Trying to flatten surface for laser cutting, but holes from one sketch won't project.

david_fisher031

I am trying to get two surfaces to project to a plane to get dxf files for laser cutting. On one surface the holes are selectable and project fine, on the other they are not selectable. What is the difference between the two ?

The blue area is the surface I want to project to a flat plane.



This is as far as I can get.



Why can't I select the holes in the lower section to not extrude?

chris_8

It's a little confusing to me because I think you're mixing the terms Project and Extrude.  Have you tried creating a sketch on that upper plane, then using the Use/Project command to get the outlines of the holes and perimeter, then extude that new sketch?

NeilCooke

If you're trying to flatten the blue part you could use move face/rotate and rotate the angled flange around the axis of the bend by a set amount. 

brucebartlett

See this link for a method I used to flatten some parts but very time consuming. I am waiting patiently for some sheetmetal functionality to flatten bits like this for laser cutting.

https://forum.onshape.com/discussion/comment/12900#Comment_12900

chris_8

After reading @NeilCooke 's suggestion, I realized my idea would give you an incorrectly shaped part.  His idea looks like.a very good one.  

 Will your laser cutter make those chamfers for the screw holes, @david_fisher031?