Countersink in sheet metal model

[wfaulk]

I created a model that's supposed to be for a sheet metal part. I created a 2D sketch that included some throughholes for screws. That is, the screw is intended to pass through the hole to thread into something on the other side of the sheet metal.

I took that sketch and padded it with the thickness of the sheet metal. I now want to apply a countersink for those holes. I select circle on the top face of the part and select the Hole toolbar icon. I select Profile to be "ISO metric regular profile", set the Size at M1.6, and set the hole depth to "Through all". And I'm not sure really what to do at this point.

I feel like selecting M1.6 should set the relevant dimensions, but it doesn't seem to. Or maybe it does and I'm not understanding properly. The countersink depth defaults to zero, which seems odd. It seems like it ought to default to the depth of the head on an M1.6 screw. But if I set it to that, it seems to work right, I think, but then I'm not sure what the countersink diameter means. If I set the countersink to be deeper, the diameter of the top of the countersink gets bigger, but the shown diameter stays the same. (Nevermind. I see now that the diameter changes with the depth.)

Also, if I mess around and set the screw type to M8, it completely overwhelms the sketch's hole, which is reasonable, but then when I set it back to M1.6, it doesn't make the hole smaller. In fact, if I ever make the countersink diameter bigger, I can never get it to be small again and I have to start over.

Also, if I select one hole, I have to click the "Reversed" checkbox, but if I select multiple holes, I don't.

I don't know if these are bugs or if I'm not understanding how it's supposed to work or what.

I can't attach a screen capture, so here's a link: https://i.imgur.com/uuLp7bu.mp4

File Attachment from a reply below

OS: macOS 10.16
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.24291 (Git)
Build type: Release
Branch: (HEAD detached at 0.19.2)
Hash: 7b5e18a0759de778b74d3a5c17eba9cb815035ac
Python version: 3.8.8
Qt version: 5.12.9
Coin version: 4.0.0
OCC version: 7.4.0
Locale: C/Default (C)

Edit: Updated to be more clear about what depths I'm talking about, and added a link to the file attachment.

[Willem]

The depth should be "Through all"
If that does not work upload your file so we can investigate it

Edit: Make 1 hole and copy that with multitransform/mirror to 4 holes

[wfaulk]

Thanks for the response.

Not the hole depth, the countersink depth. I'd set the hole depth to "Through all". I guess I failed to mention that.

I also meant to upload the file, but forgot when I had trouble with the screen capture. Attached now. I'm wanting to add the countersinks to the 12 small holes.

The attached file is before any attempt to apply countersinks.

I also meant to ask if this is what a sheet metal fabricator would want, or if I'm going about it the wrong way altogether.

[papyblaise]

in my opinion: drill the holes to the final diameter and make a chamfer once by selecting the edge of each hole

[wfaulk]

drill the holes to the final diameter

They're at final diameter in the sketch. Are you suggesting that I should use the hole tool to do it instead? If so, how do I place the holes?

make a chamfer

So, use the chamfer tool on the holes instead of using the countersink option of the hole tool?

[Shalmeneser]

The PartDesign_Hole doesn't care of original size of your hole (or of the sketch radius).
The countersink depth modify (badly) countersink diameter (bug !).

In your example, you need only to chamfer the holes as they are at the right dimension.

[chrisb]

Normally you would have a separate sketch for the PartDesign holes, where the positions are marked by circles or arcs of arbitrary diameter. The Hole feature takes only the centers, the diameters are defined in the Hole feature.