Better Modeling using Pencil and Paper

I am finding more and more posts on engineering related forums as well as discussions with industry professionals that cannot believe that designers and engineers have little to no idea how to sketch using a pencil and paper.

Personally, sketching helps me reduce my modeling time anywhere from 20-50% while at the same time increasing the simplicity and accuracy of my model.  In my Advanced Modeling course at NTI I start off the course by asking the students to define advanced modeling.  Those who do not know me yet will answer with functions like Surfacing, Sweeps, Lofts, Sheet Metal, Weldment so on and so forth.

Then I pull out my soap box and tell the students that these are actually industry specific standard tools.  If you are working on sheet metal day in and day out then those are generally the core set of tools you use son on and so forth.  Same goes for Mold Tools.

The next part of my presentation talks about advanced modeling being about modeling using the most basic tools possible to accomplish a manufacturable component, assembly that 2 years down the road the next newbie can immediately open and make the necessary changes for the next design.  I talk about taking the time to model as best you can in a manner that will allow you to import you model dimensions to the drawing to save time in the detailing process.  Model so that your drafts, fillets, chamfers (dare I say it “extruded text”) are at the bottom of the feature manager tree so they can be easily suppressed.  Use the hole wizard to aid not only in assembly but also use you companies standard hole callout format.  Try to limit the parent child nightmare by relating back to datum planes, origin or you base feature.  These are tangible items in which i can immediately show the results and demonstrate the value.

Being able to sketch your part before modeling is proving to be more of a challenge.  I cannot tell you how much time I have saved throughout my career by sketching before I model.  It is a great way to spend those countless hours in drawn out design reviews (cat fights).

What value do I find in Sketching?  It allows me to envision how my model will be constructed (is this a cast to machined part? will this become a progressive die stamped part? how can I ensure my design intend in understandable?), add notes to features that may associate to other parts of the assembly (this hole is related to part B, the connection is a shaft the will be pressed into 2 bearing what was that fit again?  Oh yeah it is right here in my sketch), list our drafts, minimum radii, wall thickness, materials to select from, I can add all kinds of research to a sketch that will reduce my time at the computer and increase my productivity while I am at it.

This is proving to be a challenge to convey to students.  They want to work on the computer all the time.  I even talk about my time in Florida (the highest number of lightning strikes per inch capital of the world) and how there is often times you can not have a computer with you.  Or how about when one of your machines is on the brink of failure but we can only take it offline for a given amount of time to reverse engineering the no longer existing replacement parts needed to over haul the machine.

Anyone else in the Legion have some examples of how they use sketching to improve modeling productivity?  Any one out there think that sketching is the dumbest thing next to the pet rock.  Let me know.  My student will benefit from all views.

Author: fcsuper

As a drafter, mechanical designer and CAD engineer, I've been in the mechanical design field since 1991. For the first 8 years of my career, I was an AutoCAD professional. I utilized AutoLISP and many other AutoCAD customization features to streamline drafting activities for 6+ drafters and designers. I authored several custom functions, one of which was published in the March 1997 issue of Cadalyst Magazine. Since 1998, I've been used SolidWorks non-stop. I've worked to utilize the SolidWorks' user environment to simplify drafting and design activities for 20+ engineers. I've created this website to provide current information about SolidWorks from a variety of contributors. More recently, I am now employed by Dassault Systemes as SOLIDWORKS Sr. Product Definition Manager to improve drawing, annotation and MBD related areas.

16 thoughts on “Better Modeling using Pencil and Paper”

  1. As someone who started drafting on actual drafting boards, I totally agree. I feel it should be part of the actual coursework to draft using pencils and triangles and drafting machines. I haven’t touched a drafting board in over 12 years, but I still have all of my tools.

    People who have always used a computer without the background of a drafting board, do not fully comprehend what it took to create a drawing. Having the board background just translates into being able to sketch a design.

  2. With rare exception, a sketch is the only way one is going to come out of a brainstorming session with a plan to follow. As much as CAD’ing has improved, it’s still not easy to concept something from scratch with a whole committee breathing down your back in realtime. Sketches are the way thoughts are shared within the group in a live setting. Then those sketches are turned into models (assuming more sketching isn’t required on your own).

