FreeCAD: A moderately complex example

Home Model Engine Machinist Forum

Help Support Home Model Engine Machinist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
"Try out your method and report back on how it worked." : Krypto: I did just that in post #3).

Oh, I was expecting to see a file as it's easier to follow the logic that way. Can you zip up and post the Freecad file? You can't post the raw Freecad files here, but it works fine in an archive.
 
Fillets are what I have the most problems with in 3D modeling.

I guess the program is trying to patch together different surfaces, and arrive at some standard geometric shape.

Fillets generally work well for simple shapes.

For shapes with compound curves and lots of complexity, the software (Solidworks in my case) sometimes struggles.

When I started using 3D modeling software, I assumed that everything would be cut-and-dried (so to speak) like 2D Autocad, ie: everything was clean and precise.

3D modeling can evolve into a lot of approximates, such as with complex fillets, and I have had to get use to that mindset.

.
 
@johnmcc69 I get your point for sure. I'm always looking for the most efficient route, which yours was, and there's affordable options out there. Some of us delve in the dark side of CAD maybe for supporting engineering work or for solving puzzles.

Fillets are what I have the most problems with in 3D modeling.

I guess the program is trying to patch together different surfaces, and arrive at some standard geometric shape.

Fillets generally work well for simple shapes.

For shapes with compound curves and lots of complexity, the software (Solidworks in my case) sometimes struggles.

When I started using 3D modeling software, I assumed that everything would be cut-and-dried (so to speak) like 2D Autocad, ie: everything was clean and precise.

3D modeling can evolve into a lot of approximates, such as with complex fillets, and I have had to get use to that mindset.

.
Regarding the impeller fillets, here's a quick buttery demo in Plasticity (hopefully it loads). It had the ability to import the dumb solid step file I created, remove fillets, and do what I'm showing below.

Parasolid.gif
 
Oh, I was expecting to see a file as it's easier to follow the logic that way. Can you zip up and post the Freecad file? You can't post the raw Freecad files here, but it works fine in an archive.

Krypto, I wasn't sure if you were asking me or John, but attached is the "simple approach" that I first took for the impeller.
 

Attachments

  • impeller.zip
    921.4 KB · Views: 2
Everyone struggles with fillet and no cad program has a great solution. (ProE, UG, Creo, Solid Works, etc.) The order is very very important. And you can not make a filet that goes over another larger often. Do not have to be much smaller. Seem the video shows your not doing bad at all. I have had in the last few models I built go back to sketches and change the order. Fillets in general should be the finishing touches of a model, but that doesn't always work. I wish there was some trick that I found. Now I am an engineer that has done a lot of 3D modeling but am not a cad designer that spends all day modeling. They do have tricks or approaches that have been learned through much effort.
 
@johnmcc69 I get your point for sure. I'm always looking for the most efficient route, which yours was, and there's affordable options out there. Some of us delve in the dark side of CAD maybe for supporting engineering work or for solving puzzles.


Regarding the impeller fillets, here's a quick buttery demo in Plasticity (hopefully it loads). It had the ability to import the dumb solid step file I created, remove fillets, and do what I'm showing below.

View attachment 145315

Zeb, that is super cool. Is Plasticity more like Blender, or more of a 3d CAD like Solid Works or Fusion 360 or so on?
 
Zeb, that is super cool. Is Plasticity more like Blender, or more of a 3d CAD like Solid Works or Fusion 360 or so on?
Plasticity is marketed as CAD for artists. Similar to MOI/Rhino, but running on Parasolid kernel (NX, Solidworks) and a super smooth, modern UI. At $100 for the indie version, it is a screaming deal for a Parasolid port and you own the tool. He basically isn't making any money on the indie version, since a lot of that goes to porting Parasolid like other companies do.

Like Rhino, the biggest difference with standard CAD is there's no history timeline and no constraints on sketches. Angles and dimensions can all be entered, so you can be as accurate as you want. I create a folder named "Sketches" that I drag/drop items into and rebuild surfaces and solids out of it. Similar to Rhino except more intuitive for managing construction geometry. That might be a turn off for many here, but it's just a different way to model. No sketch constraints also brings a performance increase. I like to think of it as drafting on paper and using applied geometry.

