Does anyone here know how to slice a solid with a lofted surface. I have tried both with the loft as a surface and as a solid. The odd thing is that occasionally it will work (as a solid) then most often not.  What I am doing is using TC to design a boat hull. I can get good hull surfaces but need the hull to slice solids to create frames and bulkheads
Any help is appreciated
Cheers
Michael C 

Which version are you using?

The usual reason for failure is that the surface must overlap the solid, ie if you subtract the solid from the surface, it must leave the complete perimeter edge of the surface with no gaps. 

Examples of slicing using an ACIS surface (not a TC surface).  Blue is the boat hull surface, Black are solid boxes.

I am using TC 2017 with Windows 10.   I will send some images tomorrow  to show what I am attempting to do and ain't working
Thanks
M

The loft profiles must be open.

Henry H

I send a simple example.  What I need to do is have the lofted part slice or subtract the beam such that part of the beam (outside the hull) can be deleted leaving the portion inside the hull in place. This is essential in boat design.  In the file I send both parts are solids.

It'll work if you turn the Part Tree off. Go to Options>ACIS and UNcheck "Create Editing History."

Henry H

Nope.  There is no way that I can get the lofted part to dissect the beam. A solid can be created at the intersection but this will not function as a slicing or subtraction part either  The program keeps saying the parts don't intersect. It can all be done through exploding the beam but this is far too tedious an one does not end up with a solid beam

The frustrating thing is that it HAS worked on a few rare occasions. It has to be associated with the  properties of the lofted part.

Thanks for all your suggestions.

M

Hi Michael,

for me, the slice tool only works reliably when surfaces are derived from 2D profiles.  Your curved surface is probably compound.

Notwithstanding that, this is what I did:

1.  Turn off the part tree.

2.  Explode each object, so they are both ACIS solids.

3.  Give some thickness to the curved object, say 0.01 mm, using the shell tool.

4.  Boolean subtract the curved object from the beam, remembering to select "Don't remove the subtrahend" if you wish to retain this part.

5.  Select the beam and explode once, to create two separate ACIS solids.

Regards Tim

Worked Ok for me in 2017 pro using Henry's suggestion.  I opened the drawing, turned off create edit history, slice by surface worked fine. 

That said, just in case your loft is retaining some old history internally, One can, After turning off history, explode the loft once. It should then show in the selection palette as an ACIS object.  This will sever all ties to any 2D profile and wipe out any history.

Nope.  There is no way that I can get the lofted part to dissect the beam. A solid can be created at the intersection but this will not function as a slicing or subtraction part either  The program keeps saying the parts don't intersect. It can all be done through exploding the beam but this is far too tedious an one does not end up with a solid beam

The frustrating thing is that it HAS worked on a few rare occasions. It has to be associated with the  properties of the lofted part.

Thanks for all your suggestions.

M

Works for me in your drawing, every time. I turn the Part Tree OFF; activate the 3D Slice tool and enable "Slice by Surface"; click the box object; click the loft object. I'm using v2017.5, 32-bit with Windows 10 Pro. (Your drawing behaves exactly the same in my v2018.0, 64-bit.)

Henry H

Michael.  Just to add something else you could try.   In case for some reason TC is getting confused by the object axes (I've had this in the past).

Turn off History.  On the world workplane draw a large box so it full covers the loft,  3D intersect by clicking the box and then the loft, this will (should) reset the object axes, (which will actually now be wrong but it shouldn't matter).  try slice by surface and see what happens.   

Hi Andy and others

Mine is working now.  I turned off Part Tree yesterday and got no improvement but today we are away.

Lots of good advice here. Thanks folks. Now I can draw me a boat. I will have more questions to ask about getting accuracy in the lofted part down the track, That can wait for now

Cheers

Michael C   

Hi Andy and others

Mine is working now.  I turned off Part Tree yesterday and got no improvement but today we are away.

Lots of good advice here. Thanks folks. Now I can draw me a boat. I will have more questions to ask about getting accuracy in the lofted part down the track, That can wait for now

Cheers

Michael C

Please report this to iMSI,
It appears that the Part tree is dysfunctional. If this is as designed there should be a warning 
Turning it Off allowed the slice by surface.
I tried Andy's method with part tree ON and the slice still failed.

For Me.  There is something strange about how TC (and possibly part tree) is coping with the axes.

Just gave it another go.  With part tree turned On.   If I draw a box on the world workplane (I drew it slightly larger than the existing one).  and try the slice, it fails. But. If I then intersect the new box with the existing box, it slices OK. 

If I use my own template, and draw a box and loft two splines,  as I would normally do the it (draw box on world workplane, splines in front view, then loft)  it slices Ok every time without fail. 

However.  Again in my own template.  If I recreate the loft and box, using the exact same axes alignment as the original file.  It fails to slice.

I guess the moral is. If it fails first time, try a few different methods until one works. 

 

Michael.  Just to add something else you could try.   In case for some reason TC is getting confused by the object axes (I've had this in the past).

Turn off History.  On the world workplane draw a large box so it full covers the loft,  3D intersect by clicking the box and then the loft, this will (should) reset the object axes, (which will actually now be wrong but it shouldn't matter).  try slice by surface and see what happens.   

I was having trouble again this morning. I tried the above and it worked. Thanks Andy

Cheers
M

I had some sporadic failures in the last couple days, even when creating the Solid Surface from a 2D object using the Loft command.

It is less likely to fail using a Spline as the source for the Solid Surface.  Somewhat more likely to fail with a Polyline that has curves in it (haven't really run this down).  I don't use Beziers because, for some reason, I seem to recall reading that they were more likely to fail, but I just ran an experiment on a moderately complex object and it worked fine.

A straight line seems least likely to fail, but when it does, moving one of the end points slightly can help.


Jeff