[Solved] Need help modelling a rifled barrel

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Shalmeneser
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Re: Need help modelling a rifled barrel

Post by Shalmeneser »

nobeltnium wrote: Tue May 30, 2023 10:03 am
: PartDesign_AdditiveHelix is not always a friend
May i ask why? What happen if multiple sketches are on the same plane?
The 4th pattern doesn't show when the 'groove' sketch is coplanar with the cylinder face.
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adrianinsaval
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Re: Need help modelling a rifled barrel

Post by adrianinsaval »

nobeltnium wrote: Tue May 30, 2023 2:18 pm Oh and i also notice that when using the helix like papyblaise did, my models outer surface have this weird artifact. Can i some how get rid of it?
8ebd9b224eb590ebc9a4.jpg
May take on this is that you should not use additive helix but rather make a tube and then use substractive helix for just the grooves. Using one additive helix for everything means probably everything is a bspline surface which is much more computationally expensive than a simple cylinder.

disclaimer: I say this judging just by the images, I have not opened any of the files here
nobeltnium
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Re: Need help modelling a rifled barrel

Post by nobeltnium »

May take on this is that you should not use additive helix but rather make a tube and then use substractive helix for just the grooves. Using one additive helix for everything means probably everything is a bspline surface which is much more computationally expensive than a simple cylinder.

disclaimer: I say this judging just by the images, I have not opened any of the files here
I've been experimenting with Additive Helix and Subtractive Helix for the past 2 days on multiple models. And i must agree with you Subtractive is better. It doesn't have that weird artifact on the surface and also fine tuning the groove depth, angle and width is alot easier.
On performance though, both methods are about the same. At least on the scale that i'm working on.
Nobeltnium
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Re: Need help modelling a rifled barrel

Post by nobeltnium »

Shalmeneser wrote: Tue May 30, 2023 9:00 pm The 4th pattern doesn't show when the 'groove' sketch is coplanar with the cylinder face.
Now I see.
I also figured out that instead of Additive, if i use Subtrative to "cut" the groove into the tube, it doesn't have that problem of the pattern showing at the sketch base
eee0cb1307b6d9e880a7.jpg
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Nobeltnium
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