If you have old STEP dumb solids from a CAD product you no longer have access to, you can re-dimension G1 fillets, faces, etc. Very similar to synchronous modeling in NX. If there's a face you want to move or a drilled hole you want to size, you click it and type in the value. A (G1 conic) fillet chain can be clicked and removed, then reapplied. It even has an experimental tool that auto removes fillets by size entered. etc. Some might stress about not having a rebuild history, but when there's no history to rebuild, things don't break as often.

I could go on, but maybe discussion for another thread for sure. Here's a doodle I made yesterday and even though I struggled quite a bit trying different things in the recording, it took only 57 minutes to model. This is more a complement of the software.

Last word is that it won't do everything, but in my case it is a huge complement to Alibre for a NURBs modeling workflow. I can leave both on a machine in the attic for ten years, and if I have the itch it's easy to fire up and learn again.

Trackball1.PNGTrackballRender.png
 
I am curious to which rendering program did you use for the texture in the second drawing?
 
I looked on the Plasticity website (plasticity.xyz), and saw the pricing, but couldn't find any information about which platforms it will run on. I run Linux as my daily driver, so that may be a factor ...
 
I looked on the Plasticity website (plasticity.xyz), and saw the pricing, but couldn't find any information about which platforms it will run on. I run Linux as my daily driver, so that may be a factor ...
It doesn't appear that Linux will be officially supported in the near term, but there are a few users successfully porting it so far.
I am curious to which rendering program did you use for the texture in the second drawing?
-Render: Blender 3.4 Cycles
-Exr for lighting: Sunflower Sky, free from polyhaven,
-Realtime Materials addon for Blender
-DecalMachine addon (for dropping custom decals)

ScreenBlender.PNG
Edit* Added STEP file
 

Attachments

  • Trackball00.zip
    1.4 MB · Views: 7
Last edited:
It doesn't appear that Linux will be officially supported in the near term, but there are a few users successfully porting it so far.

-Render: Blender 3.4 Cycles
-Exr for lighting: Sunflower Sky, free from polyhaven,
-Realtime Materials addon for Blender
-DecalMachine addon (for dropping custom decals)

View attachment 145532
Edit* Added STEP file
I appreciate this Zeb! Inventor meets my needs, but I would like to play around with some different tools. These look like are a good place to start.
 
I appreciate this Zeb! Inventor meets my needs, but I would like to play around with some different tools. These look like are a good place to start.
Here's a Blender vanilla file that might save folks here some time. Instructions on the left column. Lots of tutorials if you get stuck.
 

Attachments

  • BlenderScene.zip
    124.8 KB · Views: 3
I downloaded the beta as Joe described. It runs ... but I'm not entirely sure how to make it do what I want it to. I imported a .STEP file containing the non-filleted impeller, and I can click on an edge and pull it to create a fillet - very cool - but I don't see a way to set a particular amount of fillet, and to replicate that on all the edges. That may just be the fact that I have barely started to play with it!
 
Might be worth opening a new thread. Step exporters will vary in quality, so hopefully everything stitches on import. The impeller should be under solids, if the STEP didn't stitch on export, it'll be a group of sheets. Here's a few things to try:
  • 1,2,3 &4 are selection types, fillets will work only under edge select (2). TAB allows all selections.
  • F brings up a search menu, you can right click searches and save as favorites in your search menu.
  • Shift+Select adds edges, Ctrl+Select subtracts. Alt+Select selects a chain or edge loop (seen below in the GIF). Searching "Remove Fillets From Shell" is worth experimenting with.
  • Pulling on the yellow widget after selection opens the fillet menu (shortcut B). Negative chamfers, positive fillets. You can type the value in the menu on the lower left.
fillets.gif
 
Here is a brief video demonstrating the results. I am very pleased - really good air flow, and with the hose on, not obnoxiously loud. (Some of the noise in the video is actually the cooler pump, not just the impeller.)

 
  • Like
Reactions: Zeb

Latest posts

Back
Top