Inventor General Discussion

Inventor General Discussion

Reply
*Expert Elite*
JDMather
Posts: 26,616
Registered: ‎04-20-2006
Message 11 of 18 (197 Views)

Re: Copying spline to a new work plane and linking to the original.

09-29-2013 05:43 PM in reply to: ghulands

Attach your ipt file here.

You should be able to edit sketches to correct missing connections.

Please mark this response as "Accept as Solution" if it answers your question.
-----------------------------------------------------------------------------------------
Autodesk Inventor 2014 Certified Professional
Autodesk AutoCAD 2013 Certified Professional
Certified SolidWorks Professional
Inventor Professional 2015 64-bit
http://www.autodesk.com/edcommunity
http://home.pct.edu/~jmather/content/DSG322/inventor_surface_tutorials.htm
Active Member
ghulands
Posts: 8
Registered: ‎08-29-2013
Message 12 of 18 (194 Views)

Re: Copying spline to a new work plane and linking to the original.

09-29-2013 06:12 PM in reply to: JDMather

Attached.

 

Thanks,
Greg

 

*Expert Elite*
JDMather
Posts: 26,616
Registered: ‎04-20-2006
Message 13 of 18 (186 Views)

Re: Copying spline to a new work plane and linking to the original.

09-29-2013 06:50 PM in reply to: ghulands

You are doing too much work.

You have 5 repeated sketches - these are not needed.

Your 3Dsketch is actually 2D, therefore I would do it as a 2D sketch.

 

I'll post my solution tomorrow.

Please mark this response as "Accept as Solution" if it answers your question.
-----------------------------------------------------------------------------------------
Autodesk Inventor 2014 Certified Professional
Autodesk AutoCAD 2013 Certified Professional
Certified SolidWorks Professional
Inventor Professional 2015 64-bit
http://www.autodesk.com/edcommunity
http://home.pct.edu/~jmather/content/DSG322/inventor_surface_tutorials.htm
Valued Contributor
CAG_DRAFT
Posts: 87
Registered: ‎07-30-2013
Message 14 of 18 (171 Views)

Re: Copying spline to a new work plane and linking to the original.

09-29-2013 07:59 PM in reply to: JDMather

I'm quite interested to see this, I've got a few issues with getting lofted surfaces to do exactly what I want.

Hopefully the solution JD posts is a 2013 file...

*Expert Elite*
JDMather
Posts: 26,616
Registered: ‎04-20-2006
Message 15 of 18 (151 Views)

Re: Copying spline to a new work plane and linking to the original.

09-30-2013 01:10 PM in reply to: CAG_DRAFT

CAG_DRAFT wrote:

I'm quite interested to see this, I've got a few issues with getting lofted surfaces to do exactly what I want.

Hopefully the solution JD posts is a 2013 file...


There is no one single solution for every Loft problem.

Since there were very few dimensions on the posted part - I made up my own interpretation (see attached file).

 

Notice that there are no extra workplanes and only two simple 2D sketches.

 

I recommend reading this document - particularly the section on fully constraining sketches.

http://home.pct.edu/~jmather/skillsusa%20university.pdf

 

Please mark this response as "Accept as Solution" if it answers your question.
-----------------------------------------------------------------------------------------
Autodesk Inventor 2014 Certified Professional
Autodesk AutoCAD 2013 Certified Professional
Certified SolidWorks Professional
Inventor Professional 2015 64-bit
http://www.autodesk.com/edcommunity
http://home.pct.edu/~jmather/content/DSG322/inventor_surface_tutorials.htm
Active Member
ghulands
Posts: 8
Registered: ‎08-29-2013
Message 16 of 18 (134 Views)

Re: Copying spline to a new work plane and linking to the original.

09-30-2013 06:09 PM in reply to: JDMather

Hi JD,

Thanks so much for doing that. I think my problem boils down to three things

 

  1. Not knowing the best way to break down the final geometry I was after into a minimalist form.
  2. Not knowing the best sequence of commands to achieve the final geometry. Is there a rule of thumb in Inventor like arthimetic operator precedence (eg. multiple before addition)?
  3. Good 2D sketching skills. Along with doing the tutorials on your site, I also bought the Learning Autodesk Inventor 2014 DVD which did help me a lot from when I first tried to sketch the fuselage. That DVD also made clear that having a fully constrained sketch is important.

