# 2D drawing - centerline between two arcs

**URL:** <https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510>\
**Category:** Modeling Questions\
**Created:** [February 25, 2024, 11:13am UTC](https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510 "2024-02-25T11:13:31Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![Franz\_Kolenz](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@Franz\_Kolenz](https://discourse.shapr3d.com/u/Franz_Kolenz)\
**Post date:** [February 25, 2024, 11:13am UTC](https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510/1 "2024-02-25T11:13:31Z")

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Hi @,  
How can I draw a centerline between two concentric arcs?

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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:** [February 25, 2024, 12:19pm UTC](https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510/2 "2024-02-25T12:19:55Z")

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![image](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/8/5/858814d58474ab4ec39959001fcae073958a4b27.png)

If that’s not what you want then be more specific in you question.  
Or better show a screenshot with your drawing.

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**Author:** ![Franz\_Kolenz](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@Franz\_Kolenz](https://discourse.shapr3d.com/u/Franz_Kolenz)\
**Post date:** [February 25, 2024, 5:01pm UTC](https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510/3 "2024-02-25T17:01:54Z")

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Hi Xdrakosha,

thanks for your answer and video, but that’s not what I meant.  
I want to add a centerline between the two concentric arcs of the elbow, see below.  
But I could not figure out how to do that. I could only add centerlines between the two lines of the cylindrical part.

 ![Bildschirmfoto 2024-02-25 um 11.51.10](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/2/4/246c328758332c447406330d812a95c9755ce13a.png)

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**Author:** ![Yepher](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.shapr3d.com/yepher/32/8902_2.png) [@Yepher](https://discourse.shapr3d.com/u/Yepher)\
**Post date:** [February 25, 2024, 5:08pm UTC](https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510/4 "2024-02-25T17:08:14Z")

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Make another circle and change it to a construction line

![makeConst](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/5/e/5e6da9fcaf0a0a6001d367be43425061ab99f043.gif)

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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:** [February 25, 2024, 6:26pm UTC](https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510/5 "2024-02-25T18:26:06Z")

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> [@Franz\_Kolenz](#):
>
> I want to add a centerline between the two concentric arcs of the elbow

Can you show your sketch? Or at least draw line that you need on the image so I can understand that is the problem.

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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:** [February 25, 2024, 7:29pm UTC](https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510/6 "2024-02-25T19:29:58Z")

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Or maybe this helps more 🙂

[![](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/4/3/43d70bee937f1abb4d0726f880517df775dbb826.jpeg "Arc") ](https://www.youtube.com/watch?v=RyZZnf1FtvM)

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**Author:** ![Franz\_Kolenz](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@Franz\_Kolenz](https://discourse.shapr3d.com/u/Franz_Kolenz)\
**Post date:** [February 25, 2024, 7:37pm UTC](https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510/7 "2024-02-25T19:37:31Z")

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Thanks guys,

I know how to do it while sketching, but I need it on the 2D drawing.  
I added the centerline shown in red I would like to have on the drawing.  
Sorry for confusion, I thought I was clear when I mentioned in the topic “2D drawing”  
 ![Bildschirmfoto 2024-02-25 um 11.51.10](https://us1.discourse-cdn.com/flex002/uploads/shapr3d/original/3X/4/f/4f7cf6a1efc0ed18baf20dcc892d345a70389747.png)

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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:** [February 25, 2024, 8:09pm UTC](https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510/8 "2024-02-25T20:09:55Z")

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> [@Franz\_Kolenz](#):
>
> I know how to do it while sketching, but I need it on the 2D drawing.

My bad. Misunderstood you 🙂

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<div class="post-metadata">

**Author:** ![Franz\_Kolenz](https://avatars.discourse-cdn.com/v4/letter/f/c68b51/32.png) [@Franz\_Kolenz](https://discourse.shapr3d.com/u/Franz_Kolenz)\
**Post date:** [February 25, 2024, 8:40pm UTC](https://discourse.shapr3d.com/t/2d-drawing-centerline-between-two-arcs/30510/9 "2024-02-25T20:40:30Z")

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> [@Xdrakosha](#):
>
> My bad. Misunderstood you 🙂

No problem, I appreciate your efforts 👍