Offset all faces on body

[sofia]

Hi!

I have been reading up on this forum and tried to offset each part separately as well as together, the geometry is pretty simple and can't see what the problem is but it is the lofted side that are causing it. I need to offset all faces of the body by 0.2mm. 

I have attached the file here, please check.

Kind Regards,

Sofia

[LeonardoBN]

Hi @sofia.

I couldn't understand all your sketches, but I tried to reproduce your shape using Loft (two profiles and a centerline. My body deviated a little from your original shape, but I could offset its faces.

I attached here that file (I didn't constrained any sketches).

 

[sofia]

Hi Leonardo,

Looks like my reply disappeared so writing again:)

Thanks for giving it a go! However, the object needs to be created using the sweep tool since the object seen from the sideview should follow straight lines.

I redrew the object again but as soon as I use the sweep command the offset fails. Both path and guide rail are made out of simple splines so can't see why I get the error message. Can it be a bug? 

Is there another way to get around the error, as in making it a mesh and then offset it? After offsetting the object I will make a copy, place it so it connects to the original, join them and fillet the corners where they intersect.

Kind Regards,

Sofia

[LeonardoBN]

Hi. Are you going to use that inner spline? At first I thought that would be your Guide Rail.

I tried to redraw your geometry, but splitting into different sketches, in order to make it simple. I applied perpendicular constraints to the splines' ends, and it seems to work here from that point.

As I couldn't understand some of the geometry (like the two top circles, almost coplanar), I left them out of my example, and my shape may differ from yours in the top part.

I created the round end with an revolve instead of a sphere, and it seems to offset better.

[sofia]

Hi Leonardo,

Nope the inner spine was just a reference from an imported stl file. It should only be one top circle, I used it as a profile for the sweep. Sorry for being unclear regarding what part that is important to keep for the original, please see attached image of how the profile should be (following the construction planes).

Kind Regards,

Sofia

[KristianLaholm]

I could do Offset Surface (uncheck Chain Selection) on one "leg" at the time and stitch the Surface into one solid, from you file.
The problem in the geometry is in the connection of the 2 "legs", by doing offset one side at the time stitch then solves the problem.

[LeonardoBN · Accepted solution]

I could understand better now your intent.

I don't get along very well with 3D sketches, but I tried to fix some things in your original file, mainly in the first sketch.

I recorded a Screencast with my actions. Briefly:

1) I fixed the two circles and replaced some diameter lines, as I didn't want things moving freely;

2) I assured Coincident constraints between many points (you can see in the video);

3) As it seems to be the design intent, I applied Perpendicular constraints between spline and the circles (appropriated diameter lines). Both in your file and my previous attempt, this seems to make difference in the offset.

With those steps, the desired offset works well. I didn't need to change anything besides first and third sketches.

 

Screencast:

https://autode.sk/3hVhucQ

[sofia]

Hi Kristian,

Thank you for looking at it, it didn't work however. Did you check the original file?

Kind Regards,

Sofia

[sofia]

Thank you so much for this, it worked and I learned a lot. Great sketch practice:)

Kind Regards,

Sofia