# Paramétric Hélix slot probleme…(and solution)!

**URL:** <https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011>\
**Category:** Modeling Questions\
**Created:** [May 18, 2025, 10:15am UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011 "2025-05-18T10:15:41Z")\
**Posts on this page:** 16\
**Page:** 1

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**Author:** ![Hell3d](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/hell3d/32/27000_2.png) [@Hell3d](https://discourse.shapr3d.com/u/Hell3d)\
**Post date:** [May 18, 2025, 10:15am UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/1 "2025-05-18T10:15:41Z")

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Hello, I have a problem making a part with very precise tolerances.

I can’t build the gray part guide to create a 36° rotation movement for a translation of the red axis of 24 mm high.  
The yellow axis must remain in contact with the two surfaces.  
Can someone explain a method to me? Thanks

 ![IMG_1473](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/5/3/53342227c18ce3a90f83bda5715b2d06dded257b.jpeg)

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**Author:** ![Xdrakosha](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/xdrakosha/32/24881_2.png) [@Xdrakosha](https://discourse.shapr3d.com/u/Xdrakosha)\
**Post date:** [May 18, 2025, 11:28am UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/2 "2025-05-18T11:28:50Z")

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If I understand you right you want to make something like that?

> **[Shapr3D - Review Links](https://collaborate.shapr3d.com/v/nKQbkDGxdD8whCjo_yQ2C)**
>
> Review designs together. View models and add comments directly to your 3D design.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/8/c/8cea67de0f4ed32ef033a7ef0ce7de7a43b4a05c.png)

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/8/c/8cd1007e1fb6850c9e864d51b2a1bd8642cdbe42.jpeg)

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**Author:** ![BKE](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/bke/32/31690_2.png) [@BKE](https://discourse.shapr3d.com/u/BKE)\
**Post date:** [May 18, 2025, 12:04pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/3 "2025-05-18T12:04:04Z")

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Here is an interesting thread

> [@Revolve or sweep a body like a end mill to cut out a curve](https://discourse.shapr3d.com/t/revolve-or-sweep-a-body-like-a-end-mill-to-cut-out-a-curve/31729):
>
> Hello community, I am new to the community and would like to say hello. I used shape3d a lot so not really unexperienced but now I can’t find a solution for this issue and I would appreciate any help. I’m having trouble getting this curve profile to look like it was generated with a milling machine. I tried using the sweep and revolve tools to subtract the red area in the image from the cylinder. In reality, a end mill (blue) that is perpendicular to the longitudinal axis would cut the curve a…

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**Author:** ![Hell3d](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/hell3d/32/27000_2.png) [@Hell3d](https://discourse.shapr3d.com/u/Hell3d)\
**Post date:** [May 18, 2025, 5:49pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/4 "2025-05-18T17:49:23Z")

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Yes, absolutely  
I tried several techniques, but never succeed, could you explain your method thank you very much…

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**Author:** ![Xdrakosha](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/xdrakosha/32/24881_2.png) [@Xdrakosha](https://discourse.shapr3d.com/u/Xdrakosha)\
**Post date:** [May 18, 2025, 5:55pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/5 "2025-05-18T17:55:51Z")

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I did two holes in edge points

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/d/2/d211213bc2e79a1b9ec42c906287c5b2640f9578.jpeg)

Then drew a sketch in the start position and revolved 36 degree 24 mm

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/d/b/db61149e34f073abdd3cb99d3a04c04531a5212c.jpeg)

Then substracted revolved body from tube

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/9/b/9b25b6d0c501b3bda7da56733f4c3fe2ef64454b.jpeg)

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/3/7/370e44d20b9044b911992a23469bf6ff6f647983.jpeg)

I decided to 3d print this model, that’s why I added 0.1 mm tolerance

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/9/a/9abac8126e08e1228c2c4b6b984a93e15a11648c.jpeg)

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/9/f/9f6269b168671c71c58b8f553c80fa219cf6fc27.png)

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<div class="post-metadata">

**Author:** ![Hell3d](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/hell3d/32/27000_2.png) [@Hell3d](https://discourse.shapr3d.com/u/Hell3d)\
**Post date:** [May 18, 2025, 6:31pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/6 "2025-05-18T18:31:12Z")

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Amazing… How simple you made that…  
I was just reading the topic From 2024… and the complex solution they came up.  
Thank you very much for your help.

