Turbo Talk => Problems => Topic started by: NeverStop on December 17, 2018, 08:11:51 AM

Title: Solid Edit ? Best practice ? Any tips?
Post by: NeverStop on December 17, 2018, 08:11:51 AM
Folks,

The attached part I want to explode so I can alter some dimension and split in three parts for 3D print.
I have experimented with explode the part twice. But ends up with a lot of lines.
This is a imported step part and not drawn by myself.

Any suggest how I can do ?

Best regards
NeverStop

Title: Re: Solid Edit ? Best practice ? Any tips?
Post by: Andy H on December 17, 2018, 11:40:16 AM
The part is a single fully joined ACIS solid, therefore exploding from an ACIS produces a TC surface then polyines.  If the part was 3 separate parts grouped or a block, then exploding would separate.  Also if the single ACIS solid was Boolean added with gaps between the parts, then exploding would produce 3 ACIS solids.  But as a fully joined part it cannot be simply exploded.

You can use the 3D slice tool, see help file (https://turbocaddoc.atlassian.net/wiki/spaces/T2UG/pages/98926610/3D+Slice).  to cut the object into separate pieces.  the method would depend on how you want it slicing.  For Example.  To slice off the top overhang. Slice by 2 points works in front view. Slice by workplane requires a workplane setting up on the underside of the overhang.   Slice by facet works if on rotates the view so one can access the facet on the underside of the overhang.  Slice by plane (3 points) works in ISO view by snapping to 3 vertex points to create a sort of temporary workplane.

Title: Re: Solid Edit ? Best practice ? Any tips?
Post by: NeverStop on December 17, 2018, 12:23:06 PM
The part is a single fully joined ACIS solid, therefore exploding from an ACIS produces a TC surface then polyines.  If the part was 3 separate parts grouped or a block, then exploding would separate.  Also if the single ACIS solid was Boolean added with gaps between the parts, then exploding would produce 3 ACIS solids.  But as a fully joined part it cannot be simply exploded.

I suspected this, but I hoped it was some trick.

Quote
You can use the 3D slice tool, see help file (https://turbocaddoc.atlassian.net/wiki/spaces/T2UG/pages/98926610/3D+Slice).  to cut the object into separate pieces.  the method would depend on how you want it slicing.  For Example.  To slice off the top overhang. Slice by 2 points works in front view. Slice by workplane requires a workplane setting up on the underside of the overhang.   Slice by facet works if on rotates the view so one can access the facet on the underside of the overhang.  Slice by plane (3 points) works in ISO view by snapping to 3 vertex points to create a sort of temporary workplane.

I was thinking about slice tool, but I am afraid it would be difficult to slice the right place.
But I will do my best and play with it.

But after I explode the part completely. Will it be possible to create a solid of the part again ?

Thanks!

Best regards
NeverStop

Title: Re: Solid Edit ? Best practice ? Any tips?
Post by: Andy H on December 17, 2018, 01:13:51 PM
But after I explode the part completely. Will it be possible to create a solid of the part again ?

Theoretically, yes.   BUT, in practice, No worth the effort.  It would mean separating the sections (polylines), ansuring no polyline is missed.  Converting all the polylines to ACIS surfaces, then add the required ones together and then hoping it will convert to solid, all without errors creeping in. but the main problem is that curves would end up as flat rectangular or triangular facets, rather than smooth curves.  One can increase the ACIS facet setting before exploding to produce more polylines,  but the more exploded polylines it creates, the higher the risk of failure when trying to convert back to solid.

Definitely not worth the effort.  Attached is how bad the object looks after doing the above at the default ACIS setting, I tried at ACIS quality 90, but it failed to convert to solid - it threw up an error).
Title: Re: Solid Edit ? Best practice ? Any tips?
Post by: NeverStop on December 17, 2018, 01:26:05 PM
Quote
Theoretically, yes.   BUT, in practice, No worth the effort.

I undestand the road must be slicing ?

Best regards
NeverStop
Title: Re: Solid Edit ? Best practice ? Any tips?
Post by: Andy H on December 17, 2018, 01:53:02 PM
I undestand the road must be slicing ?

I have not much experience with other cad packages, so will have to leave it to others to comment really.  I suspect most lower priced CAD (as opposed to things like Solidworks), will operate in a similar manner.

Slicing is a good way to go, and is the method I use to split before 3D printing.

Another method I occasionally use if slicing cannot produce what I require, is to.  Draw a sacrificial box, cylinder or extruded polyline just around the part of the object I need to separate, 'Make copy' both the main part and the new object, so there are two of each.  3D boolean intersect one of the main parts with one of the new parts.  then subtract the remaining new part from the remaining main part. Thus leaving two separate parts.      This may sound complicated, but is quite fast once you have done it a couple of times.
Title: Re: Solid Edit ? Best practice ? Any tips?
Post by: Jeffin90620 on December 17, 2018, 04:38:56 PM