How do you know when to CAD vs draw up on paper quickly

[AdamHeard]

Originally Posted by Paul Copioli

Team 217 does exactly what Arthur explains happens on 228. We do everything in CAD and simultaneuosly do prototypes for critical items. If the prototypes find a particular geometry that work, then we will immediately CAD it in SolidWorks to get the manufacturing dimensions. See the attached pdf for an example of one of our assembly drawings.

$@#$@#$@#$@# Paul, Being a student on your team working on design like that must be an amazing experience....

I'm trying to work towards that with my students, but I'm probably decades away

[JVN]

Originally Posted by Paul Copioli

Team 217 does exactly what Arthur explains happens on 228. We do everything in CAD and simultaneuosly do prototypes for critical items. If the prototypes find a particular geometry that work, then we will immediately CAD it in SolidWorks to get the manufacturing dimensions. See the attached pdf for an example of one of our assembly drawings.

This process is especially AWESOME when you work with a manufacturing facility that works directly off the 3D solid models. We are lucky to have a sheet-metal shop that takes our part files designed in Solidworks, auto flattens them and sends them directly to the laser cutter / turret punch for creation.

I typically send CAD files to the shop late at night, and have parts ready by the end of the next business day. When you combine this quick turn manufacturing with a robot that is well designed and "drops together" it makes for some incredible meetings. It is easy to feel like our team is behind until one day *poof* the robot appears. This quick stuff also helps us do more iterations on our designs as we work to tune in the robot. Design is after all, an iterative process.

To answer the question of the thread, we CAD EVERYTHING.

-John

[Collin Fultz]

On 234, our manufacture and our CAD proceed in parallel paths. If there are complex mechanisms which require CAD before manufacture, we will do that, but again, only if required. This year, we have made an effort to keep the robot simple, yet elegant. Doing this has made it possible for us to build two robots for the first time. Admittedly, R2 has much fewer holes than R1

My advice...do what works for you. If you don't have the people/resources to CAD everything, you don't have to. The great thing about FIRST is that every team has such a unique identity...and they all work. Only in FIRST could so many answers to the same question be right answers.

[MrForbes]

Originally Posted by CraigHickman

Here's a good way to think about it: Would you trust yourself riding in a car you didn't do CAD for, and only sketched it roughly out?

Hmmmm.....would that include my 55 Chevy? my son's 59 Chevy truck? My other son's 70 Camaro? My wife's 70 Dodge? I didn't design these, I did modify some of them. I know they weren't designed with modern technology, but short answer...yes, I would.

This year we have some students on the team who are enrolled in the new pre-engineering program at our local community college. This is a joint high school/college program. There hasn't been any integration of the classes with the robotics team, unfortunately...they seem to be in different worlds.

But one day, it might all come together, and we'll have a lot of students with CAD knowledge, and computer resources for them to use (all of the Inventor work we've done so far this year has been on a few older student owned laptops). We have no sponsors in the manufacturing business, and no CNC equipment, so the move to computer aided manufacturing is either in the future or just a pipe dream.

Even so, we did use Inventor quite a bit this year for our robot design, and revising the design. We did not do much in the way of using it for making design drawings, it ended up being easier to just make a dimensioned sketch on paper to make parts from.

I'm very impressed with how 217 and 148 and others have managed to get their design process so well organized. It's something we should all aspire to, as it reflects how things are done "right". I agree with Adam that it must be an amazing experience for the students!

[Team 1782]

Sketching is by far the best way to get something made on Autodesk, they're not seperate things, unless you're like a Autodesk Prodigy, I would sketch first.

[Madison]

I design as much as I reasonably can in the time I have available. Usually, I'm able to take care of fit and function for major assemblies and parts and create accurate drawings for parts that require milling or laser cutting. Beyond that, though, we still use paper drawings to quickly communicate requirements and intent. In a lot of cases, I make paper drawings of parts I've modeled since it goes faster, but sometimes we'll develop parts on the fly and I add them to the CAD model later.

If we had a more efficient manufacturing process in place, we'd assuredly rely more on CAD models than we do even now. But, because most of our machine is made from laser cut parts, or with a drill press and saw, I can get away with being lazy.

In fact, so far this year, we've not used our milling machine for anything at all.

[JesseK]

Our design process is whiteboard --> sketch on paper --> CAD spacial representations to get critical dimensions/relations --> Prototype --> Prototype even more --> CAD critical subsystems --> Build, test & integrate. It's amazing we even have that since every one of our mentors, myself included, do software in our careers .

We're still learning, and we get hung up on not using solutions that we can't fully envision working for us...even when we're staring at a video of it on Youtube (prime examples this year are our conveyor belt & shooter). We also hate settling for less because we're unwilling to put the effort into venturing into the unknown...that is, it's unknown for us. So really it boils down to the fact that if we don't know something will work or exactly how it will work, it's impossible for us to CAD something with any detail before we prototype it...but we will prototype it to near perfection! We really spend most of our time in the shop improving our prototypes before we do a final CAD on them. Drawings are sometimes made while in the shop, then added to whatever CAD models we have later. It's not really healthy for students to use a computer when they have aluminum shavings all over their clothes anyways .

Hopefully our "poof, here's your robot" day will be tomorrow since we took so much extra time to prototype & design . Cheers!