Do we need CAD drawings.
You are not required anywhere in the rules as a general rule to have CAD drawings of your robot. Sponsors may ask for them, however. For example, 2220 is sponsored by PTC, who asks for updates and CAD files of our robot every year.
CAD drawings are not necessary, but it can be very useful to create a part in the program so that you are able to visualize the piece. It can also be referred to if you CAD the whole robot exactly, for mesurements and the BOM, although getting that degree of acuracy can take some time. And some teams may not have enough man power.
That’s so true. Especially for working on the BOM - definitely saves time to have a visual reference at your fingertips.
Also, having CAD drawings can be very useful when talking to judges, pit scouters, and other people interested in learning about your robot. This comes into play very well during competitions when the robot is being worked on and parts of it are out of view. I also noticed that having a CAD drawing to look at helps me explain how things work on the robot. I’m not sure if this is true for everyone, but the drawings are still useful.
All in all, as was stated earlier, CAD drawings are not explicitly needed, but if you have the time and ability to make them, they can really help.
I hope this helps,
–T. K. “JankyWinduist”
You are not required to have CAD drawings, nor do you need to use CAD to design your robot.
Cad drawings are not required, but I see this as part of the whole “inspiring technology” thing that FIRST is about!
We model our robot in Inventor as we are building it, and create/print drawings for machining parts.
Before we cut up too much metal right after kick off, we have the basic model created which we build on. We try to have the “big stuff” on the model so we know what we’re bulding. This is a huge help for checking clearances, making brackets and motor mounts etc. It also helps with explaining things and visualizing.
The bottom line is, in real-world engineering, drawings/models are designed and created before things get built, and so should we… if you have the ability (IMO).
Makes it much easier to see what you’re building before you build it…
You do not need CAD to design or build a robot. We use it pretty religiously. We find that generating a CADD model in inventor before building the robot saves us a lot of time and money, and we end up with a better looking robot. We can also eliminate kids who miss a lot of meetings walking in and not knowing what is going on, or why things are the way they are. If a kid misses meetings, they can just consult the CADD files, and look at the robot. Comparing the two they know what needs to be done.
There is also something really nice about knowing what to buy, and how much of it you need. We have saved a ton of money this way. Before CADDing our robots we would literally guess about what might work, spend money, and then find out we were wrong after modifying the part in some stupid way so that we couldn’t return it. Our first year cadding the robot I could have told you how much money we would spend total and have been right within about $100 during the second week of build season.
Here is a video:
http://www.youtube.com/watch?v=HU3_N_emoks
Hope this helps.
Edoga
While CAD drawings and files are not a requirement, they can be of great use to teams that implement them correctly. Some of the benefits of a CAD drawing for our team are as follows:
- We can “prototype” to check geometry and configuration without needing to spend both time and money building something. Last year we planned to climb on the inside of the pyramid but an astute student found a major geometry problem that would have prevented us from competing before we had even started on our climbing mechanism.
- Modular systems are much easier with robots designed in CAD. If you plan ahead and get a drivetrain designed immediately (after discussing pros and cons, of course) you can design the rest of your components around a central base that may only need minor tweaks to work.
- It gives students looking at a career in engineering valuable experience and a head start on becoming certified in a program such as Solidworks. I know that I plan to take the Solidworks Associate Certification test this coming May and don’t expect to have too much difficulty with it.
- It gives you exact dimensions to reference and look to when fabricating parts. This helps to prevent mistakes and gives you the ability to (using Solidworks or another similar program) create a drawing file that has all the needed reference dimensions labeled to take to a machine with you.
- Having CAD files, both for individual parts and whole robots in an assembly, is a large boost for presenting to both sponsors and the community. It helps to show just how much time and effort you put into this robot and gives you something you could give to a potential sponsor on a flash drive for them to see exactly what you do even after you’ve finished your presentation.
These things being said, designing an entire robot in a CAD program is a large undertaking and my team splits the build season accordingly. Our mechanical sub-team spends usually about the first two weeks making mechanism specific prototypes and modeling the entire robot in Solidworks. We then attempt to spend the rest of the build season fabricating and refining our designs while a few people help with updating the CAD model to reflect changes we have made during testing. It’s a system that works well for us.
To help get you started with CAD Drawings, you can go to our FRC Drawing tutorial here. Review Unit 6 Manufacturing and Parts and Unit 8 Teamwork tools.
In SolidWorks, you usually begin with the 3D model of a part, from there you make the part drawing. You combine parts to create an assembly, from there you create an assembly drawing. Unit 8 Teamwork talks about the very important “pack and go” feature to keep your part, assembly, and drawing files all together. This is very important.
One of the other things that is helpful is to create an additional column in your drawing Bill of Material that uses the parameter “Cost”. When “Cost” is set for each part or assembly as a parameter individually, that parameter is shared by the drawing. You can sum up the Cost in the Drawing Bill of Materials to get Total Cost.
Also with Assembly Visualization you can sort by Cost to determine which parts cost the most. You can also use the same process to sort by Mass, to see which components are the heaviest.
Drawings and CAD models are not required for FIRST, but they also help document what you did for next year’s team and to present a professional porfolio of your robot design process. Be certain to create a good title block with the correct units, school name, title, and revision. Don’t get sloppy here.
I also believe drawings, if done according to an engineering standard, are valuable to the person on your team that has created them for the ever important job interview. One of the most popular SolidWorks certification exams this year is our SolidWorks Advanced Drawing Tools. Our commerical customers create drawings.
Good luck in the competition. Marie