Way of designing 8

[linqur]

Hi

How would you define you way of designing?
Do you model what you have ready in your mind?
Or you think in 3D? Meaning that you depend fully on modelling and visualizing and simulating possibilities of your CAD?


BR
Linqur

 

[swertel]

I think in 3D. I have since the days of manual drafting. I always have a 3D picture of my design in my head, including all moving parts. I can't put even the smallest component on paper until I have the overall design working in my head.

 

[MadMango]

I agree, you have to have the basics of the design in your head. This is based off personal experiences: you've seen something similar in the past. After you have that idea, you capture it on your monitor, be it a 2D layout sketch or a 3D simplfied model. For me, after it's captured, it's much easier to investigate variations of the original design.

After I have something working, I go back and start to detail that simplified model. A simple level arm will most likely not stay so simple, especially after you take into consideration manufacturing, reliability and assembly. "The attempt and not the deed confounds us."

 

[linqur]

I have to agree with you. So far I have put too much importance on modelling but seems that not everything is possible to assmble that has been modelled on screen

I have no background of 2D to teach "mind design".

Linqur

 

[drawoh]

linqur,

I do not see how mechanical design can be done competently by someone who does not have good spatial perception skills. In other words, they must be able to visualize their concept, and anything shown by a drawing, as a 3D object.

The 3D CAD is a tool that helps you will all of this.

JHG

 

[linqur]

There is still some hope as the person has come to understanding that something should be changed

 

[Hush]

Interesting topic.

I'll give you my belief (and thats all it is, no facts or medical data to back it up). Some people can roll their tongues and some can't, some people dream in colour others in black & white, some people can visualize an object in 3D and some can't.

Before solid modelling came along you didn't have a choice, if you couldn't visualize the part in 3D and be able to rotate it and explode it in your mind, you would have difficulty trying to create a machine drawing. I'm guessing that 20 years ago if you couldn't see in 3D you probably switched from design to sales or management or some other field.

Now, with 3D modelling, you aren't required to create the part in your mind, you create it on the screen. If you can't see in 3D are you less able as a designer? I don't know, like optech I've always been visualize in 3D so I really can't imagine being able to design a complex part without that ability.

 

[drawoh]

Hush,

If the designer's is spatially challenged, but their first idea is a good one, they will succeed with 3D design. The fun starts when the idea is not good, or the idea almost works but needs a little understanding.

Consider this. The only official way to communicate your design to a manufacturer is to create 2D drawings with dimensions and tolerances. If I don't understand the conversion between a 3D object and a 2D representation of it, I will not be able to commicate it to anyone else.

JHG

 

[sancat]

Hi,
I always try to design in my head in 3D, and hand draft it using lots of paper and isometries. We do use cad 2 or 3d but just for sending manufacturing details to the workshop or the client.
I think that it would be challenging for someone without a clear 3d imagination to design a complicated device. Having said that, there have been times that we felt we must build a cartonboard or even a steel model to understand a very complicated device. The most challenging part has been to comunicate efectively and fast enough the way that things work, since we use a collaborative design framework.
hth sancat

 

[MASSEY]

I design in my head all the time: front view, top, right side, iso, flip it over, sometimes get inside it and look out, and when I run into a problem - the solution comes usually when I least expect it - as when I am doing something other than thinking about my current project.

You get so full of what you are building and you know all the principal parts so well that solutions to problems reveal themselves when you are relaxed and not stressed about how to solve the problem.

The actual 2D or 3D drawing is tedious and comes only when the parts have been "roughed out" in my mind.

I also find that as larger projects are built in stages or phases, that it is helpful to hack out the drawing on the computer and look at the completed section of the project in 3D so my mind can relax the details up to that point. This allows me to concentrate on "new" phases in finer detail without having to "remember" the details of previously solved issues.

I sure ain't no Einstein - hell, I don't even know if I spelled his name right - but I read some of his published memoirs and I remember him stating that when he was contemplating light travel and time as compared to light and so on, that he would picture himself as riding on a beam of light traveling through space.

 

[tapetotape]

I'm still laughing at Massey's answer, funny guy. linqur's question is one that could keep designers and engineers talking all night.
Having spent a number of years as a journeyman toolmaker before I drew my first line on paper and therefore having learned to convert 2d dwgs into 3d reality I can say with confidence that 3d visualization is an excellent aid to design.
That being said however there are a number of other important criteria that are equally important to good design.
Such as:
1. End use. No matter how pretty, cheap or fast it gets built, it must work.
2. Fabrication. Know your fabricator and the tools and methods they use. Tailor your details to their methods to avoid operations that your fabricator doesn't normally perform.
3. Maintainability. Ensure that wearable parts and parts that need adjustment are readily accessible.
4. Locate, locate, locate. The purpose of putting it on paper is so that it can only be interpreted in the way it was intended.
5. Cad really IS just a tool, albeit a very good one. The cardinal rule still applies - garbage in, garbage out. I can't draw much faster with cad than a good manual drafter can on paper but I can erase a lot faster. I can try a lot more ideas faster on cad but a good manual drafter has learned to think.
I could write more but I'm starting to bore myself, the rest of you probably stopped reading awhile back.

 

[Biggadike]

Here's a thing...

I work in an office with nine designers in it. We design complex electromechanical equipment. What you notice is the way people work is very different depending on their abilities:

The technical director has been doing this stuff for aeons. He hardly needs to sketch a thing before the final design because he's got such a library of solutions and experience. He could design a tricky bit of kit with a few lines in 2D CAD and fill in the details as the final manufacturing drawings are created.