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**Author:** ![Xdrakosha](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/xdrakosha/32/24881_2.png) [@Xdrakosha](https://discourse.shapr3d.com/u/Xdrakosha)\
**Post date:** [May 18, 2025, 6:37pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/7 "2025-05-18T18:37:10Z")

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> [@Hell3d](#):
>
> complex solution they came up

They did precise math calculations. I just eyeball it 🙂

Main problem is to find precise angle of that sketch

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/6/0/60440b4fea5478eb815e2f320008e84b7a5ef7e5.jpeg)

With the angle of 111.35 degree I got most accuracy of 5.9918 mm instead of 6 mm

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/6/8/68ef492808061d0ef59a7e1de98844b968a57a96.jpeg)

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/4/e/4e63b6132688918c6839825dab72b0426fdf3ab5.jpeg)

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<div class="post-metadata">

**Author:** ![Hell3d](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/hell3d/32/27000_2.png) [@Hell3d](https://discourse.shapr3d.com/u/Hell3d)\
**Post date:** [May 18, 2025, 6:59pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/8 "2025-05-18T18:59:29Z")

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I was asking myself the same question… I made some visual corrections to find the best angle, but the solution works well, more than enough to create a prototype with my 3d printer…🙂

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**Author:** ![TigerMike](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/tigermike/32/32650_2.png) [@TigerMike](https://discourse.shapr3d.com/u/TigerMike)\
**Post date:** [May 18, 2025, 8:14pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/9 "2025-05-18T20:14:38Z")

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Here’s a somewhat precise method. My slot is 4mm wide and the rod that slides up the slot is 3.6mm dia. The rectangle used in the revolve is rotated 54° which will be normal to the 36° angular slot that is 24mm high. After the revolve I added 2mm length to each end t compensate for the diameter of the 3.6mm rod. Hope this helps.

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**Author:** ![Xdrakosha](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/xdrakosha/32/24881_2.png) [@Xdrakosha](https://discourse.shapr3d.com/u/Xdrakosha)\
**Post date:** [May 18, 2025, 8:24pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/10 "2025-05-18T20:24:46Z")

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> [@TigerMike](#):
>
> The rectangle used in the revolve is rotated 54°

How did you come to 54 degree? Have you used any formula?

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**Author:** ![TigerMike](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/tigermike/32/32650_2.png) [@TigerMike](https://discourse.shapr3d.com/u/TigerMike)\
**Post date:** [May 18, 2025, 8:31pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/11 "2025-05-18T20:31:50Z")

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Not sure if this is totally precise or not.  
90° minus 36° angular rotation = 54° starting angle of the slot that moves upward. Does that explain it?

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**Author:** ![Xdrakosha](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/xdrakosha/32/24881_2.png) [@Xdrakosha](https://discourse.shapr3d.com/u/Xdrakosha)\
**Post date:** [May 18, 2025, 8:37pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/12 "2025-05-18T20:37:46Z")

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> [@TigerMike](#):
>
> 90° minus 36° angular rotation = 54° starting angle of the slot that moves upward

Quite interesting. I used the same method, which I explain above, but to get precise result had to rotate rectangle on ~68 degrees. Only difference I have 6mm width slot and 6 mm rod.

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**Author:** ![TigerMike](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/tigermike/32/32650_2.png) [@TigerMike](https://discourse.shapr3d.com/u/TigerMike)\
**Post date:** [May 18, 2025, 8:57pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/13 "2025-05-18T20:57:14Z")

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I too tend to eyeball designs (meaning examples). I used an intuitive approach on this one getting the 54°.  
Each rod is copy elevated 6mm and rotated 9°.  
Note, my first post said ‘somewhat precise’. 😉

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<div class="post-metadata">

**Author:** ![Xdrakosha](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/xdrakosha/32/24881_2.png) [@Xdrakosha](https://discourse.shapr3d.com/u/Xdrakosha)\
**Post date:** [May 18, 2025, 9:22pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/14 "2025-05-18T21:22:22Z")

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> [@TigerMike](#):
>
> Note, my first post said ‘somewhat precise’.

Yeah, I missed that 😃

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**Author:** ![PEC](https://avatars.discourse-cdn.com/v4/letter/p/67e7ee/32.png) [@PEC](https://discourse.shapr3d.com/u/PEC)\
**Post date:** [May 18, 2025, 10:58pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/15 "2025-05-18T22:58:13Z")

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Hi

I made a precise parametric design some time ago to do this kind of slot so I share it here.  
It is accurate even for large values of the helix angle and thick tube; it also handles clearance.  
You just have to set 7 variables:

- d\_out, d\_in, l : dimensions of the tube
- d-pin : diameter of the pin
- e, alpha, clearance : dimensions of the slot

[Parametric Slot milling 0.7.shapr](https://discourse.shapr3d.com/uploads/short-url/7AYJIM3LosWuBY0ChcHFddreDjT.shapr) (626.1 KB)

 ![IMG_0110](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/b/d/bd6cc20da791bc3012ec9a7da6918899b530f56f.jpeg)  
 ![IMG_0111](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/b/a/bafea919aa7972792e77e77673be71280a511bf0.jpeg)

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<div class="post-metadata">

**Author:** ![kabocha](https://avatars.discourse-cdn.com/v4/letter/k/f04885/32.png) [@kabocha](https://discourse.shapr3d.com/u/kabocha)\
**Post date:** [May 20, 2025, 2:28pm UTC](https://discourse.shapr3d.com/t/parametric-helix-slot-probleme-and-solution/38011/16 "2025-05-20T14:28:01Z")

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Pec thanks for your file, I learned a lot. Enough to maybe manually produce what you did.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/b/7/b722789acf08acf0ec69d72446b763881678fbb3.jpeg)  
 ![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/c/f/cf65fc4a4cb9c6e937195552b62cb40c7fb348ec.png)