Cannot Loft sketches

[stevsmith]

Im tring to create a sheetmetal loft from these 2 sketches but for some reason it won't work, does anybody have any advice.

15357401_ITM3.zip

[JD Mather]

I noticed that your 2D sketch is part of an arc but not continuous. Why is that?

Also I noticed that the 6 O'clock position is just off of the origin, why is that?

 

You cannot use Loft Flange to a 3D sketch and you would want the 2D sketch to be one arc.

 

Pull down the End of Part marker in attached.

 

It would have been even easier working from your original geometry rather than the geometry projected from another part.

 

My solution was done in edu version so after you see how I did it delete the file.

15357401_ITM3.zip

[stevsmith]

Thanks JD.

I had projected the line of the 2D sketch using project gemetry but the shape of the lid breaks away as shown in the sketch.

I had to use an old technique in sheetmetal by detailing projection lines to achieve the curvature and then used a cut on the flat development to get the desired effect.

[stevsmith]

I've just had a look at your file. I had a shot at the boundry feature but couldn't add any thickness to the material. Perhaps this is down to my in-experience in using inventor to this capacity. Thanks again JD, your help is very much appreciated.

[JD Mather]

Check the Thickness direction - I didn't know whether you were sketching the inside or outside.

[stevsmith]

Thanks JD, it was the O/side I was sketching.

[stevsmith]

JD, I have added the thickness to the part, turned it into a solid part and then converted it into a sheetmetal part. Added a rip to allow it to unfold but when I click unfold it says it cannot unfold it, any suggestions.

 

The file can be found at this link.

 

http://files.me.com/steven_smith/9b2a47

 

 

It is to large to compress, zip and upload to this site.

 

p.s, this is the goggles section that will be welded to the shown image.

[kencaz]

JD, I have added the thickness to the part, turned it into a solid part and then converted it into a sheetmetal part. Added a rip to allow it to unfold but when I click unfold it says it cannot unfold it, any suggestions.

 

I don't have 2011, however, from the looks of the above image It looks like Inventor would have a problems flattening that part for either a k-factor (brake), or constant roll radius (roll bend). may need to be die formed or maybe split into multiple parts for rolling. I'm not sure of any new 2011 features that you could apply for that.

 

If you did thicken and then convert to SM you may want to make sure your default thickness in Sheet metal Styles matches your part thickness or it wont unfold either.

 

KC

[JD Mather]

It is to large to compress, zip and upload to this site.

 

To get the file size smaller drag the red End of Part marker to the top of the browser hiding all features before saving and zipping.

 

I think this one can easily unfold but you must change your technique. Forget about 3D sketches - they are simply projections of 2D.

 

Forget about sheet metal for now. Model the entire assembly (using whatever techniques you know and attach here. I will reverse engineer and show you how I would model using the sheetmetal tools. I think you will find my method trivially easy.

[stevsmith]

Hey kencaz, I understand what your saying. I do have the default thk' the same as the surface thk' and it still didnt work.

Maybe by cutting it into 2 sections would work.

I'll have a bash at that.

[JD Mather]

Got it. I'll take a look and get back to you.

JD

[stevsmith]

Thanks JD.

 

Steven

[JD Mather]

Send me an email to jmather_at_pct_dot_edu and I will get you the file.

 

You've got mail.

 

For interest of others - looked to me like easiest method was to model as multi-body solid and then push out the individual parts.

[stevsmith]

Wow, It's easy when you know how,

I've never really used alot of the surfacing features. I'll guess that I'll have to look deeply into this. Especially since we get alot of imported parts from some of our customers.

On the part of the extrusion surfaces. did you use "split" to (in autocad terms) "union" the two segments together. Basically where the two points meet to create the surface of the lid?

I may not be wording this correctly, or describing it correctly. But I'm sure I understand the concept.

[stevsmith]

Oh, hang on I see it now.

 

You have created a surface using the axis and inserted an new plane to give you the angle. Drawn out the shape on the plane and surface extruded it. Then Sketched the base and extruded that up, then used a 3d projection and split the two surfaces to give the shape.

What is the deleted face?

 

For the goggles, you have extruded the sketch and trimmed away the inside using the surface of the casing. Am I right?

 

I'm going to head over to the AU to see if I can find any other handouts.

This greatly interests me. I think I'm hooked on surfacing.