Proper Drafting Technique

[Akash Rastogi]

Hey CD,

Our team teaches traditional drafting (using good ol' hands) along with CAD. I wanted to know what other teams teach this to their students and also to get suggestions for books/resources we could use for further teaching. This could also include available drawing kits/stencils/tools in stores. I find that it is a lot of fun being able to hand draw designs and mechanisms so I try to break out the graphing notebook whenever possible. Any help is appreciated.

I hope there's engineers or draftsmen on here that still do a lot of full hand drawings. I saw some on 234's site and I found it so cool for some reason. haha

Regarding the time of this post- I'm all hopped up on Red Bull and soda right now ..yea I love studying for physics that much -_-

[Cory]

We taught very basic hand drafting skills just as a prelude to CAD. The hope was that doing it by hand would help the students to understand 3 view orthographic projections, how to represent features with hidden lines, etc.

All our actual design work is done in Solidworks.

You should check out 111's website. They have quite a few ridiculously detailed/complex hand drawn prints.

[Molten]

One of the coaches on 1766 was a draftsmen in the industry for many years. He likes to make sure that the people on the drafting team know how to manually draft even if it isn't always used extensively.

My suggestion: To make each student manually draft a screw in detail. It really helps them respect the art. You can't really master something, if you don't have a healthy respect for it. I'm not really sure where he got the actual drafting tools though....sorry I can't be more help.

[sanddrag]

In middle school I took a real, old-fashioned drafting class, and it was fantastic! We had the proper drafting tables, boards, T-squares, pencils, erasers, scales, triangles and everything. We were taught proper block lettering, arrows, line weights, pencil holding, etc. Unfortunately, I don't think you'll find this too often in schools today.

On 696, I would typically do a pre-season "workshop" that would cover the same basic things Cory mentioned, along with some dimensioning and tolerancing.

For some books, Interpreting Engineering Drawings by Cecil H. Jensen is a good one, that has a lot of good workbook-style exercises inside.

Fundamentals of Graphics Communication by Gary R. Bertolini and Eric N. Wiebe is another one I have that Cal Poly has required, although I haven't read this one much.

Regarding the time of this post, I call it studying for college finals.

[Scott L.]

Originally Posted by sanddrag

In middle school I took a real, old-fashioned drafting class, and it was fantastic! We had the proper drafting tables, boards, T-squares, pencils, erasers, scales, triangles and everything. We were taught proper block lettering, arrows, line weights, pencil holding, etc. Unfortunately, I don't think you'll find this too often in schools today.

On 696, I would typically do a pre-season "workshop" that would cover the same basic things Cory mentioned, along with some dimensioning and tolerancing.

For some books, Interpreting Engineering Drawings by Cecil H. Jensen is a good one, that has a lot of good workbook-style exercises inside.

Fundamentals of Graphics Communication by Gary R. Bertolini and Eric N. Wiebe is another one I have that Cal Poly has required, although I haven't read this one much.

Regarding the time of this post, I call it studying for college finals.

I took Drafting in Middle school, and actually have all the drafting tools. The book we used in school and that I have is: "Exploring Drafting fundamentals of Technology" byJohn R. Walker. Published in 1987
I also Have the book: "drafting fundamentals 1" by Street, Cleland, Earle

[MrForbes]

I have enough of a challenge getting students to make sketches....hmmmm....

[terryo]

Originally Posted by squirrel

I have enough of a challenge getting students to make sketches....hmmmm....

Squirrel, I have the same challenge. This year we're trying a new approach:
Plan before you build (go figure?)
We, the mentors, have mandated that no one picks up a tool until the concept is approved and the sketches are done.
We'll see.....

[Ryan Dognaux]

Originally Posted by sanddrag

Fundamentals of Graphics Communication by Gary R. Bertolini

As someone who has met Dr. Bertolini, I have to also recommend this book. We used it extensively as a baseline in some of our early classes and it really covers a wealth of knowledge for drafting, CAD, visualization, etc. The older editions are pretty much the same as the new editions so you could get them for pretty cheap too.

[,4lex S.]

As useful as proper technical drawing skills are usefull, I think AutoCAD is a better place for this kind of drawing to be made. It is considerably faster, and produces something that can be easily moved around and manipulated. As cool as they look, I don't think they are worth the time nowadays.

I think if I was going to do any initial graphics instruction or work with an FRC team, I would try to teach freehand sketching. When it comes to graphics communication, the most important thing is usually the freehand; its fast, easy, and transmits more information per unit time used than other methods. As long as you teach it from a technical perspective (cutting planes, proper views, proper solid creation...) it gives a strong basis for 3D CAD instruction as well. A good 40% of my first year university graphics course was pure freehand, in order to lay the foundation for AutoCAD and Unigraphics.

[scottydoh]

Originally Posted by ,4lex S.

As useful as proper technical drawing skills are usefull, I think AutoCAD is a better place for this kind of drawing to be made. It is considerably faster, and produces something that can be easily moved around and manipulated. As cool as they look, I don't think they are worth the time nowadays.

I think if I was going to do any initial graphics instruction or work with an FRC team, I would try to teach freehand sketching. When it comes to graphics communication, the most important thing is usually the freehand; its fast, easy, and transmits more information per unit time used than other methods. As long as you teach it from a technical perspective (cutting planes, proper views, proper solid creation...) it gives a strong basis for 3D CAD instruction as well. A good 40% of my first year university graphics course was pure freehand, in order to lay the foundation for AutoCAD and Unigraphics.

