Help creating spheres on a face.

Post here for help on using FreeCAD's graphical user interface (GUI).
Forum rules
and Helpful information
IMPORTANT: Please click here and read this first, before asking for help

Also, be nice to others! Read the FreeCAD code of conduct!
sdooweloc
Posts: 16
Joined: Thu Dec 01, 2022 4:42 pm

Help creating spheres on a face.

Post by sdooweloc »

Hello all. Trying to figure out how to do something. These bars I want to put semi-spheres on the ends of to basically round them out to meet the top face. I cannot figure out how to do so though. I tried sketching an arc and revolving it but I either get nothing, weird coning, or a loop the size of my whole part lol. I also tried adding a sphere from the Part Design workbench but it either didnt do anything or did the weird cone thing to the pipe too. Any advice is appreciated.

For reference I am basically working to duplicate the attached openSCAD project in FreeCAD

Code: Select all

OS: Arch Linux (KDE/plasma)
Word size of FreeCAD: 64-bit
Version: 0.21.0.31642 (Git)
Build type: None
Branch: master
Hash: 6cf62992548132c2fc4cae86024e411f35c36618
Python 3.10.9, Qt 5.15.8, Coin 4.0.1, Vtk 9.1.0, OCC 7.6.3
Locale: English/United States (en_US)
Attachments
Floss_bow_labeled.scad
(3.93 KiB) Downloaded 8 times
FlossBowLabeled.FCStd
(300.6 KiB) Downloaded 10 times
Bance
Veteran
Posts: 4190
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Help creating spheres on a face.

Post by Bance »

The model is suffering from TNP.

I have placed all sketches on Std Planes and reversed some pockets, I also added construction lines in the 'spherical end sketch' to make the rotation and mirror/multi-transform easier.

You went about it a long way around, most of the mirrors could be done at once.
Attachments
FlossBowLabeledBance.FCStd
(295.3 KiB) Downloaded 7 times
sdooweloc
Posts: 16
Joined: Thu Dec 01, 2022 4:42 pm

Re: Help creating spheres on a face.

Post by sdooweloc »

Thank you. Yeah I am still very new to CAD in general and very new to FreeCAD so dont really know the "right" ways to do things like those and so was just doing things as I found they worked haha.

So just so I know for learning do you know what I may have been doing wrong when trying to make my spherical ends that you didnt do wrong? Or is TNP just one of those things that kinda is going to come up a lot?
sdooweloc
Posts: 16
Joined: Thu Dec 01, 2022 4:42 pm

Re: Help creating spheres on a face.

Post by sdooweloc »

Bance wrote: Sat Jan 28, 2023 1:36 pm The model is suffering from TNP.

I have placed all sketches on Std Planes and reversed some pockets, I also added construction lines in the 'spherical end sketch' to make the rotation and mirror/multi-transform easier.

You went about it a long way around, most of the mirrors could be done at once.
Oh wait nevermind I think I see what you did. Instead of mapping the sketch to the face at the end of the pipes you mapped the sketch to the XZ plane and then offset the Z by the length parameter of the pipes so it is placed right but only supported by the global XZ plane and thus not dependent on other faces or lines names as it exists on its own.
Bance
Veteran
Posts: 4190
Joined: Wed Feb 11, 2015 3:00 pm
Location: London

Re: Help creating spheres on a face.

Post by Bance »

Exactly, if the sketch depends on Generated(solid) geometry it will get mis-placed, because the model (solid) has its edges renamed.

To avoid this use other sketches or Std planes and offsets.
sdooweloc
Posts: 16
Joined: Thu Dec 01, 2022 4:42 pm

Re: Help creating spheres on a face.

Post by sdooweloc »

Gotcha gotcha. I will try to remember that. That does make sense. Because by definition the global planes are constants and if you stack everything against that constant there shouldnt be problems but what I was doing was basically took a variable based off that constant and tried to stack another variable on top of it and the middle variable changed and broke everything after it.

Definitely good to know and something to try to remember and learn haha. CAD as a whole is a lot to take in and the fact that FreeCAD has so many fewer videos and such on it than the "popular" programs doesnt help with that learning curve. So I very much appreciate your willingness to help and the responsiveness of the forums.

Now just have to place some text and I am off to the races haha.
User avatar
papyblaise
Veteran
Posts: 7877
Joined: Thu Jun 13, 2019 4:28 pm
Location: France

Re: Help creating spheres on a face.

Post by papyblaise »

the easiest way is to make a fillet 0.01mm smaller at each end, and do "Refine = true" to remove the connection lines between each Pad
Attachments
levier.JPG
levier.JPG (27.94 KiB) Viewed 532 times
sdooweloc
Posts: 16
Joined: Thu Dec 01, 2022 4:42 pm

Re: Help creating spheres on a face.

Post by sdooweloc »

papyblaise wrote: Sat Jan 28, 2023 3:26 pm the easiest way is to make a fillet 0.01mm smaller at each end, and do "Refine = true" to remove the connection lines between each Pad
Is there anything wrong with having the connection lines between the pad? I personally dont really mind them especially since they help sanity check my values and positions are all where I expect them to be.
drmacro
Veteran
Posts: 8872
Joined: Sun Mar 02, 2014 4:35 pm

Re: Help creating spheres on a face.

Post by drmacro »

sdooweloc wrote: Sat Jan 28, 2023 3:29 pm
papyblaise wrote: Sat Jan 28, 2023 3:26 pm the easiest way is to make a fillet 0.01mm smaller at each end, and do "Refine = true" to remove the connection lines between each Pad
Is there anything wrong with having the connection lines between the pad? I personally dont really mind them especially since they help sanity check my values and positions are all where I expect them to be.
They are mostly cosmetic, so not a problem to leave them.

Sometimes Refine = true can help with fillets/chamfers, But, they can also cause problems that are hard to troubleshoot. So, if they don't bother you, just leave them.
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
User avatar
Shalmeneser
Veteran
Posts: 9475
Joined: Wed Dec 23, 2020 12:04 am
Location: Fr

Re: Help creating spheres on a face.

Post by Shalmeneser »

:idea:
Attachments
FlossBowLabeled_SHALM.FCStd
(205.14 KiB) Downloaded 8 times
Capture du 2023-01-28 17-38-21.png
Capture du 2023-01-28 17-38-21.png (32.35 KiB) Viewed 429 times
Post Reply