Machine design tutorials 2

[tortiman]

Hi all. i´m an electrical engineer, I´m interesting in learn how design a machine, mechanical part.I have been searching in the web but I haven't find nothing interesting. I've found mechanical books that are fine, but I search sketches of machines, books, websites or forums where find more detailed information. Do know anybody something about this?

Excuse me for my english.

 

[cloa]

That's very general- what specific type of machines are you searching for?

 

[tortiman]

Hi Cloa, isn't a specific type of machine, is the design process. How make the first skecht, what database of parts use,... It's know how work a designer. If a customer tell you, if you are a designer, that you must make a packaking machine, how will be the complete process of design. this is I want to know. Thanks.

 

[chicopee]

Well,you can first start checking out some older versions (1960's and prior years) of mechanical drawing textbooks. I say 1960's because I had mechanical drawing in college back then and I remember the machine parts that we had to draw. I have no idea about the newer textbook versions.

 

[tortiman]

Hi and thanks chicopee, is a good start see mechanical drawing textbooks, but I would like talk to with a machine designer. Nobody is it?. I understand that in the machine design process working some engineers and perhaps is difficult find a person that he design totally a machine. An example I`m searching could be a homemade cnc like this.

http://blog.bricogeek.com/noticias/diy/video-planos-de-router-cnc-en-sketchup/

this is an example there are much more. Well I'm searching something like this but another machines for.

 

[KENAT]

Design 101 - "Know thy requirements" (explicit & implied)

The rest falls out of that, more or less.

There are dedicated machine design books that may help. For instance I have "Precision Machine Design" by Slocum. May be a bit too precise for you but it does have stuff in it about the design process.

Beware though, while it covers machine design it, like many similar texts, assumes you have a reasonable understanding of fundamentals.

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http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
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[gadkinsj]

two books I own and would recommend.

TECHNICAL DRAWING by Goetsch & Chalk

FUNDAMENTALS OF MACHINE COMPONENT DESIGN by Juvinall & Marschek

I recommend those because those authors have been doing these types of books forever and they have been sorted through several editions.

Most component company's have very good cad models of the products they make, so 3-d modeling is much less time consuming than is used to be.

As a process.
I figure out what it needs to do.
I usually start by doing a basic layout with squares and circles for where components should go so I can get a feel for what the end product might look like.
I look at what I could buy off the shelf to accomplish it.
I figure out if half a million dollars in design time is going to get something better than what I can buy.
I go buy something and spend a million dollars getting it to work as its specified.

 

[TED7]

gadkinsj - The last step is realising your client informed you of the large loading bay door (which you designed accordingly for) but ommited the fact that there is a much smaller door between there and the destination.

This door will be in a wall which will almost always be a structural.

Will Walters
Sheffield UK
Designer of machine tools - user of modified screws

 

[tortiman]

thanks for the information gadkinsj, I'll see the books. But there aren't web sites or forums where machine designers discuss about machine design, it's a question. The interesting, I think, is find a complex machine example that show the process of design, the mechanical design, electrical design, hidraulic design, pneumatic design, ...., not the design of an insulated part.

 

[imcjoek]

You won't find exactly that because there are many ways to do it.

The design of the machine *is* the design of an insulated part, iterated over and over, as each part ruins the design of the previous one.

 

[tortiman]

how????? iterated over and over, any example?

 

[gadkinsj]

3d design tools and top down design are a good way to sort through the iterations and keep the number of accidental interference/mismatches down to a minimum.

My company uses Pro-E currently but we are part way through a shift to Catia so i have some experience using both products. I'm sure that most other 3d programs have the means to do top down design. As a comment, Pro-e is easier to create drawings and Catia is easier to create models. Both have a learning curve that is steep at the beginning.

One of the most important considerations at this point is, what is your design criteria. Who is your customer and what is important to them. My customer is my own company as we design out own machines. Our most important consideration is down-time, so we spend extra money when the decision between longevity vs cost, or make sacrifices in floor space when it makes for easier removal/installation of known wear items. If you don't know whats important to your customer when you start then you may make poor decisions in the design phase.

Our usual process is to have 1-4 mechanical design engineers working on a machine about the size of a house with several hundred uniquely designed parts several thousand purchased parts a large framework and a 8-12 month design cycle. The most effective way to do this is to start with a skeleton model that everyone gets a copy but only 1 person has control over. As design changes are made at the skeleton level everyone updates it. If you attach your design parameters to the skeleton, your parts update accordingly with each iteration.

Our machines can be broken down into "stations" so it is easy to break up the work and the skeleton model has the floorplan information, the axis's(how do you plural that?) of movement, and a basic sweep of the mechanisms. As we complete our individual bits of the machine it gets put into a model that includes the skeleton so all the indivdiual sections find their home on their own.

We create a schedule of I/O that gets handed to a group of electrical engineers and basically their work is done while the mechanical parts are being fabricated. When the parts are done being fabricated the electrical engineers have informed us of the various IO box's sensors ets, that are required for the control of the machine, we put those into the model and generate a final layout drawing that includes panel placement, cable ways and flexible cable paths. Our electrical engineers also handle basic pneumatic design but if it gets complex we farm that work out. We have completely eliminated hydraulic power from our machines as it is messy and electric cylinders can fit into almost every place that formerly would have require hydraulics.

Then an Electrical Engineer and I go and have fun putting together this giant jigsaw puzzle with whomever we contracted to do the work. We have a mechanical and electrical on-site for the last few weeks of assembly and then another couple weeks as you work through the constant minor and sometimes major issues that arise in a complex electical/mechanical assembly.

As a comment, This is virtually unchanged from the way things were done at this company before the advent of 3-d modeling, but instead of a couple design engineers, it used to be 2 engineers and 5-15 designers with an 18-24 month design cycle.

 

[unclesyd]

You need to look over the materials and courses offered by Tooling U. I would give the ma call to wee what the offer in package deal for machine design.

http://www.toolingu.com/class_search_catalog.aspx

 

[engineer4fun]

You won't find exactly that because there are many ways to do it.

The design of the machine *is* the design of an insulated part, iterated over and over, as each part ruins the design of the previous one.

I agree with this, there are simply to many variables to get an exact design.

Designer and <a href="

http://www.coilingtech.com/compression-springs.html">compressing

springs</a> enthusiast