Again... Filletting and Booleans

[TOXE]

I know that is a top ten argument to discuss, but i have Amapi Pro since few days and NURBS are supercool, but for now i'm not able to understood completely their behaviors and characteristics. Example: why i can't fillet the green area? I've tried some different radius like Totyo have said in the previous post but don't work.
Someone have an additional advice?

By the way, because it's my first post, i want to say that i'm really glad to be here

-TOXE

:D

[Thomas]

It seems taht for this aera, you use a sphere and the boolean tool, no ?

If you have your step before the boolean, make a rotation of 90° of your sphere in order to don't have the yellow line from the sphere (inside the resulted circule)

By the way, do you have your model befre the boolean operation ?

[TOXE]

Thanks Totyo,

Ah, if you intersect the yellow line a boolean result incorrect?
I have a lot to learn about nurbs...

Yes, i have used a deformed sphere

Eheh, i've read some times your message to understand that "befre" is before, i've confused it with BREP :?

By the way i have attached the file before befre, hem, boolean

-TOXE

[Thomas]

hehe, sorry for my typing mistakes
Well well.. it works for me, but with a small chamfer value... and with a rotation of the sphere...

But it works really better on next update of Amapi Pro (don't ask me for a shipping date )
here is the file in attachement.

By the way, I know where the problems comes from (take a look at the snapshot)

[Shonner]

The yellow line from the sphere shouldn't cause a problem because the fillet worked with the smaller cut.

Maybe TOXE wasn't using crack-free NURBS. That could be the problem.

[TOXE]

Thanks for the file Thomas,

i'll wait for the next update...

Hi Shonner, glad to see you here :P What is the difference beetwen crack-free nurbs and the type that i've used?

-TOXE

[Shonner]

Crack-Free NURBS uses a more precise algorithm for calculating poly curves within a NURBS surface. Expect more facets in your model though.

[f.ip2]

hi shonner

i turned on the adap. and crack free nurbs mode but i still cannot champfer most edges. it only works when i scale down the sphere
so it does not intersect so many other nurbs areas.

i added a sphere on my own rotated this one scaled it down
and applied also a rotated cylinder to cut the volume and in my
file i attached i cannot champer even one edge at all.
even with very small values.

any clue? or is this just a current limitation in amapis nurbs kernel?

http://www.jrkuhnen.de/telephone.a3p

claas

btw: is it normal that with crack free tes. nurbs amapi´s calculation time
for nurbs operations are increasing a lot?

[Shonner]

Yes. Crack-Free NURBS requires more RAM and CPU speed to calculate the smoother polygons.



Here is your phone in standard NURBS mode. There is a problem with the symmetry. This can cause chamfering to not validate properly.




Here are the two cuts being made into the phone. The sphere and cylinder. I would try completing a cut from one of these first before attempting the next cut. Then doing a chamfer after both cuts have been made rather than inbetween each cut.

[f.ip2]

mh i just check the file conversation from cobalt into amapi.
iges gets in pretty clean but not crack free. i think the cadance
will close this gab.

i encountered even filleting issues with a simple sphere and cube.
for some reason amapi does not want to smooth the intersection edges.

i cross checked it in cobalt and it is possible even with filleting a fillet and
with different fillet shapes.

i find the workflow in amapi a bit confusing. the DG like the construction history in cobalt should let me access each option i did like chaning the
champfer radius for a selected edge afterwards. dont it? or is the DG limited to transpate objects (scale rotate) and translate controll points?

files are attached.

[Shonner]

Or you can weld the sphere and cylinder together and use that piece to cut with. Then chamfer the result.

[Thomas]

I cannot chamfer the IGES import, it seems that the sphere have some problems where the chamfer are (a strange gap you speak of...)

You have to know that the chamfer works beter in 7.15

[Shonner]

Originally Posted by f.ip2

i find the workflow in amapi a bit confusing. the DG like the construction history in cobalt should let me access each option i did like chaning the
champfer radius for a selected edge afterwards. dont it? or is the DG limited to transpate objects (scale rotate) and translate controll points?

I think Amapi 7's DG history can only remember 4 or 5 steps for each object made.

I collapsed the DG a bit so that filleting would work after your object cuts.



Here is the fillet/chamfer of boolean.a3p in Normal NURBS mode.




And the same fillet/chamfer in Crack-Free NURBS mode.




There was a validation problem with boolean2.a3p in Normal mode. The fillet/chamfer completed anyway.




And the same fillet/chamfer using Crack-Free mode.

[Shonner]

TOXE,

I'm curious how your phone model ended up. The 7.16 patch for Amapi Pro does an amazing job now with boolean fillets in Standard NURBS mode without having to rotate spheres first. I'm able to chamfer just about any odd angle now without getting "-" warning signals.