Editing a MESH (solid)

[LS120nz]

i hope you can help me out again this time... i have an stl i need to edit i have followed the wiki on in-porting it and making it a solid. i made a sphere that i want to remove from it but it wont let me.. i have tried subtractive sphere but it wants a body.. do i need to make one ??

the file is on my onedrive as too big for here..

https://1drv.ms/u/s!ArhzNv3jjwuggwKyXVq ... A?e=kUsRNL

thanks for any help

OS: Windows 10 (10.0)
Word size of OS: 64-bit
Word size of FreeCAD: 64-bit
Version: 0.19.22319 (Git)
Build type: Release
Branch: master
Hash: 33ef4e0e35fba74c6e2fa3829cfd15c4b6f67e94
Python version: 3.6.8
Qt version: 5.12.1
Coin version: 4.0.0a
OCC version: 7.3.0
Locale: English/New Zealand (en_NZ)

[heda]

have not looked at the file, and not entirely clear on starting point and what you really want to do.
in any case, just wondering if you really need a solid.

you have a stl that you want to edit by cutting with a sphere?
you can do that as well as a mesh and don't have to go via a solid. but you do need to install OpenSCAD as it's own program to do it (mentioned in the wiki), but you never have to open that program, fc uses it under the hood.

just a small showcase done in Mesh Design wb.

full.png (26.62 KiB) Viewed 1934 times

• created the cube and sphere with menu/regular solid (for you it is importing one and creating the sphere)
• moved the sphere to wanted location relative to cube
• made the cut with menu/boolean/difference, the result is the 2nd picture

This works well if you only need to edit the stl and the further use is also stl.
If you actually want solids because the further use is requiring solid, yes then you have to make solids - if it was me I would use the part wb (and not part design wb). When actually wanting to work in solids, having a complicated stl to begin with is not the best of starting points.

I guess there are other ways to do it as well, but that I will leave up to others to share.

[LS120nz]

thanks for the info.. and yes i only want to remove the sphere from the other stl..

[LS120nz]

i'm still totally lost in what/how to do what i need.. i just don't know enough about freecad..

anyone willing to help me / show me how to do it as i may have others i need to do it too..

thanks for any help

[heda]

can you reproduce the pictures in my earlier post?
no harm in making sure that the easy cases work for you before going into possible complicated ones.
I suggest to start there, if you get that working you might already know enough to sort things out by yourself.
the wiki should be enough to pull that off
just for the fun of it you could do it in both "mesh" and "solid" version.

the better (in fc-specific and general cad lingo) you can describe your own problem the quicker and better help you will get back.
in the simple case we are talking about a dozen mouse-clicks to get it done, so it should be possible to sort it out for anyone with some guidance.

[miniellipse]

If this is just a simple in-exact operation that you want to do....just do it in Tinkercad. It is an online application offered free by Autocad. It is extremely good at editing uploaded stl files. Upload your stl file, then create a subtractive sphere. Position this sphere and then Group the two items together. The group operation will perform the Boolean operation. You now export the new stl file out of the program.

[heda]

so, what you are saying is that regardless of program (or service) used the principal workflow is the same?

btw, the title of this topic should really be how to edit meshes, since stl's will never be "solids" in the cad world, sure they can be watertight volumes, but never solids from the cad-kernels perspective.

[LS120nz]

hi Heda fixed the heading... as i said i'm not the up with this jargon... i think i do still have tinker kad.. will check..

thanks

[LS120nz]

thanks for the heads up about tinker cad.. it worked great... just had to remember how to more around in it... but all done now... thanks again..

the next problem i have now is tinker cad says the mesh has over the allotted splines.. allowed in tinkercad. and in need to simplify the mesh ??? how do i do this..

thanks

[heda]

I know nothing about tcad, but just wondering if you indeed have realized that fc allows you to do the same with openscad installed (with no limitations in "alloted splines")?

and no worries on the solid / mesh story - the lingo can be confusing at times, thumbs up for the title edit!