overlapping pads in PartDesign don't fuse/unite

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dbotos
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Joined: Sat Nov 26, 2022 3:51 pm

overlapping pads in PartDesign don't fuse/unite

Post by dbotos »

Longtime SolidWorks and NX user here trying to learn FreeCAD.

I sketched an X shape and padded that to the desired thickness. Then I sketched some tabs sticking off of the ends of the X and padded that sketch back down to the bottom face of the X shape. Instead of getting one nice-looking solid, the graphics window looks like it has 5 different solids, including showing the overlap between bodies. But if I click on the body, it gives me a transparent rendering of what I was expecting.

overlapping_pads_in_freecad.png
overlapping_pads_in_freecad.png (27.66 KiB) Viewed 637 times
overlapping_pads_in_freecad_body_selected.png
overlapping_pads_in_freecad_body_selected.png (37.3 KiB) Viewed 637 times

The boolean tools in FreeCAD appear to be just for working with distinct bodies, but what I've got are pads within the same body. Is there some way to get it to fuse or unite overlapping pads or should I have made the tabs as a new body (which would potentially give the error about making separate solids)?

Thanks,
David
Last edited by dbotos on Sat Nov 26, 2022 10:56 pm, edited 1 time in total.
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NewJoker
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Re: overlapping pads in PartDesign don't fuse/unite

Post by NewJoker »

Use the Refine option in Pad settings instead of boolean union.
chrisb
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Re: overlapping pads in PartDesign don't fuse/unite

Post by chrisb »

Hi and welcome to the forum!

Don't worry, they are fused. PartDesign applys the boolean union all by itself. Only the seams remain. You can remove these too by setting Refine=true in the last feature. I don't recommend to do this by default, because in the rare occasions when it fails, there is no obvious connection to the refine causing it.
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Shalmeneser
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Re: overlapping pads in PartDesign don't fuse/unite

Post by Shalmeneser »

File ?
Attachments
X_file_SHALM.FCStd
(32.4 KiB) Downloaded 10 times
Capture du 2022-11-26 22-31-00.png
Capture du 2022-11-26 22-31-00.png (23.29 KiB) Viewed 585 times
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dbotos
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Re: overlapping pads in PartDesign don't fuse/unite

Post by dbotos »

Ah, thanks all - that did the trick:

overlapping_pads_in_freecad_fixed.png
overlapping_pads_in_freecad_fixed.png (31.01 KiB) Viewed 556 times

Here's the completed model. It's a minimalistic mount for an Arduino Uno r3. It connects the mounting holes for the board (the pattern of which they didn't make symmetric in either X or Y) with an X shape, provides some little bosses for the board to sit up on, and then brings tabs out past the edges of the board so you can install or remove the mount without having to take the board off:

uno_X_mount_freecad.png
uno_X_mount_freecad.png (26.17 KiB) Viewed 556 times

Part file attached. Holes through the standoffs are the tap drill size for 4-40 and holes through the tabs are clearance for 4-40.
Attachments
uno_r3_mount_X.FCStd
(113.6 KiB) Downloaded 10 times
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Shalmeneser
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Re: overlapping pads in PartDesign don't fuse/unite

Post by Shalmeneser »

tabs_sketch has a problem (and we can see modifications donwstream) !

You should use simple slots in this sketch (as in my file).

I woud do :
1) one sketch for the 4 circles for arduino holes.
2) one sketch for one X line = slot + external geometry
Pad this sketch
3) one sketch for other X line = " + "
Pad this sketch
4) one sketch for extension = slot + external geometry
Pad this sketch
5) one sketch for higher holes = external geometry
Pad this sketch

So you just need slots or circles in your sketches.
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