GOODMAN HDS1200 DESIGN PART 1
Updated: Aug 7
When I was in engineering and had my own company I did several designs on computer this is an insight to that procedure on one of my designs.
This photograph is from the Barber museum in Alabama USA
Designing anything digitally or on a drawing board is evolution of thought, whether it be with pencil and paper or digitally, what you start off with is more often than not, not what you end up with, as the project progresses, so does your thought process, and your design becomes more refined and so it continues until you decide it is as perfect as you can get it and the best that can be done, years gone by before the digital revolution, design was confined to the drawing board and mathematical calculations obtained utilising a slide rule, today of course most people use a calculator for mathematical calculations, I used to do a calculation on the calculator and check long hand, believe it or not you can become number blind and keep putting the same error into a calculator and of course keep getting the same incorrect result, which can be catastrophic, I know I learnt the hard way, today it is achieved with sophisticated programs such as Autocad, Autodesk, which now has spin offs of Autocad Architecture, Autocad Electrical, Autocad civil 3d, which is used in a variety of different guises, mechanical engineering, falling into the category of cars, motorcycles, anything with wheels and much, more, Chief Architect is another that springs to mind, the giveaway is in the name and is used in construction, of commercial and residential, what these two platforms have in common is when being used, you do not compromise your thought process to achieve the best possible results, moving any project forward you start off with a GA (general arrangement) a view of the overall product, you then identify each component and mark them accordingly using a unique number to reference each component, this is then followed by detailing, this is the drawing of each individual component that makes up the GA, when using a drawing board that you have stood over for several days producing the GA, you will think of a modification to improve the overall design, whether it be aesthetical or functional, you are reluctant to erase a pencil line and move it as it will then have a knock on effect forcing you to then move probably ten more corresponding items which make up the whole, and of course takes a lot more time, digitally this can be done very quickly, however the thought process to develop the GA takes the same amount of real time, as the brain further focuses on the optimum of your design, the long and the short of it, designing digitally is far superior and tremendously quicker with no need to compromise, where as on the drawing board you would probably make the decision not to bother, if you take the average motorcycle it has approximately 3000 – 4000 different parts and every single part has to be either sourced from an outside supplier or manufactured in house, a typical car has 30000 parts, this in its self is a huge undertaking documenting each part and as the product is developed many parts will have revisions done to the drawings as each and every part has a drawing down to the smallest screw, with details such as material specification, heat treatment (if applicable) finish applied to the part (if applicable) in the case of a welded bracket for instance it will have a finish of maybe, zinc plate, powder coating, chromium plate each one of these finishing processes has specifications attached for quality control purposes as thickness of the Zinc Plate, colour of the zinc plate gold or silver and so it goes on, specifying weld types test procedures and other important parameters.
This brochure was produced by Goodman Motorcycles Ltd USA division Oklahoma
When it comes to laying out the parameters of your design, the most important consideration is how are you going to manufacture it, what are the different operations needed, what tooling needs designing and of course the most important is will it be economically viable, I was indentured for five years as a Tool and Die maker leaving school at fifteen years old, and started getting the skilled guys their morning sausage sandwiches from the canteen and their morning paper, after that cleaning out the toilet block was another daily chore, getting their cigarettes basically anything to get them through each day, after a year of doing all crap jobs, I was deemed to have achieved the right mind set to learn my trade, as I had been a typical know it all cocky fifteen year old, who in reality knew nothing and even less about life, I successfully completed my apprenticeship and after going to college, I became a competent engineer, so this experience stayed with me as I went into the design faze with my company Goodman Engineering, so when I did a design it was right with me every step of the way of how to manufacture each and every part, as easily and cheaply as possible, when I came to employ a university graduated design engineer, I found they were more than adequate for the design challenge but I found a lot of the designs were over complicated, expensive and difficult to manufacture, I soon went looking for people similar to my own background who understood the manufacturing process and sequences and this reflected in their ideas digitally on the computer screen.
This is me just taking the prototype out on test and entering the factory gate on return.
Of course not every design is a success, I remember when designing the handlebars for this project I had the idea to design a ball joint and socket so each bar had the ergonomic infinite adjustment for all riders position whilst sat on the bike, I had them made in my toolroom after completing the design, when the finished prototype landed on my desk, I burst out laughing at what an ugly large unsuitable load of crap it looked, and just threw it in the bin for scrap, that is one difficulty with designing using a monitor as it is difficult to visualise scale with other parent components, but I already knew that so there was no excuse (IFU).
When you undertake a project like this it takes several different key people who all draw on one another’s experience and knowledge, for design of product, and all necessary tooling for the manufacturing, although CNC (computerised numerically controlled) machine tools has removed some complicated jigs and now just need holding fixtures for the machines bed, we used to have daily meetings first thing in the morning just for half an hour or so to make sure we are all singing off the same hymn sheet.
Making the first prototype is a massive undertaking as you are giving birth to your very own creation, but where the problems really start is refining the design to be able to make the next hundred exactly the same, to the same standards and build quality, unfortunately for me I had been wired to a Toolroom mentality with precision at the top of my agenda, for example if I needed to drill a 6mm hole through 2 pieces then I would use 6mm drill with minimal clearance, in production you would drill one pieces 6.5mm and the corresponding part would have 6.5mm wide slot so they would always line up depending where the tolerances were lying on other associated components.
I hope I haven't bored you too much and you find this article interesting, I will follow up part 2 of designing and manufacturing The Goodman HDS1200 in my next blog.