Some of the senior designers put a few key lines down and sit staring at them. Visualizing all the problems, assembly, functionality etc. Every now and then , they'll detail up a little section and move on. They've got the whole machine in their head but the lines they draw help them keep it accurate.

We also have a less experienced designer who diligently models everything in 3D CAD. He loves to get those little models just right. It always looks really pretty but close inspection often reveals a lack of understanding or attention to detail and his stuff hardly ever works first time.

 

[linqur]

Biggadike, do you have belief in this young designer that he will gain experience in (how many?) years?

Can you all bring back some memories from your starting stages as designers? How long did it take to start seeing mechanisms clearly in head?

BR
Linqur

 

[trihydrate]

Massey,

You have discovered a very key fact about the way our minds work. That is, your mind works best when not stressed.

I have read a book by an author named Alfonso Lopez, titled "Double Your Capacity In Two Hours". He can be reached at alfonsoafrica@yahoo.com. It is very interesting reading.

Lew

 

[Scoobystu]

I use 3D cad and have a method of working from the start and the end and arriving at a design somewhere in the middle. By this I mean I look at the idea and then think about whoever is making it, can it be made, how easy it is to put together and is it safe. As our workshop is right outside where I work I very often hear if an idea is hard to assemble.

Generally I talk to different people, the guys who are on assembly, sales and other colleagues and ask them what they think, sometimes the result means starting from scratch. This is sometimes necessary and with 3D cad very easy, as you can keep the bits that do work and modify or redesign the others quickly.

There is of course the old 'Keep It Simple' rule as the easier it is to make and put together the fewer problems you will have ..... allegedly.

 

[MadMango]

I think design is an innate ability, either you are born with it or not. I am not sure you can cultivate a “designer” from someone that doesn’t think spatially. I know folks that have been in engineering for 30 years, and degree or not, they aren’t designers. They might be able to develop a system that meets/exceeds all required specifications, but there’s no aesthetic quality to the end product. Also, there are drafters (CAD jockeys?) that are good at what they can do, but might not have the experience/knowledge to know what will work or what won’t. I think there will always be a separation between engineers, designers and drafters, but the lines are being blurred all the time by more capable software. "The attempt and not the deed confounds us."

 

[Biggadike]

Linqur,
The answer is pretty much as MadMango says. Some people are good designers, a few are great designers and some are just little more than ordinary bods who happen to know how to operate a CAD system and remember a few bits and bobs from university.
I see mechanical engineering (Design is a BIG field) as creative problem solving in 3D with applied physics / manufacturing / materials / ergonomic / service / safety considerations taken into account. If you can do it with flair, imagination and innovation you get my vote.
Some people are fairly low on the learning curve but they'll get there. Other people just don't get it.

 

[tomwalz]

If you are really bad at mechanical design, as I am, then you can get a large library (books, catalogs, on-line, etc.) and see what parts of the problem have already been solved. We designed and built our filter systems out of the Grainger catalog. (Not quite true but pretty close.) Personally I like to put a couple parts together, go stand in front of a customer and get their opinion. Repeat as often as necessary.

For some reason I seem to understand what atoms and molecules want to do or are willing to do in a chemical processes but mechanical stuff is pretty much like a monkey with a jig saw puzzle.

A couple points I live by. 1. Check with the customer and / or intended user early and often. Even if you know their suggestion is wrong. Cobble it together and show them. (Besides sometimes the people on the plant floor are smarter than engineers.) My way isn’t very flashy but the equipment works better than promised and that ain’t bad.

2. Do not have anything made until you exhaust all possible resources for purchasing a part. It is a lot of fun to sit down at a blank screen and design whatever you want. However it is generally much faster and less expensive to use existing parts.

Tom

P.S. get a copy of Five Hundred and Seven Mechanical Movements, Henry Brown, Astragal Press.

 

[Rampower]

Come on guys, prior to doing any modeling, it's obvios you have to have some solid model visualized in your mind! I totally disagree with having to think spatially to be a good designer. More definition is required. You must think spatially to be a good Industrial Engineer, true. But to be a good designer of mechanical systems, you can have all the spatial intuition in the world and still be a lousy "designer". I challenge you...adequatedly define the project or system:inputs, outputs, specifications, intentions and it can be designed with limited spatial thought. If you don't know where you are going, have fun wasting your time with spatial thought, with respect to mechanical sytem design.

Industrial Engineering / Design versus Mechanical Engineering / Design... That is the question!

 

[sancat]

Rampower, after reading your answer, you made me realize a previous step that I took for granted. You are right, first you have to define de problem to be solved and work out a solution or a set of solutions: "What" have to be "done", with your "machine", and then "How" your machine will make that. Lets say How many HP to be transported, or how many sand has to be moved or water pumped. Then after this "macro" part of the problem has been defined, you go to a 2D or 3D model. I prefer to hand draft on a big paper, because on the same paper I make pertinent stress, speed or whatever calculus, I don’t know how to do that on a computer screen.
Speaking for my experience, very seldom I have needed to use a 3D CAD; we have used it mostly for FEM design or for marketing purposes (to sell the solution to a client). Most times, when we actually make 3D CAD is made because our drafter knows how to do it, he finds it "cute", and he says that it is the only way to work details and to be sure nothing interferes (perhaps he is right about that).
However I disagree with you that spatial understanding is not needed for a physical model design. I think that without a spatial understanding of how things move, and what goes where, it is difficult to design a mechanical solution. It is most possible that you do it intuitively and take it as a normal capability. I have seen guys who just don’t get it, and while they might have a carton, they have lost their time at university. I also have seen people without studies, but with talent, and they make working designs. Their designs might not be so efficient in material use or conception, but they do what they are designed for.
sancat