CAD?

[atucker4072]

Definitely start learning as soon as possible. You do not want ro start learning during build season. You can use any program you want to. We have used inventor in the past however we switched to CREO.

[Chris_Ely]

One thing that I have found is that knowing how to use CAD software, and how to use CAD to design is a big difference. I have seen many students model something in CAD that would be very difficult or impossible to actually make. Be sure that the people on your CAD team know the manufacturing capabilities of your team (i.e. sheetmetal, 3D-printing, extrusion frames, etc.).
Also, make sure that you have a computer that can run the software. For best results, you will want a full workstation built specifically for CAD, which can get expensive. However, for FRC type stuff, you can get away with lower cost consumer computers. Fast processor, dedicated graphics, and a good amount of system RAM are important.

[Kingland093]

Like what was said earlier, start practicing now! It will benefit you enormously!
My team uses PTC Creo because we have mentors who know it very well and you can get it for free from PTC. They also have pre-modeled parts including the entire KOP drivetrain which was super helpful for us this year because we could immediately start designing ball mechanisms.
My team had me and one other person on CAD this year. It didn't work out to well because I also do programming so I had to be in 2 places at once most of the build season. I would recommend having about 3-4 people who know CAD very well, maybe more depending on your team's size. It's very important that they work very closely with your robot design people.

Hope this helps, and if you have anymore questions feel free to ask!

[julianpowell]

Originally Posted by Kingland093

I would recommend having about 3-4 people who know CAD very well, maybe more depending on your team's size. It's very important that they work very closely with your robot design people.

Ideally your design people are the ones CADing. After all, CAD is a tool for designing.

[Joe195]

I'm glad you guys are doing this! As said practice is a must. Going on to programs, Inventor and SolidWorks in my opinion are the better programs, but SolidWorks is used in industry much more. Since you are starting from scratch I would advise to use SolidWorks. Once you have that, I would also recommend sectioning off members. One good idea is to have people to design and other people for doing prints for manufacturing to split up the work load. Only have two or three people max actually DESIGNING the robot though. Mentors will always be with them discussing design solutions, which can make working with more than 3 students very hectic

[cadandcookies]

Originally Posted by julianpowell

Ideally your design people are the ones CADing. After all, CAD is a tool for designing.

I would go as far as to say that you have to make sure your design people are invested in using CAD before you start using it for the build season. In 2012 and 2013, my team's design and CAD groups were separate, and it caused nothing but pain for both parties.

The end of the season is the perfect time to start building your CAD/D team-- you have plenty of time before next season. CAD is not something that can be learned effectively overnight-- it requires patience and effort, like any other skill. A lot of kids are intimidated byt the steep learning curve, but I personally think it's one of the best technical skills one can learn on a robotics team.

The other thing would be, as Eric said, efficient parts design. Your designers should be intimately familiar with the contraint tools of your program of choice-- both sketch constraints and assembly constraints. Good "model intent"-- ie, designing for changes-- is key to having an efficient CAD team.

If your team does not have good model intent practices, to quote the immortal words of South Park, "You're gonna have a bad time."

[cxcad]

Communication with the build team is key. Otherwise, there will be two very different robots, one physical and one virtual.

[artdutra04]

Develop a system for part numbers and revisions and stick to it.

Never use names like Intake Left Arm Outer Side Plate 2.sldprt as this makes it very difficult for BOM and PDF drawings when you send parts to sponsor machine shops. Names like 2014-110-001_Rev1.sldprt or 2014-110_Rev8.sldasm are much better and better prepare you for how companies in the real world work.

Don't be sloppy on your modeling. Constrain ever sketch entity - if you open a Solidworks sketch there must never be any blue lines.

Don't use project/convert geometry from an assembly into a part. It's great and fast when it works the first time but when you iterate and change designs it will be a minefield of broken references that will take for ever to fix.

[Dival]

Originally Posted by artdutra04

Develop a system for part numbers and revisions and stick to it.

Never use names like Intake Left Arm Outer Side Plate 2.sldprt as this makes it very difficult for BOM and PDF drawings when you send parts to sponsor machine shops. Names like 2014-110-001_Rev1.sldprt or 2014-110_Rev8.sldasm are much better and better prepare you for how companies in the real world work.

