How to extrude a solid with holes

jeff_mcaffer

I have a gear drawn imported as a DXF and added to a drawing (See the attached image). I can extrude the drawing as a "Surface" but when I extrude as a "Solid" just the outer perimeter is extruded. That is, there are no holes in the gear. How do I get this as a solid?  I looked at adding faces to the front and back but don't see how to do that either.  Basically I just want to "fill" the space constrained by the front and back planes.


W

3dcad

This is common problem with imported geometry, the shape must be cut in the place where it draws a line on surface. Try to hover the shape, does it select whole shape or just part of it?

It is pain to connect heads one by one considering that Onshape doesn't allow adding coincident constraint by selecting area with multiple endpoints. 

I would suggest using 'use/project' feature to replicate the shape in new sketch, make sure it's continuous and circular pattern the rest.

Good luck!

brucebartlett

@jeff_mcafferlooks like you've got it sorted, an easy mistake to make when starting out and ending up with surfaces rather than a solid. As @3dcad said it's worse when working with imported dxfs as they have no constraints.  

Tip: Once a line is black its full constrained. This is the way I like to leave my sketches, although you will find its hard working on imported geo.

If you have lots of gears to do it might be worth building a variable driven blank, once you have got the first one woking then do a copy of the tab and adjust variables to drive the new parts.  We are all here to help to get it going for you, we may even be able to collaborate on a shared doc for you.

This public doc may be a good start. https://cad.onshape.com/documents/c9a5ab9cc17f4a71b44f9828/w/fe9439076f8347d981a9c624/e/f8117c468d9249649a3ec575

jeff_mcaffer

I should add, when I extrude "solid" the center hole does extrude.  It is just the 5 spoke teardrop cutouts that do not extrude. The individual teardrops appear to be closed.

_Ðave_

Can you Share the link to your document?

NeilCooke

Hi Jeff - if all profiles are closed (shaded) then it should work. Try doing it in more than one operation i.e. extrude the teeth and center hole as one solid feature then extrude/remove the teardrop shapes as a second feature. 

3dcad

This is common problem with imported geometry, the shape must be cut in the place where it draws a line on surface. Try to hover the shape, does it select whole shape or just part of it?

It is pain to connect heads one by one considering that Onshape doesn't allow adding coincident constraint by selecting area with multiple endpoints. 

I would suggest using 'use/project' feature to replicate the shape in new sketch, make sure it's continuous and circular pattern the rest.

Good luck!

jeff_mcaffer

First, great community!  Thanks for the prompt help on a Saturday afternoon/evening.  Based on this info I looked *really* carefully at the original drawing (not done by me).  Turns out that all the segments of the teardrops are arcs and are not coming in as actually joined.  They just look very very close to connected.  I was able to get everything to work as expected by grabbing each arc end and moving it out/back so it snapped to the neighboring end.  Bit of a pain but in the end, it took a couple of minutes and is done.  I do have a lot of gears to do but its a one time deal.  Will look into @3dcad's suggestion when as the project progresses.
Thanks!

brucebartlett

@jeff_mcafferlooks like you've got it sorted, an easy mistake to make when starting out and ending up with surfaces rather than a solid. As @3dcad said it's worse when working with imported dxfs as they have no constraints.  

Tip: Once a line is black its full constrained. This is the way I like to leave my sketches, although you will find its hard working on imported geo.

If you have lots of gears to do it might be worth building a variable driven blank, once you have got the first one woking then do a copy of the tab and adjust variables to drive the new parts.  We are all here to help to get it going for you, we may even be able to collaborate on a shared doc for you.

This public doc may be a good start. https://cad.onshape.com/documents/c9a5ab9cc17f4a71b44f9828/w/fe9439076f8347d981a9c624/e/f8117c468d9249649a3ec575

jeff_mcaffer

Thanks Bruce for the help and the offer to collaborate. In this case the gears are all pretty specific and getting the dimensions will be more trouble than just tweaking the arcs to ensure they are constrained.  In general though I love the idea of a gear generator.