I agree that as far as technical drawings, CAD is far superior, and I agree that in the FIRST setting, CAD should be taught more than hand drafting.

Not to discredit CAD renderings which in themselves are stunning...
But, I would like to argue the point that aside from looking "cool", I feel that drawing every single line and detail by hand allows you to better understand your design, and drawing techniques. And it definitely helps your understanding of the CAD thought process.

Before I started college, I had the same point of view, that CAD was completley superior to hand drafting, and that I would never use hand drafting, but the more I was forced to use it, the more I began to like it. Right now, as far as visual quality, I think hand drafted drawings look much better nicer than CAD drawings. All of the "mess ups" and smudges give the drawings character. And personally, even though I have 4+ years of Inventor and AutoCAD experience through FIRST, I think that hand drafting is 10x easier than drawing on the computer. Everyone who's used any kind of CAD software should know what im talking about here...when your drawing on the computer, especially 3d modeling, crazy stuff can just happen out of know where...

Oh, and your t-square and pencil can't crash, unlike your laptop

[Ryan Dognaux]

Originally Posted by scottydoh

Everyone who's used any kind of CAD software should know what im talking about here...when your drawing on the computer, especially 3d modeling, crazy stuff can just happen out of know where...

I'd disagree with this. Maybe at first the crazy stuff happens, especially when you're getting to know the in's and out's of a software package. However, the great thing about CAD packages these days is being able to derive your drawings from your parametric model and have those drawings update whenever a model is changed. If you were hand drawing this and the design changed , there would be a significant amount of time editing or creating a new drawing.

I agree that drafting by hand absolutely helps to understand proper drafting techniques and standards. That being said, it's almost 2010 - time to go digital people.

[scottydoh]

Originally Posted by Ryan Dognaux

I'd disagree with this. Maybe at first the crazy stuff happens, especially when you're getting to know the in's and out's of a software package. However, the great thing about CAD packages these days is being able to derive your drawings from your parametric model and have those drawings update whenever a model is changed. If you were hand drawing this and the design changed , there would be a significant amount of time editing or creating a new drawing.

I agree that drafting by hand absolutely helps to understand proper drafting techniques and standards. That being said, it's almost 2010 - time to go digital people.

Experience doesn't really have much to do with "crazy" stuff happening we have a mentor who has 7-8 yeard of experience with inventor and 10 or more years with autoCAD, and he still has unexplainable stuff happen. Its just a given when you have a computer program attempting to replicate your input.

But I do agree about the editing bit. I know what its like to be awake for 48 hours straight, up all night working on drawings, only to go to class and have the professor whip out his sharpie marker and completely change your drawing...Its a real downer. But as far as editing...I don't know how much hand drafting you've done, but its usually not that difficult or time consuming to fix with an eraser and eraser shield. I also think that the consequence of having to change the drawing forces you to pay more attention to your design decisions while your drafting, I know it has for me. Thus making you an all around better draftsman. Hey, we got by for literally thousands or yeard with simple hand drafting just fine. It can't be that bad.

[Molten]

I'm far better at AutoCAD because I know the methods used by manual drafting. I know different techniques and can draw most any geometry without using advanced commands. If you can draft by hand with just circles and lines, then you can do the same on AutoCAD. The problem is that it is a lost art. I'm not saying every draftsmen should need to sit down and manually draft everything. However, I will say that they should have the ability and understanding to.

Also, a note on "crazy" stuff: Inventor sometimes does weird things when you don't use parametric(I often don't, so I can relate). However, I have never had this problem with AutoCAD. It does exactly what its told every time. You just have to be careful how your telling it what to do. If you don't tell it right, it might interpret a different command. In this case, the blame goes to the ambiguous input and not the computer's fault.

[Big Ideas]

For me. CAD can be great for drafting. But there are times when you want to get a spacer made and a hand drawing only takes a minute if you know how to do it.

More important for me is that CAD tends to NARROW and FOCUS my thinking. This is good for detail design and drafting but death to brainstorming and broad concept exploration. Being able to sketch, render, and draft in multiple views by hand, is IMPERATIVE to getting concepts recorded, and shared with out the burden of knowing the little details of a concept. Even better is being comfortable combining BOTH skills. CAD drawings of known items (C-rio, wheels, motors, . . .) give you scale and hand sketching fills in the blanks. This is the "Paper Dolls" part of design, also know as "System Drafting".

In any case, a drawing is important. You should never machine anything without having a drawing of some type to work from.

[EricH]

I once did 2 or 3 sketches inside an hour, by hand (pencil, paper, ruler). I was able to turn 2D sketches into 3D interior/exterior view just by changing the line. 2 years later, one of the sketches is still floating around the team I did it for. Still no CAD for that one, that I know about...

Until CAD software can take a pen/pencil drawing and turn it into a 3D model instantly, both are very good topics to know.

Now, if I had to do those sketches using a T-square and other drafting tools, it would take considerably longer. It's also harder to modify them well.

CAD's strength is that you can change anything you need to and see how the parts fit together. Freehand sketches are fast, but usually not to scale. Drafting is to scale, but not fast.

These days, I'd start with perspective and freehand, then move to drafting or CAD.