Don't be sloppy on your modeling. Constrain ever sketch entity - if you open a Solidworks sketch there must never be any blue lines.

Don't use project/convert geometry from an assembly into a part. It's great and fast when it works the first time but when you iterate and change designs it will be a minefield of broken references that will take for ever to fix.

We had this issue this year. Can you explain a bit more about how you organize the part numbers so that the team can handle them?

[Marc S.]

If you are starting fresh, I would recommend trying out Solidworks. I like it better than Inventor and, at least where I live, there's a lot more real world demand for it.

Look online for tutorials. Many FRC teams have put up FRC specific cad tutorials that are very helpful (973 RAMP being the first one to come to mind).

Another thing to keep in mind, is that a team sould never restrict students to just the "CAD team". Make sure that the people deciding how "it" fits together have experience putting "it" together. The best practice you can get is sitting down with your machinists/builders (they don't necessarily have to be the ones cadding but it will benefit you if they know how) and design and build a prototype robot in the off - season. Anyone can put up a CAD image on cd, it takes skill to design a robot effectively with your resources in mind. Doing it in the off season lets you learn from your mistakes with out hurting your team's productivity.

If you have any solidworks specific questions feel free to pm me, and of course others who post cad specific details on cheif.

[artdutra04]

Originally Posted by Dival

We had this issue this year. Can you explain a bit more about how you organize the part numbers so that the team can handle them?

I used a similar standard when I was on 228 as we currently use on 148: YEAR-SUB_SYSTEM-PART_ID. The top level assembly is 000, and each major subsystem gets a number like 100 for drive train, 200 for mechanism 1, 300 for mechanism 2, etc. Sub assemblies within that mechanism get numbers like 110 or 320. Each individual part is assigned a unique ID in the lowest assembly it is used in. If parts are COTS, you use the the manufacturer part number.

2014-000 Rev1 (main robot assembly)
- 2014-100 Rev1 (entire drivetrain assembly)
-- 2014-100-001 Rev1 (drive train part 1)
-- 2014-100-002 Rev1 (drive train part 2)
-- 2014-110 Rev1 (gearbox)
--- 2014-110-001 (gearbox part 1)
--- McMaster 91251A342 (#10-32 x 0.5in SHCS)
- 2014-200 Rev1 (mechanism 1 assembly)
-- 2014-200-001 Rev1 (mechanism 1 part 1)
etc

This is also really useful because in Solidworks you can set who has write access and who has read-only access, so you can have multiple people working on the CAD at once (one person could be editing -100 assembly and sub parts, another editing -200 assembly and sub parts, etc). The key to making all of that work is by opening all referenced parts as read only. To do that, check this box:

[Jay O'Donnell]

Take the summer to CAD something like last years robot or a battery cart or something like that, it really helped me to prepare for Build Season this year. You also don't necessarily want too much of a good thing, I've found that more than a few people working on one CAD can get to be tricky if you're not all on the exact same page. Also please save to multiple places, you don't want to lose all that work. Good luck with CAD!

[alexander.h]

Is there any link whatsoever between the programming language we use on our robot and the CAD software we might use to model it?

[Joe195]

Originally Posted by alexander.h

Is there any link whatsoever between the programming language we use on our robot and the CAD software we might use to model it?

Not at all. They are separate programs and there is no connection. The type of software your team uses really depends on prior experience.

[jamierose]

Along with what everyone else said, I suggest taking a look at this Design and CAD guide made by another student on 610. This was written by someone who had no idea how to CAD at the beginning of Grade 9, so it might be quite accessible to newer users.

http://www.chiefdelphi.com/forums/sh...d.php?t=125208

Designing mechanisms for robots is part of the curriculum of every Grade 9 in the school, so virtually everyone on the team knows how to design a part in SolidWorks and then make it in real life. Due to this, I can confidently say that almost every single student on the team now is better at designing in SolidWorks than our head of Manufacturing/Mechanical than when I was in Grade 9 and it was separate from the CAD division.

Basically, I suggest that the people who build the robot and the people who design it using CAD software learn the other skill eventually, as it makes everything so much easier.


We also have more basic CAD tutorials for the Grade 9 technology course at my school. I'll see if we can post them online.