I just went back to my sketch to try to constrain the the main fuselage shape and was still not able to, so I just wanted to ask a couple of questions on how you did that sketch. Did you create half of the sketch and then mirror it (I know you recommend against mirroring but not sure if mirroring a spline is an acceptable use of it)? What is the significance of the points down the center line? What does placing a work point on the XY plane help with?

 

For sketch 2, was the reason you dimensioned it with the diametral dimension and depth, instead of dimensioning to the arc point (like you did on the arc marked 600) because you knew you were going to revolve the nose?

 

I think as I use the application more I will get more fluent on the 2d sketching, and a better understanding of the interaction of operations to better sequence the commands to achieve the final geometry in the least amount of steps. At the moment I think learning the rationale behind why you did certain things will go a long way to help the later one.

 

Thanks again for your help, JD, I really appreciate it.

 

Greg.

*Expert Elite*
JDMather
Posts: 26,616
Registered: ‎04-20-2006
Message 17 of 18 (121 Views)

Re: Copying spline to a new work plane and linking to the original.

09-30-2013 11:03 PM in reply to: ghulands

The first identification of geometry was easy.

If the profile doesn't change - then Extrude the feature.  Only one sketch needed.

 

More or less -

Extrude or Revolve, Hole, Fillet, Chamfer (Fillets and Chamfers as late as possible).
Sweep, Shell

Loft

Bend Part

Surface modeling

...but not hard and fast rules.  Often (quite often) I will start out with surface modeling simply becuase it is the shortest, least amout of work towards the finish.  Many think they have no need for surface modeling becuase they don't do curvy, organic shapes.  I have a collection of examples of simple geometry parts that are just easier to complete starting out with surfaces.

 

Mirror of sketch points in this problem would have been just as good as what I did.

I created a bunch of horizontal construction lines out in space and then added Coincident Midpoint constraints to constrain to the vertical line - the same as mirroring points.  DO NOT in most cases) mirror a spline.

 

The workpoint was to define the pierce location of the spline and the YZ plane. If you zoom in on that location you will see that the construction geometry and the spline intersect the YZ plane at slightly different locations because a Control Vertex Spline was used rather than an Interpolation Spline.  If an Interpolation Spline had been used - the Work Point1 would not have been needed.  It is coincident that the workpoint also appears on the XY plane (because the 2D sketch spline is on the XY plane.  The significance is the pierce of the YZ plane of the spline at that point.  That gives me a point to connect the Rail in Sketch2.

 

The diametral dimensions could have been dimensioned as radii, but when creating 2D drawings from the model - I can Retrieve the diametrals which I probably want in the 2D documentation.

 

Practice, practice, practice and get lazy - do a part and then do it again using what you learned from first attempt to simplify.  Over time you will learn to simplify from the start and realize you were doing too much work in the past.  Get lazy.  Figure out the easy way to aviod work. 

 

I'm sure if I re-did this part I could simplify my initial attempt - I did too much work on Sketch2.  I did too much work on Sketch1 - it would have been fewer clicks to create the points and mirror rather than add midpoint constraints to a bunch of construction lines.  But when I did Sketch1 I was still trying to figure out your design intent.

 

It is often better to loft between solid and/or surfaces rather than sketches - as there are more options for control.
If I remember - tomorrow I will post a link from an AU 2012 presentation which is very good for understanding how Inventor creates your geometry.

 

 

  

Please mark this response as "Accept as Solution" if it answers your question.
-----------------------------------------------------------------------------------------
Autodesk Inventor 2014 Certified Professional
Autodesk AutoCAD 2013 Certified Professional
Certified SolidWorks Professional
Inventor Professional 2015 64-bit
http://www.autodesk.com/edcommunity
http://home.pct.edu/~jmather/content/DSG322/inventor_surface_tutorials.htm
Active Member
ghulands
Posts: 8
Registered: ‎08-29-2013
Message 18 of 18 (94 Views)

Re: Copying spline to a new work plane and linking to the original.

10-03-2013 09:23 PM in reply to: JDMather

Thanks for some insight into your process - it helps a lot.

 

I started to model a servo the other night and it doesn't look too bad - but it definitely could be a lot simpler. That will be this weekends task. And then I'll take another stab at the fuselage.

 

Thanks for all your help.

 

Cheers,

Greg

 

Announcements
Are you familiar with the Autodesk Expert Elites? The Expert Elite program is made up of customers that help other customers by sharing knowledge and exemplifying an engaging style of collaboration. To learn more, please visit our Expert Elite website.
Need installation help?

Start with some of our most frequented solutions or visit the Installation and Licensing Forum to get help installing your software.