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

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?

There's a fun exercise you can do to test this out. Have one of your team members go grab a random part from an old robot, mainly one that was Milled simply. Have him/her sketch it out "quickly" on a piece of paper, with all the dimensions THEY think you'd need to make it. Give that drawing to a team member who has not seen what part it's drawn from, and have them try to make it. Unless your student has taken some drafting courses, or is quite gifted in conveying all the details of the part on a sheet of paper, I'm pretty sure there will be errors.

If you sketch it out as you go, you'll always be building under the pressure of the clock. If you CAD it entirely, all you have to do is put the model together. Motion can be tested, speeds can be calculated, and interference can be looked for before hand. You'll end up with a more honed and precise machine, which should elevate your level of competitiveness.

[CamFam1]

Thanks for all your guidance everyone. Please consider another dimension to the question.

If you are running short on time, when would you come to a point where you would say do it in paper and pencil and forego putting pressure on CAD so you can have a robot rather than possibly risking not having a robot?

I see how it's ideal to CAD. When do you let it go and try using paper and pencil? Have you had any experiences like this? How did it go?

[Akash Rastogi]

Originally Posted by CamFam1

Thanks for all your guidance everyone. Please consider another dimension to the question.

If you are running short on time, when would you come to a point where you would say do it in paper and pencil and forego putting pressure on CAD so you can have a robot rather than possibly risking not having a robot?

I see how it's ideal to CAD. When do you let it go and try using paper and pencil? Have you had any experiences like this? How did it go?

If you think about it, having full CAD of all the components can save the time you are losing by perhaps figuring out dimensions on paper. The fabrication process goes a lot faster, which is what Adam basically said.

We learn how to create properly dimensioned tool assisted drawings too though.

Graph paper is the shizzz.

[CamFam1]

Maybe I'm asking a different question than I should be asking.

How about this question. In which week do you like to have your CAD work completed by? What should you do if it is taking longer than you had expected?

[artdutra04]

It was only two days ago in which I finished up the CAD of the elevator and shooter on 228's robot. However, the chassis and ball intake were completed over two weeks ago. The date in which the CAD has to be done is entirely dependent on how fast you can fabricate parts and how many revisions you want to go through before you shoot the designers and build it.

Because I was slow on the last bit of the CAD, now I get to spend all my free time running parts on the CNC mill.

[Molten]

AutoCAD, the speed of hand and the accuracy of computer. This makes it where I start. When I don't have it, I'll resort to hand/Inventor. But my start is always AutoCAD.

[s_forbes]

Originally Posted by CraigHickman

There's a fun exercise you can do to test this out. Have one of your team members go grab a random part from an old robot, mainly one that was Milled simply. Have him/her sketch it out "quickly" on a piece of paper, with all the dimensions THEY think you'd need to make it. Give that drawing to a team member who has not seen what part it's drawn from, and have them try to make it. Unless your student has taken some drafting courses, or is quite gifted in conveying all the details of the part on a sheet of paper, I'm pretty sure there will be errors.

What we do instead is try to make all of the students understand the importance of being able to draw things correctly with proper dimensions. "Did you draw a picture of it?" has kind of become a catch phrase on our team.

As far as our robot design goes, we don't use CAD software as often as we could. If something can be drawn to scale on paper, then we just do that. There are always a few things that are easier to do in CAD though, like our helix this year. It's nice to know that it will actually fit on the robot before we put it there.

[R.C.]

In terms of how to model up designs. The best way to visualize them 3d is too use a simple modeling program such as 3ds Max (Sorry not tooo simple) or Google Sketch Up (I am learning it). We used it for our bot and we got 4-5 concepts drawn up in about a day which made the Cadding easy. And I use paper to start because it makes it easier to CAD.

[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.

[Paul11]

Our entire robot was CADed before we cut metal. Hand drawings are good for early design or if a team member must convey an idea or a part placement to the designated CADer.

[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!

[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