    For me, I work from principle engineers’ sketches from time to time. I do much of my own work in 3D because I imagine the stuff in my head and then apply it in the model. Maybe this is a bad habit of mine. 🙂

  3. I agree with Kirk Jess, everyone should have to go through the old drafting board process before moving on to CAD. This helps establish the mind set on how you sketch things before you actually put the pencil to paper. I have not used a board for over 17 years now and I still scribble down rough sketches of how I plan on starting a part or assembly or modifying a existing part.

  4. Hey guys, this is so important!

    Drafting experience, even rough sketches, help you recognize relationships between parts. Not only that, but laying something out ‘permanently’ on a sheet of vellum makes you consider the space and views you decide to use.

    If you can take a drafting course take it.

    one other interesting note. why do we make notes when we sketch things out?… then leave those off of drawings? sketching can help you see what type of instruction you need to give either with notes, or with better views.

    Thanks for bringing this up Chris!

  5. Thank you all for repling. I thought this might be a hot topic. How would you all go about stressing this skill to new employees, students, people who are interested in the Engineering or Product Design.
    I prefer to consider all of these fields as Problem Solving. This has a nice ring to it and with as many people as there are in the world we will never run out of work as problem solvers.

  6. I agree that visualization sometimes needs to happen in 2D for a bunch of reasons. This is part of my “design happens in your head” argument. Pencil is the most direct and controllable way to get something out of your head to communicate to others. It’s still a great tool, even after hundreds of years.

    I also agree that the computer is not the answer to every problem. I think a prerequisite for machine design should be a lot of time wrenching on real (physical) machines.

  7. I whole heartedly agree with Matt. My father worked construction his entire life and he always commented that architects should be required to put on a tool belt and work in the field to actually learn how material is converted into an end product. Engineers and architects have the college degrees, but the guys with the high school education are the ones who need the build it.
    Being able to buld your design with your own hands makes the difference on your future designs.

  8. Chris,

    One way to drive home the concept of sketching being a good way to start is to have the students go through a brainstorming session on a design. It would be just like real world. Maybe split the class into 2 teams have one work with sketches and the other creating models, give a time limt of say 1/2 hour and have them submit 3 variations. Of course this is loading it in favor of sketching but it might get the point across.

    Here at Sun Nuclear even our physicist can sketch. It is most often done on a white board. I know several of them have manual drafting classes in their background So I would have to agree that drawing board class would be good for all.

  9. Sketching with a pencil is a must. I’m no designer. But it is the ONLY real way to quickly and smartly convey and idea from ones mind to another with *NO* confusion what-so-ever. As many have said, it also gives you a starting point. You don’t just pick up a mouse and start “modeling”. Even in my simple world of sheet/plate/mechanical, sketching is of paramount importance. It is not uncommon to get strange looks or hesitant voices from people in the fabrication industry that feel as though they will be frowned upon if they pick up a pencil/biro/whiteboard marker and go rank on a lil’ old piece of A4 paper all because they see impressive 3D models on a computer screen and think its somehow a bad thing to scrible!

    Sketchying is the lines and arc’s of this whole design/CAD/technical world.

  10. I too teach, AutoCad and SW, and . . . . mechanical drafting. I find myself loosing alot of class time on those who have not bee through the pen and paper experience. Sad part is, like so many schools, mine is about to drop the mechanical drafting req., Mean time I’m lobbying for a hybrid course, with the thought that the CAD course work can be stepped up in complexity. Little hope for this.

  11. Jkerr,

    I saw your comment about your school dropping the the mechanical drafting requirement. This is truely a sad event. Sorry to here about that.
    In my class I enforce that until I see the orthographic sketch with dimensions and GD&T placed in the sketch they cannot login to the software.
    The students may not appreciate it now, but they will later.

    Good luck on the hybrid course.

