Screw thread problem.

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 From:  -ash-
1669.1 
Hi all,

I'm trying to create a screw thread as shown in this thread:

http://moi3d.com/forum/messages.php?webtag=MOI&msg=767.1&highlight=yes

I create a helix then add a small triangle.




But when I sweep the triangle using the helix as the rail with a flat twist; I get this.





I tried the same thing in a new file and it worked ok. A bug maybe? Something I've done?

I've attached the offending .3dm file.

Regards
Tony


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 From:  Michael Gibson
1669.2 In reply to 1669.1 
Hi Tony, it is a bug, it happens specifically if you have a helix with 7 twists in it.

It happens that the sweep tests at 7 spots along the surface to see if the generated surface is coincident with the sweep profile at that spot, to see whether it needs further refinement or not. It so happens that the flat surface you show there actually meets that testing.

Please see this thread: http://moi3d.com/forum/index.php?webtag=MOI&msg=1263.1
for a workaround.

- Michael
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 From:  Michael Gibson
1669.3 In reply to 1669.2 
Or sorry - it is actually a 6 revolution helix that has the problem, that happens to have the exact arrangement at 7 spots along it which fools it into thinking that flat thing is ok.

But still that link shows how you can get it done by positioning the profile at a slightly different spot for this particular thing.

- Michael
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 From:  -ash-
1669.4 
Thanks, that explains it ;-)

Is there a list of these known bugs that I should have checked?

Regards
Tony

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 From:  Michael Gibson
1669.5 In reply to 1669.4 
Hi Tony, no not really, this is on my list of things that I've got here to fix up but I don't have that list set up on the web right now.

- Michael
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 From:  -ash-
1669.6 
No problem - just wanted to make sure I wasn't taking you away from V2 when I didn't need to :-)

Regards
Tony

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 From:  bothamjohn51@yahoo.com (BOTHAM)
1669.7 
Hay me botham and going to visit this site first time.

EDITED: 25 Jun 2010 by BOTHAM

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 From:  DannyT (DANTAS)
1669.8 In reply to 1669.7 
Hey bothem and welcome!.........um, but what are you doing in this thread ? you could just start a new thread introducing yourself that would be ok too!

Cheers
~Danny~
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