Wed, 08/03/2011 - 13:58
Forums:
Hi
I tried to shell (add thickness) the following object (on Draw)
# make prism
polyline f 0 0 0 100 0 0 100 100 0 0 100 0 0 0 0
mkplane f f
prism p f 0 0 200
# make fillets
explode p e
blend b1 p 10 p_1 10 p_8
thickshell r b1 -20
No results, unless I apply offset value Is there a way to do that?
Please help
Davide
Wed, 08/03/2011 - 14:29
Davide,
In fact you met the same situation as before with fillets - filleted face disappear for the specified offset. It is a natural limitation. The last value of the offset (negative offset) which you may use for this case is => "-9.999".
Regards
Thu, 08/04/2011 - 12:47
Thanks Supervisor
I do not fully understand the link between this limitation on shelling and the limitation on filleting
Can you please explain?
Davide
Thu, 08/04/2011 - 13:05
with a certain radius, the faces you started the fillet from will simply dissapear, since the surface will be consumed by the fillets.
Fri, 08/05/2011 - 17:45
Hi
unfortunately I still do not understand the link between filleting and your comment
in filleting, it looks like that faces cannot be "fully consumed"
in shelling, I have problems also without fillets.
See below, a solid with a single chamfer made with Draw
# make prism
polyline f 0 0 0 100 0 0 100 100 0 0 100 0 0 0 0
mkplane f f
prism p f 0 0 200
# make chamfer
explode p e
renamevar p_1 pe_1
explode p f
chamf ch p pe_1 p_1 S 20
axo
fit
# shelling
donly ch
thickshell ts ch -35
---
notice the value "-35".
---
Supervisor?
Davide
Fri, 08/05/2011 - 18:54
Dear Davide,
If you will analyze the case more carefully you may find
that starting from some predefined for this case offset value (34.1..)
the internal shell (result of offset of the initial faces) becomes
not valid from the criteria of shell operation. I.e. its faces are self-intersecting. That is why you don't see the expected result.
Regards
Tue, 08/09/2011 - 11:37
Thank you Supervisor
there is clearly a (basic) change in the topology because a face will disappear
in my opinion the ideal system should provide a warning a then compute the solution without that face
thanks for your help
davide
Tue, 08/09/2011 - 11:55
+1
Exception are useful, also to inform a programmer of what's going on.
In terms of code quality its perhaps a useful idea.