# Level 1 Training - Rail Revolve - faulty example

**URL:** <https://discourse.mcneel.com/t/level-1-training-rail-revolve-faulty-example/131899>\
**Category:** Rhino for Windows\
**Tags:** windows, mac, training\
**Created:** [October 19, 2021, 1:09pm UTC](https://discourse.mcneel.com/t/level-1-training-rail-revolve-faulty-example/131899 "2021-10-19T13:09:52Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![martinsiegrist](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/martinsiegrist/32/498369_2.png) [@martinsiegrist](https://discourse.mcneel.com/u/martinsiegrist)\
**Post date:** [October 19, 2021, 1:09pm UTC](https://discourse.mcneel.com/t/level-1-training-rail-revolve-faulty-example/131899/1 "2021-10-19T13:09:52Z")

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I’m going through the Level 1 Training Manual in preparation for a Rhino certification.

The example file Rail Revolve contains a misaligned rail curve and axis. The result of the rail revolve is a surface with a hole in the center. It looks wrong, obviously.

I don’t think finding this problem is part of the training and I think the example file should be fixed.

 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/c/3/3/c33ee878c68dabdd0cbf35e156b5e1e692172a44.jpeg)

[rail\_revolve\_bowl.3dm](https://discourse.mcneel.com/uploads/short-url/qvoy3FFBeum46rxaIdwoCBVb2Gi.3dm) (1.9 MB)

PS: replaced the file with centered geometry

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**Author:** ![Helvetosaur](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/helvetosaur/32/635974_2.png) [@Helvetosaur](https://discourse.mcneel.com/u/Helvetosaur)\
**Post date:** [October 19, 2021, 2:05pm UTC](https://discourse.mcneel.com/t/level-1-training-rail-revolve-faulty-example/131899/2 "2021-10-19T14:05:11Z")

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Confirmed. Axis is 0.009 out of plane. Good catch! @mary

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**Author:** ![martinsiegrist](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/martinsiegrist/32/498369_2.png) [@martinsiegrist](https://discourse.mcneel.com/u/martinsiegrist)\
**Post date:** [October 19, 2021, 2:16pm UTC](https://discourse.mcneel.com/t/level-1-training-rail-revolve-faulty-example/131899/3 "2021-10-19T14:16:42Z")

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Wouldn’t it be better to also move the whole sample geometry to the origin? In order to train users to build their geometry on the origin whenever possible?

 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/a/b/2/ab24bd8a09a05086e8a658e5d1e21a0f004dfd25.jpeg)

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**Author:** ![wim](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/wim/32/747482_2.png) [@wim](https://discourse.mcneel.com/u/wim)\
**Post date:** [October 22, 2021, 8:48am UTC](https://discourse.mcneel.com/t/level-1-training-rail-revolve-faulty-example/131899/4 "2021-10-22T08:48:23Z")

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Hi Martin -

> [@martinsiegrist](#):
>
> The example file Rail Revolve contains a misaligned rail curve and axis.

Thanks, I put this on the list as [RH-66044](https://mcneel.myjetbrains.com/youtrack/issue/RH-66044).  
-wim

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**Author:** ![mary](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/mary/32/764567_2.png) [@mary](https://discourse.mcneel.com/u/mary)\
**Post date:** [October 28, 2021, 5:31am UTC](https://discourse.mcneel.com/t/level-1-training-rail-revolve-faulty-example/131899/5 "2021-10-28T05:31:39Z")

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Hi @martinsiegrist,  
Thanks for the heads up here. @wim has create YT and I have reassigned it to DOC-284. It will be corrected in the next round of updates.

In the mean time, here are some suggestions, especially for those who teach Rhino:

1. Delete red line and use **End pt osnap** and **Ortho** to generate the _Axis_ in the **RailRevolve** command The Line is not a required part of this model. In fact, this is actually the more realistic way to do the **RailRevolve** without the line. A Rhino user would not make a line and then do the **RailRevolve**. It is just not necessary. This is how present this exercise when teaching.

2. Turn on all the layers. You will see there is a second set of curve to make the bowl.  
 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/2/b/6/2b6698b676be4c44b69ad510aa5b11cf11ed6982.png)  
The origin is between both set of curve.  
_Wouldn’t it be better to also move the whole sample geometry to the origin?_  
Since in many industries, like Architecture, it is not possible to model everything at the origin. It is also important to show that you can model away from the origin, as well.  

3. At this point in the course we have already covered **Cplanes** and the **Named Cplane** panel. Save a NamedCplane for each of the RailRevolve examples.  
_This way you will have each part at the origin of their own respective Cplanes._  
 ![image](https://global.discourse-cdn.com/mcneel/uploads/default/original/4X/d/c/1/dc144b0a7c397dc6282b18743a53e331013b2c3b.png)

4. Try this fixed file. Let me know if it works for you.  
[Rail Revolve.3dm](https://discourse.mcneel.com/uploads/short-url/hrCPRaF7zuhyfadqE8CiLrxs9mA.3dm) (2.8 MB)

Sincerely,  
Mary Ann Fugier  
McNeel Technical Support and Training  
Seattle, WA

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<div class="post-metadata">

**Author:** ![martinsiegrist](https://sea3.discourse-cdn.com/mcneel/user_avatar/discourse.mcneel.com/martinsiegrist/32/498369_2.png) [@martinsiegrist](https://discourse.mcneel.com/u/martinsiegrist)\
**Post date:** [October 28, 2021, 6:44am UTC](https://discourse.mcneel.com/t/level-1-training-rail-revolve-faulty-example/131899/6 "2021-10-28T06:44:37Z")

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Thanks for your reply.

> [@mary](#):
>
> Try this fixed file. Let me know if it works for you.
> 
> [Rail Revolve.3dm](https://discourse.mcneel.com/uploads/short-url/hrCPRaF7zuhyfadqE8CiLrxs9mA.3dm) (2.8 MB)

Regarding the fixed file, the red line on the bowl example is still off. Nevermind.