Creating Shell of Complex Lofted Shape

[colemanHEXZG]

Hey there! I'm trying to figure out a way to create a shell with a thickness of 1mm and a clearance within it, so the shell can fit over the body that the mesh is created using. I would ideally love to just scale the body to grow uniformly by 1mm and then just use the shell command, however the shell command is failing when I try and use it. I also have tried to copy the body and then scale the exterior body and do a Boolean subtract using the smaller body, however the scale command isn't scaling uniformly from the center to allow me to easily do that (some parts are thicker than others). 

Is there a better workflow I should be doing to fix this or something I'm missing? 

[colemanHEXZG]

Thank you for the help it truly has been beneficial. Is it best practice to keep everything on one thread or to start a new one once I've stepped forward to the next sketch or part of the design?

Also in this design I'm not sure if I had made this clear previously, I do have a cover in my hands that I can measure which is the goal of reproducing. Recreating the interior, however, is the main issue. Do you agree that the best workflow is most likely going to be creating a large number of section sketches and then lofting between all of them, ultimately to shell out the design thick enough?

I'm interested in the course if you believe it would be beneficial. I have looked around for some good documentation or tutorials on YouTube, however, they seem very surface-level and basic, so I'd be ideally looking for something more advanced as I believe that I understand the tools, but not how to expertly utilize them. 

[colemanHEXZG]

Attaching the new .F3D file as I have now started over and created two sketches. My main question is with the spline as I don't generally know if that is the best method to approach this or how to correctly dimension.

I believe that I am going to have to use the section sketches to loft the body and then create a rail on the outside of the mesh as well to help aid the loft. Is this most likely the correct workflow to work through?

[TheCADWhisperer]

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@colemanHEXZG wrote:

Also in this design I'm not sure if I had made this clear previously, I do have a cover in my hands that I can measure which is the goal of reproducing.

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I misunderstood, I thought you didn't have access to actual part.

I don't know what I am looking at - some photos might help.

6mm is pretty small.  Is that the actual measured size (measurement doesn't have to be perfect)?

[colemanHEXZG]

Yes, I have the physical cover which I am reproducing, however, I do not have the object the scan is of which this cover will go over. I've attached some images of the cover.

Regarding the size at the top, I believe I could make it slightly larger (maybe 7mm) but the actual top face of the cover is very small. 

Also, I want to note the entire cover has a thickness of 1.5mm so my internal dimensions would be 3mm less than the total width or length. There is the option of modeling this from the outside by matching the dimensions of the outside of the cover and then shelling inward instead of outward. I was trying to do the interior dimensions since that should be closer to the scan's dimensions. 

[TheCADWhisperer]

@colemanHEXZG 

I do not see a Workplane for your second sketch?

There is plane for the first sketch, but not the second?

[TheCADWhisperer]

@colemanHEXZG 

Mirror of Splines often does not work out well, especially on editing (which we will likely have to do).

And mirror not needed.

[TheCADWhisperer]

@colemanHEXZG 

Your second sketch should look something like this before even creating the first Spline.

There is a Midpoint constraint between each Horizontal line and the vertical line.

But don't use the Midpoint constraint to create these constraints.

Instead use the Coincident Constraint, select the Vertical line and then Shift select midpoint of first Horizontal line. (constraint glyph will show as midpoint in your sketch, but not shown in my image above)

Add logical dimensions. (My dimensions are not logical (shouldn't go past one decimal place and at this point probably integer) and shown as reference dimensions in parenthesis while your dimensions will be driving dimensions.)

Repeat for next line.

[TheCADWhisperer]

@colemanHEXZG 

At some point someone is going to jump in here and show their technique.

I'll go ahead and break the news to you that I am going to do the model quite differently in the end myself, but going down this road is important to arriving at final destination, even if this road turns out to be a dead end.

[colemanHEXZG]

I was using the section sketch as the plane to create the sketches. The section sketch allows for a similar workflow as to that of an offset plane but just gave me something to look off of when sketching.

[TheCADWhisperer]

@colemanHEXZG 

Create workplanes for sketching.

Section Sketch (especially for rough geometry like this) is only for reference - not for serious modeling.

[colemanHEXZG]

@TheCADWhisperer Thank you so much for this tutorial. I will try this as I'm redoing this sketch and try it with 1-2 more sketch profiles to see if I have gained any improvement. Thanks again for the insight and the help. It truly has given me direction where I had none previously.