What would you suggest as a good balance time/resource wise between CAD and prototyping. We usually put a lot of time into prototyping but then we never put it into CAD to make sure it can fit with everything else. That hits our number one problem where our robot looks less streamlined and more cheesecaked than it should.

13

Not necessary but highly useful. One tool that I will be using next year to help teach our freshmen cad is 1114’s solidworks tutorials.

I binge watched them all one night and found that they would be extremely useful in teaching new students CAD from the ground up.

14

CAD is definitely a useful tool, and through FIRST you can access the industry standard programs with a ton of packages available for no cost to you or your team. Learning CAD can be a daunting task, but the best way to go about it is to download the program, watch some tutorials (973 RAMP has good videos, so does the SolidWorks website), and do a lot of CAD. You can only get good at the program by using it a lot. If you want to learn CAD, my best advice to you is to just design a bunch of stuff, and once you have a better idea of how productive you and your team are with CAD, you can make a more informed decision on whether or not to use it during the build season.

EDIT: I personally believe that, if you use CAD productively and efficiently, with sensible designs, it is a fantastic resource, and for teams that want to “take it to the next level,” CAD is not an absolute necessity, but it is definitely encouraged.

15

It definitely helps any team out, as it can save lots of valuable build time to have a step by step plan with all dimensions laid out, especially if there are a lot of intricate mechanisms in place that must be accurate.

However, one mistake a lot of teams make (ours included) is using CAD instead of actual prototyping, which can create a lot of headaches after the parts are actually manufactured.

Also, in regards to actually learning the software, everything about it is surprisingly intuitive and you will be surprised what you can make. I recommend designing simple assemblies at first and practicing all constraints to learn how they work, then tackle something like designing a previous year’s robot to practice for the actual build season.

16

No. I have watched CAD use go from 0% to essentially 100% in the workplace over the last 30+ years.

The skills needed to design a superior mechanism or to develop a superior strategy are different from the skills needed to make CAD drawings. As Asid and others have said, having the ability to do CAD will enhance your teams ability to develop superior mechanisms and strategies. Being able to use CAD tools is like being able to use a piece of word processing software such as MS WORD. It does not mean that one has the writing skills of Shakespeare or Hemmingway.

An example of this would be to draw a simple profile of your robot and “drive” it under the Low Bar to make sure it really fits.

In addition to using tutorials on YouTube, it would be best to supplement that with some “CAD Mentors”, even informal ones. I was asking one of my co-workers for tips on how to do specific things in SolidWorks. He would email me sequences of screen shots and I would pass them back to our CAD team. It saved them hours of time.

17

A few thoughts:

  1. I’ve hung banners with thoughtfully-designed robots done with a measuring tape, angle and box aluminum, and pop rivets. I’ve had well-CADded and waterjetted robots miss the show. There’s no magic bullet here.
  2. Knowing your fabrication resources is instrumental to making any CAD work. If you can’t buy or lathe a shaft to fit an application, you shouldn’t be putting it in the drawing! If your machine shop’s tooling has a minimum radius on cuts, make sure your lightening pattern’s corners have at least that radius! Start this conversation now, and do some smaller-scale tests before betting the farm.
  3. Part of legit-ness is having time to practice driving. Can you turn around a drivetrain that fast, and is it that much better than the kit drivetrain (or the kit drivetrain with some bolt-ons)? Do you have means to keep old robots together and running so the drivers can get some stick time in before this robot is together (and some time against defenders afterward)?
  4. Another highly underrated part of legit-ness is just not dying. Did your robot break down this year in a match? What happened there, and how can you fix it on the next robot?
18

CAD is merely a tool. When used in effective combination with prototyping and effective game analysis it can help to raise your capabilities.

Designing a robot completely within a CAD program will allow you to see issues and interferences in 3d space that you may not have accounted for with a design in your head, or even on paper sometimes. The more detailed the CAD model, the less likely you’ll run in to these type of issues while building.

