Getting lost in the details...

[elardcase86]

Hello all, 

Hope that everyone has had a good Christmas/Holidays.

My question is in regards to workflow and the accuracy of modeling.

When you see models of what look like carbon copies of playstation control pads/tv remotes etc how do the people modelling these items get them to look so accurate!?

Do they usually work from factory drawings/moldings or do they simply work within a tolerance that isn't detectable by the average joe.... (me).

I use basic tools to measure such as digital vernier/steel ruler/protractor/tracing with pencil to figure out angles etc, but still find it difficult to get things looking absolutely 100% spot on.

I appreciate there may be no definitive answer but any advice/pointers would be much appreciated.

Many thanks

Daniel

[JDMather]

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@elardcase86 wrote:

I use basic tools to measure such as digital vernier/steel ruler/protractor/tracing with pencil to figure out angles etc, but still find it difficult to get things looking absolutely 100% spot on.

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Attach example file(s) here.

[elardcase86]

Thank you for the response,

Here is an example of the underside of a games console (nintendo wii).

I have attached images of both the drawing/model & the underside of the wii itself)

I am using Inventor 2013, I have attached the part file also.

Kind regards

Daniel

[elardcase86]

I could not get a good pic of the black wii I am using but here is the image of the part that I am recreating...

[JDMather]

First thing I noticed is that many of your sketches are not constrained.

You have many repeating dimensions that are not needed (pattern features rather than sketch entities, and in sketches use equal = constraints rather than repeating dimensions).

Do you have access to a Technical Drafting textbook (we use Giesecke,et al)?

I recommend that you start with a book with dimensioned drawings or some other source of dimensioned drawings.

Practice and attach your attempts here for suggestions on techniques.

Once you have mastered sketching and modeling from dimensioned drawings - then return to measuring and modeling objects from around your desk.   Pay attention to the slightest details - don't just keep plugging away adding features when you know a feature isn't right.  When you know it isn't right - stop.  Come back here and ask questions.

http://home.pct.edu/~jmather/SkillsUSA%20University.pdf
http://inventortrenches.blogspot.com/p/inventor-tutorials.html

BTW - have in installed all Service Packs and Updates for your version of Inventor?

On your Wii box, it is kind of hard to make specific suggestions unless someone has the box (I don't) in front of them.

[elardcase86]

Thank you for the reply,

I was under the impression that a fully contrained sketch turned a certain colour/cannot be moved, which of my sketches did you find unconstrained?

I have used pattern features before and produced models from drawings, I will have to look up the reading you suggested.

The equals sign you spoke of, that's only for radius/cirlces isn't it, and when you say pattern features are you talking of for example the four feet on the bottom rather than sketching them out each instance?

When you mention the repeating of dimensions that was purely to constrain the sketch, did you mean to use the fx function when the dimension was the same as a related one?

Kind regards]

Daniel

[JDMather · Accepted solution]

Any sketch that has not changed to a dark color or can be moved is underconstrained.

To me - that is like looking at a crossword puzzle that someone has done that has some blanks - an indication that they did not know some of the answers.  (the sketch will also display a thumbtack in the browser in later releases when constrained)

If you don't know something (a dimension) - find it out and add it.

The feet are all the same - model one and pattern the features.

Here is an example of a sketch that I find so disturbing to my sense of stability and robustness of sketching - that I have a hard time even looking at it --

I cleaned it up some - compare my cleanup to your original sketch.

First of all you were missing a Vertical (I have this shown laying sideways) on the long line at bottom of image above, therefore you had to add another 6mm dimension.  You are working too hard - Inventor should add this constraint for you.

I clicked on the short line above that to show some constraints that I added.  The Perpendicular constraint was already there (good, Vertical would have been good too - this was probably added for you by Inventor) I also added an Equal (=) between this line and the dimensioned line and added a Colinear constraint that also eliminated another dimension and preserves the design intent in editing.  Doesn't this area of the sketch "look" cleaner, less confusing to you?

Your original sketch (I grouped together the redundant dimensions) -

[elardcase86]

Thank you very much, 

That does look FAR clearer and I can see where you are coming from now, I will have a go at some examples/practice runs tomorrow.

Kind regards

Daniel