Creating threads in Rhino

Rhino
,
1

I am struggling with making a thread in Rhino following this link: Modeling Screw Threads on Vimeo

I get stuck in the moment when it says to extend helix. It just won´t work. Cannot grab the end point and move them freely as shown.
Is there another better explanation, maybe even using the german version which I am trying to use?

2

you stuck at which video (link goes to playlist with 2 videos) at which timestamp ?

3

you struggle with the _extend (press enter for dynamic)… at 1:09 of first video ?

4

Got one step further, then I get stuck once I try to round edges between those two united objects,
5 Minutes ago I figured it, I believe almost completely. Took me almost the whole day of trial and error.
Once I will have figured it all out what I need, I maybe 90 years old if I make it :wink:

5

Now what does this mean?

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grafik
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6

a boolean operation - error
the dot s have more info if you select a single one and read it s properties

7

Cannot selct or see an option for selecting and getting info. Just shows these. Weird enough further down there is nothing marked while the construction is the same.

8

When I fillet this, it looks ok:

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If I then want to unite the whole thing as single solid I get this:
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How can I make this a single solid item?

9

Hi @Walter_Born
The low pitch of your thread has the fillet overlapping itself all over the place. You need to either change the pitch, leaving enough room for the fillet from thread to cylinder, or you need to fillet/blend the thread to itself, so to speak, in the internal area. Post a 3dm file if you need something more tangible, in terms of help.
-Jakob

10

test ü.3dm (2.2 MB)
Testfile…

11

Why don’t you just download the screw, bolt, etc. you need or use the BoltGen Rhino plugin?

12

As it is a custom part, not a bolt.

13

There are videos for those who must self-model such bits and bobs.

14

Thanks again. Will check more Youtube then. Already tried several.

15

Hi @Walter_Born
Here’s how I would approach it. Trim the fillet in between the threads out, leaving room the a transition piece (made with Patch in the end) and use BlendSrf to create the surface between the threads.
test ü_JN.3dm (1.0 MB)

HTH, Jakob

16

we had this extensive discussion about threads here:

depends a bit what s the next step / export etc… but helix-like surface can be quite problematic.. at least that s my opinion / experience.

17

if you split your thread surface in two, you can build a Fillet between the two parts using FilletSrf:

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In Rhino WIP, you can fillet, trim and join in one operation, and once that is done, you can extract the outer two cylinder parts to make two remaining fillets with smaller radius, e.g:

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18

Thanks for all the solution approaches so far. I will have to dedicate some more time I guess on that topic and try to translate all your help into german language and find the right comands in Rhino/german as well.