BY Profession i am an engineer, and am intrested in designing machines using CAD, I would like to start with very simple projects. Please guide as how should i start?

If you wish to become a useful, professional engineer, building a career around designing and building machines, the first thing to get into your head is the fact no CAD software designs anything. The designing part comes from the brain of the designer. CAD software is just another tool an engineer uses in the design process. Many great engineering designs have been produced well before the invention of computers and any CAD tools. Other, and probably more important tools, would be, the knowledge of how machines work, the basic physical laws of the world the machine is to function in, the basic physical properties of the materials you will use to make the machine, the ways the parts of the machine will be made using the tooling and workshop facilities you have available to your project.

We, before we even bother to turn on our computer and start up our CAD application, need to work out the basic specification that applies to the design of our particular project. In the case of the simple see-saw, this would start off with the range of mass of the persons that will use this see-saw, the physical space that the machine is needed to operate within, as this helps to determine some of the actual dimensions of our machine. In the case of our simple see-saw, CAD software can't do this by itself, we need to tell it what we want it to do. Once, we the engineer, have a basic workable design in our head, or written down on a piece of paper, we can convert this design into a model of our possible design, using our knowledge of the tools provided by the CAD software. Once we have created this model, we can then often make a simulation of our see-saw in our CAD software that we can use to check how well our model see-saw will work with respect to our original specification, before getting the real one made.

In the case of the second project you mention, a simple crane, no customer is going to ask you to design one, then after you have finished, let you work out its capabilities afterwards so you can then tell him what he can use it for. If you are commissioned to design a crane, you will start with the specifications the machine will be designed and built to. The customer will come to you with the basic specification for the crane they require. It will need to be able to lift safely up to a maximum weight and be able to operate with this design specified weight within a physical space. You use this specification to work out the basic parts of this crane, required motor power the rough sizing of many of the parts you will use , some of the commercially purchased parts, bearings, cables nuts bolts and the like, you will search through the catalogs from the suppliers and manufacturers for the dimensions of these components. Before the internet, and useful CAD software this could be a big part of the design process. The internet and on line catalogs along with downloadable 3D models of these parts has streamlined this part of the process. Once we have the basic design concept, much of this worked out before we got out our CAD opened up, we can start making a basic model of our design using the CAD tools available to us. The CAD tool makes it possible to look at possible alternatives to our original concepts to our design as we work through it. This is where we can extract the value from our expensive CAD tool. With well constructed models and modeled assemblies these models can be efficient and flexible.

As we develop our skill with these tools we can connect our parts to spreadsheet programs, use our engineering knowledge to do complex design calculations with the results driving the dimensions of our modeled parts. Once we become reasonably proficient with the tools available to us we can use these tools to streamline much of the design and manufacturing process.

My point of view is the word " design " is often used out of context here on GrabCad, producing a model, of a physical object, be it by accurately measuring it, then modeling it with your CAD software, or dreaming up some random object and producing it as a model is just modeling an object. Designing applies to coming up with an object that we have created to perform satisfactorily in a real world. We design this object then use our CAD tools to model this digital representation model of our possible real world object. We could not bother to produce a model of this object we have designed and if we have designed this object go out into our workshop and just make one. If our design is good, we will end up with the physical object that we can actually make and it will perform as we intended it to. The word " design " should be used in this context, something we have conceived, will work, and is possible to actually make. The rest is just modeling, and is not actually designed by us or work, or even to be manufactured necessarily.

I have been involved with engineering and manufacturing since 1971, and a lot has changed over those years. We used to have rooms full of draftsmen working at drawing boards. Engineers would bring in sketches that the skilled draftsman would turn into drawings that could be used to build the finished product. Much of the more junior draftsmen would be just copying these sketches. The more experienced and better draftsmen would, after gaining more advanced engineering knowledge and passing the right technical exams would be presented with a more basic sketch or even work out a design from just the specification producing both the manufacturing process and the design calculations to validity the design. The fully qualified engineer leading the project was too valuable and expensive to be wasted spending hours at a drawing board 2D CAD moved into the drawing office, and then less workers could produce the quantity of drawings required so drawing officers became smaller. The big revolution was the development of good, relatively easy to learn 3D CAD software. This could be made good use throughout the whole design and manufacture process. Now it became economical for the more expensive experienced and university qualified engineers to take on some of the CAD work as part of the design process, and in smaller organizations this has also taken over the drafting function as well. This has altered the whole engineering profession. Many university engineering courses now instead of being focused actual engineering are becoming centered around CAD toys instead of engineering, too much emphases placed on playing with CAD ahead of good sound engineering knowledge. CAD is getting easier and easier to learn an become proficient. more time should be spent on actual engineering. The CAD tools can't think, engineers do the thinking, CAD can only does what it is told to do, if told rubbish the output will always be rubbish. Good design comes from the knowledge and experience inside the head of the designer not from your CAD software. A bit of time practicing and learning CAD, is all that it takes along with the right sort of mind, the same type of mind a good engineer needs, to learn to use CAD, the ability to think logically, being able to work through most problems by starting at the beginning, working through to the end in a step by step application of knowledge to reach the end, and a successful conclusion.

Not everyone is suited to this engineering profession, and passing exams does not necessarily make you a good engineer, a passion for engineering, hard work and an ability to understand how things work and how to imagine new possible solutions that this knowledge you have can be applied to, to find solutions to engineering problems. Sometimes you can work long hours for little reward so don't become an engineer just for the money, become an engineer because that is what you like to do and be prepared to spend a bit of time to develop your skills. CAD is one of those useful skills. When I started to become proficient at making good use of CAD skills I went to the local Technical College and completed a basic AutoCad course. Before i started this course I had been introduced to an old DOS CAD program Generic CADD 6.0 and with a bit of practice after work in my own time after work, I taught myself how to produce usable drawings from this program. This time I spent and the results I had achieved encouraged my employer to send me on the AutoCad course. In the final week of the course I spent the weekend helping with a rush job on contract to produce the finished drawings for a project. Over that weekend I learned more about making good use of that software by working alongside good experienced ACAD techs than I had over the 3 week course. I have found that working with skilled men, and an inquiring mind, a knowledge of how things work a way of learning, better than most of the paid for CAD courses I have attended. Other than the two ACAD courses my employer, at the time sent me on, the only other paid for CAD course I have been on was a Solid Works Advanced Fabrication course my employer sent me on about a year after I first started using this product, part of a package from the sales man that had talked the company into to purchase more SW licensees. I had been using Solid Edge, which I learned myself before Solid Works. It is not that hard to learn how to be productive with most of the common 3D applications as they are quite similar.

If you wish to develop into a useful designer, learn good design first, then learn to make use of CAD to produce those designs. Why don't you say, design a basic Jib crane that can lift say, 1,000 Kg, work out motor required, shafts, bearings and other components, that can be actually be manufactured, produce a workable model, analyze the resulting model the post it on GrabCad. If you have little experience, this may take some time but the best way to go is to try, we learn most things by giving it a go, we learn to walk by crawling first, and we fall over a few times at first but with effort and persistence we get there. For all of the skills we have learned effort and commitment is what gets the results, there are no shortcuts effort is the key to success.

I have ranted on on this straight forward topic, nearly producing a novel, but this is a symptom of several weeks of the covid-19 isolation now having run out of things to until i can get back to working on vintage trams and adult literacy classes that normally occupy me.