radial holes on cylinder wall

[MikeDewitt]

Hi, I have a thick walled vertical pipe and I need two small radial holes down from the top and 30-degrees spread radially or lattererally. Neither hole is on a radial X/Y/Z axis of the Sketch.

I tried using a Subtractive Cylinder but when I get it out to the wall in the Z-direction (-70.0), I can't get it to rotate on the pipe center line, it wants to rotate from the outer-end of the Subtractive Cylinder and thus, no longer radial.

I searched here and youtube and only found one post from 2013 using a square block first, but Subtractive was not an option then.

How do I do this?

Thanks (if we are still talking)

OS: Linux Mint 20 (X-Cinnamon/cinnamon)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.21654 (Git) AppImage
Build type: Release
Branch: master
Python version: 3.8.2
Qt version: 5.12.5
Coin version: 4.0.0
OCC version: 7.4.0
Locale: English/United States (en_US)

[Roy_043]

You lost me at the first sentence.
In my mind you are talking about 3 distinctly different things:

1. Hole down from the top (I would say that a pipe already has a hole there...)
2. Radial hole
3. Hole not radial to center

Please post a file or a sketch.

[MikeDewitt]

Please post a file or a sketch.

I realized it needed some thinking through and was off getting a sketch, but then Bluetooth on the phone wouldn't work -- blah blah blah.

Anyway, here it is.

holes.jpg (15.42 KiB) Viewed 1736 times

[fosselius]

create a plane and set it to correct angle then put your sketch on the plane.

you could also just create the sketch at xz plane and then rotate the sketch before doing your pocket.

here is a short video on creating planes
https://youtu.be/WdBQPXeAeMc

[MikeDewitt]

[*]Hole down from the top (I would say that a pipe already has a hole there...)

Please quote me correctly. I wrote "holeS down ..." and no pipe I know has 2-holes down from the top.

[MikeDewitt]

create a plane and set it to correct angle then put your sketch on the plane.

Thanks, but this would seem a prefect use of the Subtractive Cylinder if I can be shown how to rotate from the pipe's vertical center line and not the end of the Subtractive Cylinder. It is sittng there so close.

[papyblaise]

Do additif cylinder , zen an soustractive cylinder
select a vertical plane in sketcher and do a cercle , do pocket thrue all
select polar array , do 2copy at 30°

[TheMarkster]

You could attach the subtractive cylinder to one of the circles on the top face of the pipe, and then adjust the rotation to 90 degrees about x or y. For the 2nd cylinder do the same and add another 30 degree rotation about z.

Snip macro screenshot-810281.png (139.19 KiB) Viewed 1710 times

Snip macro screenshot-c64aa4.png (131.33 KiB) Viewed 1710 times

Snip macro screenshot-51c4eb.png (134.69 KiB) Viewed 1710 times

But this will leave you vulnerable to topological naming issue if you later change the sketch that defines the pipe in such a way that the edge you attached to gets renumbered.

[fosselius]

made a new video where i show step for step:

https://youtu.be/l1aMGl37OiQ

[MikeDewitt]

Wow, thanks guys.

I will try all three and see which method seems the more simple to me.

#fosselius: You went to quite a lot of trouble and I appreciate that. Thank you.