Design Engineering Resources 2

[gkan]

Hello everyone,

I am a mechanical engineer and my main occupation is the design and prototyping of lab automation devices. Most of these devices are intended for biological research, so I do a lot of fluid handling, laser systems, xyz stages, stirring and some magnetism. My trouble is, I was never really taught how to do what I do now. I mean, sure, I took all the courses that explain the science behind each technology and a couple of machine design courses but these were mainly focused on big machinery, power transmission, machine element analysis etc. I was never really taught how to design benchtop automation or instruments. I got "Precision Machine Design" by Slocum ,"Machine design" by Norton, "Mechanisms and Mechanical devices" by Sclater and some other books, but I dont really know of a book that is more focused on the process of design or actual examples of something more focused to benchtop automation engineering or instrument/device engineering. Surely there must be a book with examples of good designs from which one can draw ideas and methods and I was wondering if any of you knows of such a title.

Best Regards,

George

 

[GregLocock]

I think you are hoping for a rather unlikely resource. You might think that with circa one million people designing cars around the globe that there would be a Big Handy Book for Designing Cars. There isn't. There's a handbook with much important stuff in it, and a bunch of textbooks, but no single go-to book.

The usual way of designing mechanisms is to look at what other people have done.







Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

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[geesamand]

It's a tough learning process, no matter what your industry. If your own company has learned lessons, it's probably not well documented, and if a competitor has learned lessons, they have almost certainly not shared their solutions or aired their dirty laundry in a publication. If you haven't noticed already, periodical submissions coming from industry are always the success stories.

Even within one specific industry the best design method depends on your company strategy, where the new product will be relative to existing products, production quantity, level of standardization in the new product, time to market, liability / risk of failure, and many more factors. I find that since my company is relatively small and our new products don't sell huge quantities, that choosing the right prototyping experiments and justifying them is the hardest part. Choosing when to assume, when to calculate, and when to test for your information. Everyone outside of Engineering (including upper management) expects you know know what comes ahead on the development path and to have planned for it comprehensively. It is very important to understand the motivations and tendencies of the individual(s) that are making the go/no-go decisions on the project.

It never hurts to have a competitor's design on hand if you're designing something relatively new. Asking "why did they do that" is particularly instructive.

One area where I've seen perpetual failures in development projects is in the scope. It is vital to keep track of cost, required features, desired features, and development timeline. It's impossible to know the outcome but you can minimize your damage by constantly checking if the work is coasting off course.

David

 

[btrueblood]

Greg said "The usual way of designing mechanisms is to look at what other people have done."

Which is pretty true. I could only add, that if you want to be successful, find something that doesn't work well in the existing mechanisms, and then figure out a way to do it better. David's caution against scope creep is also valid...though sometimes it is inevitable.

 

[mfgenggear]

Work with a mentor, don't do it alone. if you do, expect failures.
looking at what has been designed, don't reinvent if possible.
have some one help with the design.

Mfgenggear

 

[imagitec]

Based on the systems you describe, I'd search for mechatronics books, web sites, and course materials (ocw.mit.edu has a mechatronics lab, but it's not in depth).

I don't own it, but Mechatronics: An Integrated Approach looks broad without being just a survey of components. It covers modeling and simulation as well. But it leaves out the fun stuff: architecture, system design, fabrication, and testing.

As noted above, no book will have everything. But I love books that cover those latter topics and are like having an old engineer who's experienced everything around, who has just the right story for every question (and they're always stories, not answers).

To that end, since you work with optics and lasers, I can't recommend Building Electro-Optical Systems: Making It All Work enough. It's a pleasure to read and there is useful information for every level and discipline of engineer who works with optics. There are extensive chapters on designing, building, and bringing up EO systems that together are the closest I've seen to what I described above.

Of more practical application than Precision Machine Design is Precision Mechanics, by Dave Kittell. It's sold by his son Jake, who I've worked with on a number of projects.

Building Scientific Apparatus is a survey of such topics as mechanics, vacuum technology, optics, and electronics. You're not likely to learn anything new in your field, but its a nice lab reference for other areas.

Rob
Imagitec: Imagination - Expertise - Execution

 

[Jabberwocky]

It's not specifically lab auotmation, and in fact seems to pre-date most mechatronic concepts but this book:

http://www.amazon.com/Machine-Devic...devices+and+components+illustrated+sourcebook

is a great read to flip through for inspiration on a mechanical linkage or interface you're working on.

 

[Jboggs]

I've been at this a long time and I can say that in the beginning of my career the best source of knowledge on how to design "stuff" was old drawings of existing equipment. I would study them and I would end up focusing on certain areas and asking myself "why did they do it that way?" Why that extra little bit of machining? Why is that component there? Look for the centerlines. They will tell you a lot about where forces and reactions and moments are acting. Look carefully at the "busy" areas of the drawing. That is where the most design effort went.

I learned another thing the hard way - when you can't understand why somebody did something some way that seems unnecessarily difficult and you try to do it more simply, you often painfully discover first hand exactly why they did it that way.

Some of the best sources of information, if you can find any, are old worn out PAPER catalogs. The more worn they are the better they are. They often included special engineering sections at the end that were usually very helpful.

Another thing you learn by studying old drawings is to respect the amount of effort a professional draftsman would put into making sure the drawing made a good first impression, was easy to read, was not confusing, and was thorough. Little things like line weight make a BIG difference in the effectiveness of a drawing.

And don't be afraid to ask for help and opinions from engineers and technicians you respect.