How do teams that do little or no CAD work?

The trend is more teams using more CAD, over time, but I’m curious… How do teams that do little or no CAD operate … in particular, design? Hand sketches and/or drafting on paper? Of course, some gear/motor/actuator math still must be done using JVN calc or similar.

Are there teams that decide to do less CAD some years because they have fewer students with CAD skills / interest? In that case, what is the minimum CAD (e.g. 2D geometry?) you do?

Thanks

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White boards…and sketchy designs at best. We’re moving to CAD this year, and it should help improve us a lot.

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My experience has been that there’s a very small number of teams that effectively design, but also don’t use any CAD.

Frankly, the only one I can recall ever talking to was 1503, who told me in 2013 that they didn’t do any CAD design for their robot.

The vast majority of teams fall into “no real design work” or “does some level of CAD.”

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I think we fall pretty much in the middle. We benefit from the broad strokes of CAD, but don’t iterate much in it. We also have an inventory that doesn’t always match with the CAD, so you are kind of mismatching with what is on hand vs. what is quick to add to the model.

I think sketching is important, then moving to a full scale representation. Sometime that is CAD (cardboard-aided design). You spend more time iterating in metal, which is a downside. Those 20 iterations you did in CAD you might end up with 3-4 iterations in you can do by making parts.

I think the calculations remain similar for the most part. You also are building in larger margins for the most part, so I think you would have heavier parts for the most part than those CADed. Also considering that for thinks like CNC router, 3d printer, etc., that the parts pretty much needs to be designed and so teams doing little computer design work probably don’t have as much tools to work with.

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Kind of makes one wonder how anything ever got designed and built before we invented high end computer systems. Heck, they didn’t even have CAD to invent those high end computer systems!

But seriously…paper and pencil work great for sketching design ideas, and then making more formal scale drawings of those ideas. It even works for motor/gear calculations. You’d be amazed what people are capable of doing, without the help of computers.

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The small team I was with had CAD-capable students for three years. For the others, we had mentors who could help design some components with CAD.

For everything else, we used PAD (Paper Aided Design), the other CAD (Cardboard Aided Design - for templates), and LAD (Lumber Aided Design - 2x4’s and plywood - for prototyping and proof of concept).

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My years on 3946, very little of the design work was done in true CAD. A lot of parts were laid out in hand drawings, or in power point or other general drawing tools (even a few were laid out in Excel.) Other than the second and third year, the chassis was always based on the KoP (though often heavily modified). Things got a lot better in terms of superstructure and manipulators after we started using VersaFrame. Even where VF (or similar) couldn’t make what we wanted, we still used plenty of COTS structure, or we match cut or drilled from a COTS part to achieve consistency. Using 0.1" perf board (breadboard material, but without any conducting traces) also helped.

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Im really curious, how does one do design in excel?

Stolen from a YT vid:

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dilbert-saturday-640

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For many years we used PowerPoint for everything and really only CADed machined parts or after the robot was done.

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Like this, for example:

I’ve also used excel and its graphing capability to design non-parallelogram four-bar catapults (never built), to keep track of coordinates in selecting spacers, and to calculate spacings and angles for various other pieces/parts.

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here is an example of designing part of a robot using paper and pencil…it’s part of an underwater robot, not an FRC robot…I’m too lazy to look for some of those drawings, but I do have several around here somewhere.

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Drafting, as the mentor that did the drawings learned that throughout college.
Here’s a drawing:

Looking at the 2020 season, we arent 100% with who our 2nd mentor will be, as he is retired. He may or may not be able to stay for this season before moving on. His biggest role throughout build season was drawing the plans out for us to build.

Edit: could teams PM me with their average treasury? I believe we are ok with what we have but I’m just checking.

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I’m pretty sure our cnc guy ends up CADing the parts we CNC, but other than that we used white boards and a lot of asking our Chief Technical Officer

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CAD is a… interesting skill on the team. We never really had “CAD” as a subteam. Yeah we CAD-ed our robot but very simplistically. We don’t CNC either.

We do everything in sketches on the board and prototypes. We run through ideas for a week, vote, sketch, prototype, and build. We take into account the past accomplishments of the team, possible new things to learn, etc. while we create the robot. This year we built our first elevator, so we thats what we learned, but we used old concepts such as the frame being similar to our POWERUP! robot.

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Whenever I see a thread like this where people wonder how something can possibly be done without the aid of computers I have to laugh and marvel at the engineering that was done before computers even existed. Take a good look at a R4360 Wasp Major 28 cylinder radial engine sometime and remind yourself that something that marvelous was engineered without the aid of CAD computers and built without CNC anything under immense time pressure in the middle of a world war. While CAD and CNC and everything else modern computers can do for us make our lives (arguably) better and easier, I’m pretty sure any good engineer or future engineering mind can cobble together perfectly acceptable working solutions to just about any problem an FRC team will face with pencil and paper and some good old math.

Our shop is littered with pads of paper with sketches and dimensions and back of the envelope calculations.

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During the week separating our 2 competitions, i came up with a completely new hatch mechanism that actually held our hatch from Hab2. I knew it was to be pneumatically powered. I didnt know the math behind it. The pencil, paper, math was done by my mentor. I just built a prototype good enough to convince him.
“Put out the legos, build anything you want”

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Drafting by hand is basically the same thing as creating a sketch in CAD, it just takes a little bit longer to make precisely and it’s difficult to make adjustments without creating a new drawing. CAD is faster, especially if you are doing design iterations, but it serves the same function.

For 1726’s rookie year, all of the parts were designed on graph paper. I remember because I drew most of them! I still use the graph paper approach when sketching quick design concepts; it is a bit quicker than loading up software and it’s easier to keep track of the physical copy and stick it to a fridge.

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Before CAD, there was drafting. I still have an almost complete drafting kit from my “younger years”. Up until the 1990s, complete aircraft were designed on drafting boards with pencils and slide rules on mica sheets.
CAD software and computers were extremely expensive.
It is still possible for anyone with a minimum amount of drafting skill to come up with some excellent robot and part designs.

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