topic Re: Best Practice for subtracting a solid part from a solid part in Inventor Forum

Best Practice for subtracting a solid part from a solid part

RunningMan0505 — Thu, 28 Oct 2021 12:07:33 GMT

What method do you like best for subtracting a solid volume from another solid volume. The basics of subtracting a smaller box from a larger box, but the end goal will be subtracting a complex part from a larger box.

thanks,

bryan

Re: Best Practice for subtracting a solid part from a solid part

SharkDesign — Thu, 28 Oct 2021 12:16:22 GMT

Combine and copy object are the best two.

Re: Best Practice for subtracting a solid part from a solid part

SharkDesign — Thu, 28 Oct 2021 12:17:37 GMT

This video is the way I've always done it.

If you just want to cut it out of a block you can skip the copy object part and just draw an extrusion as 'new solid' in the complicated part and use combine.

https://youtu.be/dvrMA15pj2o

Re: Best Practice for subtracting a solid part from a solid part

Gabriel_Watson — Thu, 28 Oct 2021 12:35:28 GMT

Here's the best method we use:
1) Save the initial part with a different name, as a new file.
2) Use extrusions or surface patches to cap/close any holes that are terminations of the path to be extracted.
3) Use the “Copy Object” tool (under Modify) and pick the main solid body only, select the option to create a new Composite, and leave the “Delete Original” selection off.
4) Right-click the main solid (under “Solid Bodies” in the Browser) and remove its visibility;
5) Under surface tools, now pick the “Sculpt” function and use the “Add” function, then select both the Composite of the main body and all caps/lids placed on step 2;
6) Click any green arrows to point towards the center of the path/objects, and select the “New solid” option for the Sculpt tool results, then hit OK;
7) Select the new (cavity) body and again choose to Modify > Copy Object, but this time select the option to create a new Repaired Geometry;
8 ) With the new geometry made, delete all other features in the browser for the part that are not the newly created Repaired Geometry.

Video of a small sample:

https://knowledge.autodesk.com/support/inventor-products/getting-started/caas/screencast/Main/Details/4007ca67-43e2-420c-8638-efbeda6ac43c.html

Re: Best Practice for subtracting a solid part from a solid part

JDMather — Thu, 28 Oct 2021 12:38:42 GMT

@RunningMan0505 wrote:

What method do you like best for subtracting a solid volume from another solid volume.

Depends.

I would not try to answer this question without dataset - or at least pictures.

There are many ways and many variables involve in the decision of technique that I would use.

Re: Best Practice for subtracting a solid part from a solid part

RunningMan0505 — Wed, 03 Nov 2021 10:42:42 GMT

Thanks all. So the combine method worked great was 2 generic solids I had created.

the fracture I am working with is a much more complex feature. After scrubbing it and reducing the faces in 3ds max I brought it into Fusion 360 and converted the mesh and exported as an Autodesk Inventor part (ipt). The file size is much more manageable and I am able to grab onto the part and work with it in Inventor.

When I try to use the combine method with this more complex part here is what happens:

Everything up to subtracting the part from the solid block volume performs correctly. When I try to subtract the complex part from the solid block it removes the internal volume of the solid block instead and leaves the complex part there. I thought maybe the part is still too complex for inventor to perform that operation?

Re: Best Practice for subtracting a solid part from a solid part

SharkDesign — Wed, 03 Nov 2021 12:47:32 GMT

Please provide images at least.

Re: Best Practice for subtracting a solid part from a solid part

JDMather — Wed, 03 Nov 2021 12:50:09 GMT

@RunningMan0505 wrote:

I thought maybe the part is still too complex for inventor to perform that operation?

Unfortunately no actionable information.

Re: Best Practice for subtracting a solid part from a solid part

RunningMan0505 — Wed, 03 Nov 2021 12:57:25 GMT

This is also my thoughts. there are still ~7000 faces and the file once it is converted to an (ipt) is still ~14,000kb.

Re: Best Practice for subtracting a solid part from a solid part

johnsonshiue — Wed, 03 Nov 2021 20:37:10 GMT

Hi! If the part was a scanned part or converted from mesh, I don't think you will get far in Inventor. Inventor's mesh modeling ability is very limited. Mesh is used as a reference to create precise geometry or drawing views.

I suggest you look into Fusion 360, which has a dedicated mesh modeling environment. You may be able to convert the mesh to a smoother Brep precise body.

Many thanks!

Re: Best Practice for subtracting a solid part from a solid part

RunningMan0505 — Thu, 04 Nov 2021 10:56:29 GMT

Thank you! I'm new to posting in any kind of forum and embarrassingly admit I tend to bounce around with my thoughts and leave out important details.

This was a CT scan originally and I eventually converted the mesh into Fusion 360. It sounds like I am using the wrong tool for the job (Inventor).

Is there a work flow for subtracting a solid volume from another solid in Fusion 360?

thanks again.

Re: Best Practice for subtracting a solid part from a solid part

RunningMan0505 — Thu, 04 Nov 2021 12:29:53 GMT

So this actually worked. I was able to create a solid rectangular volume around the converted mesh then use the Combine tool and it cut the fracture away from the solid volume. I now need to split this in half and this is where I'm running into errors again.

"No intersection between target and split tool"

I tried two methods so far:

Split Body: and created a plane where I needed to split it.

New Sketch: Create a new sketch on a plane where I need to split, then try to cut half of the solid away and save this down then go back and do the other half.

let me know if I need to be more clear.

thanks!

Re: Best Practice for subtracting a solid part from a solid part

johnsonshiue — Thu, 04 Nov 2021 19:10:53 GMT

Hi! Is this in Inventor or Fusion 360?

Many thanks!

Re: Best Practice for subtracting a solid part from a solid part

RunningMan0505 — Mon, 08 Nov 2021 12:41:35 GMT

I exported it to Inventor, but am thinking I should just forget trying to bring it into inventor and work directly in Fusion 360.

Any suggestions?

Re: Best Practice for subtracting a solid part from a solid part

johnsonshiue — Mon, 08 Nov 2021 20:12:07 GMT

Hi! For this particular workflow, I would do it on Fusion.

Many thanks!