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Full Version: barrel rifleing in MOI3D

From: GuyLuke
23 Jan   [#1]
Hi All.

Can anyone give me some tips on the best process to complete this in MOI3D?

https://www.youtube.com/watch?v=8r3E0oU2Ws4

I mainly want to know the best process to get a nice smooth twist in the 'star' shape. I tried a few methods like sweep along a twist and lofting between two rotated shapes but I was not getting a satisfactory result.

As you can see from my file, the loft is 'straight' and does not curve between the shapes.

Thank you.

Attachments:
rifling.3dm


From: Phiro
23 Jan   [#2]
I think that youtube video is not the easiest process.

A possible easier process is
- Drawing your star with the profile you prefer. I use your for exemple.
- Extrude the star
- Twist the extrusion
- Prepare a pipe with extrude
- Boolean Diff
From: Phiro
23 Jan   [#3]

From: Michael Gibson
23 Jan   [#4] In reply to [#1]
Hi Guy, yes Phiro's method using the Twist command is better, it should give high accuracy while at the same time less work to set up since you only need one profile curve.

The Twist command is under Transform > Deform > Twist:
https://moi3d.com/4.0/docs/moi_command_reference8.htm#twist

Thanks Phiro!

- Michael
From: GuyLuke
23 Jan   [#5]
Excellent! Thank you so much!
From: bemfarmer
23 Jan   [#6] In reply to [#1]
Hi GuyLuke,

As pointed out in the comments, the video modeling could be less complex, with better geometry tools.

A 2d profile of one groove is useful. This can be done in metric units.

Switching to inches, one helix is useful. The helix rotates 360 degrees in ten inches.
Left or right handed.

Sweep the helix with the profile to create one groove.

Circular array the groove, by 6 (copies).

Etc.

-Brian
(Have not yet viewed your .3dm.)
( There is more than one method. )