To make full use of these advantages requires a slight change in thinking (in my opinion). While simply building things in a computer may not feel like much is getting done, by properly planning out where everything is going to fit, it reduces the time to put everything together. This might mean you don’t have ANY parts for your robot for week three (or later sometimes).

The other thing that needs to be taken into account is the manufacturing capabilities of your team. If you don’t have access to a mill (manual or CNC) you may have to account for the lower accuracy with which a part can be manufactured. If you have a sheet metal sponsor, you may be able to have parts cut and bent to very high precision. These issues are the ones that are often most difficult to account for. (Can’t tell you how many times I’ve thought of a design that would be difficult/impossible to manufacture given the facilities and resources of the team that I am working with).

CAD is just a part of the equation, though arguably a big one. Being able to effectively analyze the game (to pick the right mechanisms to build), and prototype effectively (to verify your “theory” designs work in the real world), also play a critical role. Can you build an effective robot without CAD? Definitely. I do believe that becoming more proficient with CAD will tend to increase the consistency of robot builds year after year (meaning fewer of the “our robot didn’t do what we wanted” years).

The other posters in this thread have provided some excellent resources to get started. Just digging in and messing around with the programs is a great way to learn.

19

The real answer to your question is: to take your team to the “next level”, you need to start working through a proper engineering process.

You can build a robot by assembling the Kit of Parts and then spending the next six weeks trying to improve it. “Ooh, I have an idea!” “Well, that didn’t work.” “Ooh, I have another idea!”

However, this is not engineering. This is hacking.

Engineering is a disciplined process. There are various definitions, but one I found on Wikipedia lists these steps: research, conceptualization, feasibility assessment, establishing design requirements, preliminary design, detailed design, production planning and tool design, and production.

For FRC, that would look like:

Research/Conceptualization - what is the game? what are all the possible things a robot could do? What are the offensive actions? What are the defensive actions? What are the point values of each? What are the cycle times of each action? What can be done in a 2-minute match? In a 3-robot alliance, how could each robot contribute?

Feasibility Assessment - Of all these things that could be done, what are the easy things? What is harder? Is a harder task worth it? This starts to take into account your team’s level of ability and available resources. For example, climbing is a hard task. Maybe it takes 20 seconds. It’s worth 10 points. Are there other actions you could do in 20 seconds that could score the same, such as scoring two high goals or damaging the fifth defense?

Design Requirements - Based on all the above, choose what you are going to focus on. Lock this down early to prevent scope creep. For example, we decided early on that our robot would be low bar capable, would shoot low goals, use vision assist for an autonomous low goal mode, be FAST, and be able to handle all the ground obstacles. It was tempting at various stages to try to add a climber, high goal capability. a sally port door opener, etc. But we knew we didn’t have the resources to build a Swiss Army Knife on wheels. We kept our focus on the design requirements we agreed on, knowing that if we had time later, we could go back and iterate.

Preliminary design - brainstorming, napkin sketches, prototyping. Now you have a rough idea of exactly what you want to build.

Detailed design - now you nail down exactly how the mechanisms are going to be built, their dimensions, weight, cost, etc.

Where does CAD fit into all this? It helps you with the design stages, and it forces you to actually DO the design stages so you’re not tempted to jump right into the shop to start cutting metal without first having a plan. Plus, it is a tool to help you with those design stages so you can play with dimensions and designs without committing to building anything first.

20

Typically we only dedicate a week to prototyping. However you can always give or take a couple days from that time period depending on the complexity of the game. If you are able to outline clear constraints and variables during the first day or so of build season, you should be able to complete the prototyping phase in about a week. This allows you to have a good amount of time left over to CAD.

Ideally, because you stated that your team is not familiar with any CAD software, I would suggest conducting workshops over the summer, even indulge yourself in a mock 2 week build season where you prototype and CAD a robot from a previous game over the summer. This will help you familiarize yourself with how tight the process can be and if it is feasible for your team to conduct during build season.