Can't use pocket

[chhene]

So I have this part I have been working on, and I have arrived at a problem that I don't understand how to fix. Attached is a copy of the freecad file. The part is a rectangular piece with fins sticking out of it on either side. I wanted to cut off those fins so that they were flush to the rectangular piece like on the opposite side of the piece. So I clicked on one of the rectangular faces to select it, and with the Part Design chosen I then clicked on the "Map a sketch to a face" button. But it doesn't work. Instead a select a face button pops up. It doesn't seem to be recognizing that I want to sketch on the face that I selected. I was planning on sketching on one of the rectangles faces and use the "Create a pocket with a selected sketch" button to cut off the fins. Why isn't this working?

[renatorivo]

Do you want this?

tesla.png (8.17 KiB) Viewed 917 times

tesla2-renato.FCStd

(348.99 KiB) Downloaded 19 times

Renato

[chrisb]

So I clicked on one of the rectangular faces to select it, and with the Part Design chosen I then clicked on the "Map a sketch to a face" button. But it doesn't work. Instead a select a face button pops up. It doesn't seem to be recognizing that I want to sketch on the face that I selected. I was planning on sketching on one of the rectangles faces and use the "Create a pocket with a selected sketch" button to cut off the fins. Why isn't this working?

"Map a sketch to a face" maps an existing sketch to a face. You seem to want to "Create a new Sketch". If you have selected a face, that creates a new sketch attached to that face.

[Montoya88]

I'm looking to cut a semi-circle into a pipe I have tried selecting the face of the pipe even the "seam" and I still get this pop-up here's the snapshot.

I'll also include the file as well the sketch titled "half pipe" is the actual part so it is not the sketch use for the cut

[chrisb]

In FreeCAD 0.16 you can attach sketches to planar faces only. You may search the forum for "helper pad" (use the quotes for the search!) to see how to attach it at the end of your pipe. E.g. https://forum.freecadweb.org/viewtopic.php?f=3&t=3907

[Montoya88]

I've found this method by accident, I used the join walled objects option and selected "Cutout for Object"