Removing an "asymmetric Pyramid from solid" (Constructing a hip rafter)

joerg_arnold

Dear All,

I'm kind of new using Onshape and got stuck by trying to construct a hip rafter for an awing (shown in the picture below). 

My Problem is the following:

I have created a balk as a solid in Onshape. Now I have to remove some kind of an "asymmetric Pyramid" in such a way that the hip rafter fits to the corner of the two horizontally aligned balks (red circle, picture below on the right) .
How can this be done in Onshape? 

                                                                       
Hope that I explained the problem clear enough...
 
I am thankful for any help and information!
Thanks!

owen_sparks

Ok, here is a copy of your file:-

https://cad.onshape.com/documents/ff6546867121648627049b8c/v/5f821257573d35ab3d0d5043/e/ebfd0e0949a6783a66fd8168 

You'll see I've:-

(1) Changed your extrude2 to "New" from "Add" so that it creates a separate part.

(2) Added a boolean feature to cut away the new part from the old part.  (I've added an offset to give a tolerance with the offset face option.)

Does that help?

Cheers, Owen S.

TimRice

If all of the parts are modeled in one part studio you could use a Boolean feature to use the other rafters to subtract volume from the hip rafter. Feel free to share the document url here and ensure the document is Public and we can take a look.

joerg_arnold

Thanks for the fast reply! 
Here is the document url:

https://cad.onshape.com/documents/ac36b4c9dcb9af7d189aae9b/w/bcab52b58daa7cc952da01bc/e/48a3d210a5866b7a9915b4e4

Yes, I wanted to try the Boolean feature, but had problems to find the right workflow to apply it properly  

Jake_Rosenfeld

@joerg_arnold

Because Onshape has multi-part part studios, Tim is suggesting that you just model the balks and the hip rafter in the same Part Studio, and use a subtraction.  Is there something specific that is causing you trouble?

Jake_Rosenfeld

Here is a quick example (feel free to look through the features by double clicking, or make a copy to get a more detailed view):
https://cad.onshape.com/documents/af9b1d618a95b109024e900b/w/0e40139928c46f072effaafe/e/d705bc705c632340ed711c72

Stefan_DMS

You may not even need the parts in the same part studios. You could use a "in context" edit. You do that by right-clicking on the part in the assembly, and select "edit in context". Then you may be able to do a boolean operation, otherwise, a sketch extrude will do the trick.

mahir

For now, I would avoid the in-context feature. That's more of a next level technique, and it would benefit you to first learn the basics of multi-body part studios.

joerg_arnold

Thanks to all for the answers!

@Jake_Rosenfeld :

I was able to replicate your example of subtracting to bodies by using the Boolean tool. Thanks!
Afterwards I tried to apply this to my project. I created a rectangular tool that i wanted to subtract from the target (which is the "hip rafter"). As i tried to apply the Boolean operation i couldn't select  the tool and the target as single parts. I just got one selectable unit out of both parts!
What did I wrong here?

my document url:
http://cad.onshape.com/documents/ac36b4c9dcb9af7d189aae9b/w/bcab52b58daa7cc952da01bc/e/a0f1b44723c7d0ef68900b58

owen_sparks

Ok, here is a copy of your file:-

https://cad.onshape.com/documents/ff6546867121648627049b8c/v/5f821257573d35ab3d0d5043/e/ebfd0e0949a6783a66fd8168 

You'll see I've:-

(1) Changed your extrude2 to "New" from "Add" so that it creates a separate part.

(2) Added a boolean feature to cut away the new part from the old part.  (I've added an offset to give a tolerance with the offset face option.)

Does that help?

Cheers, Owen S.

joerg_arnold

Yes, this solved my problem! Thanks for the excellent support!!

https://cad.onshape.com/documents/ac36b4c9dcb9af7d189aae9b/w/bcab52b58daa7cc952da01bc/e/a0f1b44723c7d0ef68900b58

owen_sparks

@joerg_arnold

Sure thing, it's like that here

Owen S.