topic Re: Automatically dimension and constrain sketch in Inventor Forum

Automatically dimension and constrain sketch

Anonymous — Thu, 16 Jun 2016 17:42:23 GMT

Whenever I have a problem to make a sketch fully constrained I use this button to constrain a sketch fully. So far it has not failed. I wish to know whether it is advisable to use this button. Help topic has very limited information about what I need.

Re: Automatically dimension and constrain sketch

JDMather — Thu, 16 Jun 2016 17:50:16 GMT

Forget that you ever saw that button.

Drag points and figure out what is needed.

Then you will no longer have this issue as you will have learned how to properly dimension and constrain a sketch.

Re: Automatically dimension and constrain sketch

mcgyvr — Thu, 16 Jun 2016 17:52:06 GMT

I believe its always best to manually dimension and constrain (any constraints that aren't automatically inferred already) everything yourself.

But I have used that button a few times..

I would never recommend a new user presses that button..

Re: Automatically dimension and constrain sketch

swalton — Thu, 16 Jun 2016 18:00:42 GMT

I don't use the automatic constraint/dimension button.

Instead I use the following:

Project geometry that I need from the model origin or previous features. Keep this to a minimum.
Draw the sketch geometry that I need.
Confirm the automatic sketch constraints and add new ones as required.
Add dimensions to control the geometry.

Each step requires thought about my design goals, manufacturing requirements, company standards, how I expect the sketch to change as my design evolves over time, and how to structure the web of geometry, constraints and dimensions so that someone else can understand my model at a glance. You will get better at considering all these factors as you gain experience with the tools. I use a similar set of factors as I place and constrain components into assemblies.

I don't use the automatic constraint/dimension tool because it has no knowledge about all the above factors.

Look for the "Show All Degrees of Freedom" command from the Right Mouse Button menu while in a sketch. That will show you the remaining DOF in your sketches and give you some direction for additional dimensions and sketch constraints.

Re: Automatically dimension and constrain sketch

Anonymous — Thu, 16 Jun 2016 18:04:23 GMT

Problem is sometimes sketch is dark blue colour that means sketch is near to fully constraint but down right corner side of the window shows still couple of dimensions are needed.

Re: Automatically dimension and constrain sketch

tschaeferZNBXX — Thu, 16 Jun 2016 18:06:20 GMT

I have NEVER used that button and STRONGLY advise you not to. Using this button will make your life more difficult and hard to trouble shot any issues you have if the sketch gets sick.

If you understand the part you are make or sketch you are making there should be no need to use this button. It could add dims or constraints that mean nothing to your design but satisfy the criteria for a sketch to be fully constrained/dimensioned.

If you are learning Inventor or CAD why are you not asking your instructor? Seems like you always ask the forum but get defensive when people try to help you.

Re: Automatically dimension and constrain sketch

Anonymous — Thu, 16 Jun 2016 18:20:37 GMT

If you are learning Inventor or CAD why are you not asking your instructor? Seems like you always ask the forum but get defensive when people try to help you.

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It was my instructor told me use this button.

No demand here, only request. Choice left to mentors.

Sometimes help sometimes opinion. This is merely an opinion.

Re: Automatically dimension and constrain sketch

swalton — Thu, 16 Jun 2016 18:15:52 GMT

Use the Show All Degrees of Freedom tool or JD Mather's vertex drag suggestion to learn where you missed a dimension or constraint. Once you know what geometry is under-constrained, add dimensions/constraints to tie it down. Don't just slap a dimension on a line, think about how that dimension will be used later in the design process and the life of the product.

Re: Automatically dimension and constrain sketch

JDMather — Thu, 16 Jun 2016 18:24:05 GMT

@Anonymous wrote:

...It was my instructor told me use this button.
I don't know whether to or or get ....

But the fact is - I seem to recall having covered this topic many many times, including videos. I could be wrong, but ....

Did you see me stop - dazed and confused at 4:45 in this thread? I expected the line to be constrained. How did I solve my confusion?

Re: Automatically dimension and constrain sketch

tschaeferZNBXX — Thu, 16 Jun 2016 18:18:45 GMT

Just seems lazy on their part then.

I would suggest putting your own dimensions that actually mean something that you can then retrieve when creating the drawings. It will speed your drawing creation up greatly.

Re: Automatically dimension and constrain sketch

Anonymous — Thu, 16 Jun 2016 18:31:24 GMT

But the fact is - I seem to recall having covered this topic many many times, including videos. I could be wrong, but ....

------------------------------------

Yes you covered many times. Particularly when I have a problem in examination hall myself has to solve the problem. When the time is limited I have to look for alternative methods. Because exam is mark oriented not knowledge oriented.

Re: Automatically dimension and constrain sketch

tschaeferZNBXX — Thu, 16 Jun 2016 18:30:19 GMT

Ok so you are using the forums to answer your questions while you are taking an exam?

Re: Automatically dimension and constrain sketch

JDMather — Thu, 16 Jun 2016 18:32:01 GMT

In my experience having taught hundreds of Inventor users - the single most important concept might be to drag endpoints when sketches don't become constrained as expected (and there should be a logical expectation).

...and we haven't even started on Design For Manufacturability issues yet.

When does your class end? It won't matter how good you are with Inventor if you never learn DFM right long side of the design tool. In my experience if this isn't learned at the same time - students get stuck on ~~designing~~ modeling perfect parts that cannot be manufactured.

Re: Automatically dimension and constrain sketch

Curtis_W — Thu, 16 Jun 2016 18:39:31 GMT

@Anonymous wrote:
Problem is sometimes sketch is dark blue colour that means sketch is near to fully constraint but down right corner side of the window shows still couple of dimensions are needed.

Hi fiatnm ,

In the Automatic Dimension tool you can un-select the Dimensions check box and let it only put on only sketch constraints.

I do use it this way occasionally.

Like everyone else has said, I do not recommend using this tool as a matter of common practice. If you develop proper practices and good sketch and constraining skills the need to use this tool to apply constraints will only arise when trying to work with someone else's poorly sketched mess.

In this picture it says 2 Dimensions required, but in reality it is 1 sketch constraint.

I hope this helps.
Best of luck to you in all of your Inventor pursuits,
Curtis
http://inventortrenches.blogspot.com

Re: Automatically dimension and constrain sketch

Anonymous — Thu, 16 Jun 2016 18:41:11 GMT

..and we haven't even started on Design For Manufacturability issues yet.
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My college is thinking to discontinue teaching inventor and going to start Solid Works which is very much popular among employers.

Re: Automatically dimension and constrain sketch

tschaeferZNBXX — Thu, 16 Jun 2016 18:45:10 GMT

Has nothing to do with what software it has to do with how to design something that can be produced in the real world. I can make many things in Inventor/Solidworks/ Pro -E but they are not able to be produced.

Re: Automatically dimension and constrain sketch

Anonymous — Thu, 16 Jun 2016 18:51:38 GMT

Thank you.

Re: Automatically dimension and constrain sketch

JDMather — Thu, 16 Jun 2016 18:56:35 GMT

@Anonymous wrote:
..and we haven't even started on Design For Manufacturability issues yet.
---------------------------------------------------

My college is thinking to discontinue teaching inventor and going to start Solid Works which is very much popular among employers.

I also teach SolidWorks. There is essentially zero difference between the two programs (until you get to advanced topics like Dynamic Simulation).

The DFM has nothing to do with software used.

But teaching of both the software and DFM issues assumes expert experience in both. This is a professional field of study and deserves a professional level of preparation. There is no magic software button.