    Chris

  12. Drawings themselves may be waning in importance (though this is arguably not the case yet), but the information we put on drawings is not becoming less important. It still needs to be stated outright. Just because there is a reliance on the model, that doesn’t mean the all the specifications previous placed on the drawing are no longer necessary. Drafters are still needed, whether drawings are made or not, to ensure proper documentation that can be employed as part of legal contracts between customer and vendor.

  13. I agree to a certain extent that to have a capability is important but being able to scribble on a scrap of paper is not the important capability. What is ESSENTIAL is being able to work through ideas quickly, mentally, and fully before work is wasted on something that won’t work. I have often seen in meetings that flat cross sections are used to come to an ill conceived design because out of plane features do not permit the 3d allocation of space. This happens often in flight weight hardware design because space and weight is at a premium.

    There is a reason that Solidworks and other 3d modelers won out over AutoCAD. It is for the very reason that 3D is far more effective at catching problems and fundamentally communicating reality. Drawings do have to communicate tolerances, at present, but models are far better at communicating accurate shape than any flat interpretive 3D puzzle that drawings are today. Avoiding this knowledge will only be at the cost of American industry slipping further behind. Clinging to the old will only quicken your demise. Accepting the new on basis of the fact that it is “new” will only quicken it as well. Full knowledge of both systems and why they are needed and where the world is going and has been as well as your place in it will be the best route. Adopt the new carefully. Do not fight it.

    That said drawing with pencil is important and its importance is less every day. Deal with it.

  14. Hey Casey Gorman,
    I have not heard your name in quite some time, How is the Florida user group going?
    I really appreciate you idea of the brainstorming. What I am currently doing is almost on that line. When we work on a project where we start out with the Brainstorming session to sketch out the assembly concept. From this concept we discuss the function of the end product and then branch out into how each of the primary components are to function within that assembly. The students add leadered notes to those items or areas and identify tasks that will be required of them when they do model. Then, each week the students are devided into 2 groups. Each group researches a provided material and manufacturing process that can be used for that part. They use their reasearch to debate with the other team about why there selections are better that the other. While they are doing their reasearch they are sketching out the components, placing dimensions (or dim place holders that will require more information) to ensure all the FOS are dimensioned and toleranced, all the FOS are located with appropriate tol’s and their dimensioning is following the guidelines spec’d out for that process. One additional item I have them attempt is to make a list as to what they think their feature manager will look like as a road map for them when they model the part.
    Students who want to learn, really are taking to this approach and prospective employers are very interested to see a living project portfolio when they interview our students. I just need to work on making sure the students who are not grasping the ideas from the start are able to understand a little faster. Tough position.

    Thanks Casey,
    Chris MacCormack (Happy from 3rd Degree Engineering)

  15. Paul,

    This article must have hit a serious nerve with you. This article was never meant to replace modeling with sketching, but for the up and coming designers to embrace the tool of sketching to make better models. I will say that I have run into a company that is using stylus pens and monitors to do their design, which would neccesitate the ability to be able to sketch and visualize in 2D. And they do this with SolidWorks.

    After working in Florida, where power was out about 25% of the time, I do not think I will ever say that paper, pencil and 2D drawings will be obsolete. At least with these items I do not require technical support or power to concept an idea that can be quickly prototypes by a manufacturer.

    Some of my best brainstorming and concepting has happened at events where a computer is just not a feasible accessory. (Not a big fan of those who occupy my bar tables with wires and computers.) I am a big fan of having heated discussions with groups of people from different professional areas to help solve important problems. For this type of concepting I have found coctail napkins or receipts and the servers pen to be excellent tools to get points and ideas across that will lead to even better modeling when I return to a computer station to iterate.

    Although many of my students employers say they need someone with mad CAD skills, if the person cannot visualize 2D, or quickly communicate their ideas with sketches, they are just a CAD jockey. Some one who takes anothers napkin sketches and concepts and generates a CAD model. Not a lot of room for advancement for CAD jockey so to speak.

    3D modelers are a great tool, but that is it. There are still far more companies using 2D Cad software for manufacturing design than 3D Modelers and most companies with 3D modeling software still use 2D CAD software as well. Although companies still are making the change, 2D will be around for a long, long time.

    Best of luck
    Chris MacCormack

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