Sweep1 help for handrail

Hi all I’m trying to create a sweep for a handrail for a staircase that has 90degree turn, I have used road like top and it works quite well but as you can see its not quite tangent with on the 90 degree pitched turn. Can anyone guide me on how this on How I can control this to be more accurate? do I need sweep 2 of so I need some help understanding the process as I am new to this. I have seen other models with handrails sweeping perfectly done with rhino… any help or tips appreciated. Thanks
Stair Rail test 2.3dm (203.7 KB)

I’d create both sides of your handrail and build the transitions with blend curves and individual surfaces

it’s not tangent currently because your original curve is not tangent to start with.

always get your curves perfect first and your surfaces will most likely follow.

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Hello- is this what you are shootiong for?

Stair Rail test 2_Maybe.3dm (223.3 KB)


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Hi thanks but I am pretty certain The sweep path is completely tangent to the two straight lines its the sweep that kinks out, I don’t really understand why, is there a better way to set the sweep path up or is it because I am putting the sweep path in the middle of the profile or is there adjustment in the sweep command I can use? ultimately this is a test and when I know the square can be swept I was going to design the handrail profile so it won’t just be a square hence why I thought sweep is the best tool, would blend curves work for a more complicated shape?

Hi Pascal

Thanks it looks good, ultimately I am not looking to have a square handrail, I will develop the design and handrail profile once I know it can be modelled along the path,

  1. Was this a sweep?
  2. if not a sweep can I achieve the same thing with more complicated handrail section/profile?

A bit of a background to this project, which may help to understand:

I am modelling a staircase which will have a 90degree turn and a continuous wreathed handrail.
I am using inventor as that is what we are generally using for our manufacturing drawings currently, I have discovered that inventor can’t produce this kind of sweep and loft doesn’t work either.

So it was suggested I import the inventor model including sweep path etc in rhino as a .step file and try the sweep there where it would be possible and then export that part back in to inventor to add to the master model.

It works really well exporting and importing but I am still struggling with the modelling of the handrail, I am up for other techniques other than sweeping, but I will need some guidance and also as the design progressives so will the handrail shape.


HI Kyle although it was in tangent, as I was sweeping the path through the middle it messed with the tangent at the top and bottom of the cross section as its on a pitch, I tried it again with a a more complicated shape and positioned the sweep path central but at the bottom of the section and it works very well! does makes sense and look right to you?


I’m still struggling a bit with this as get distortions for some reason if anyone can take look at this video. Is the "Tangent Handrailing Method" dead? Part 2 - YouTube as this is essentially what I want to do hes drawn the pitch in elevation and then wrapped it around his plan curves and then has used sweep I think he has used the other rails as guide rails would this be sweep2?

I need help understanding how to wrap an elevation around a plan curve to create the geometry to sweep
His model looks perfect and is what I am aiming to do.


Is this what you want to get? (I’ve included a lower horizontal section assuming that you will have one, as it makes creating the rails easier.)

Sweep 2 will give better results than Sweep 1. You want your two rails to be on the inside of the curve. I created my rails by using arc blends between two matching straight edges here:

If you don’t have suitable edges, put a bounding box around your profile and use the top and bottom longitudinal edges.

I then used Sweep 2 with the Maintain Height option ticked.

Stair Rail test 2-j1.3dm (389.0 KB)


(Using Rhino 5)

Here’s a Sweep1 variation where the path is the top edge of a vertical surface and the sweep is set to ‘Follow surface’.


Stair Rail test 2-j1_PG.3dm (595.7 KB)


That looks better. If I was modeling this for the square handrail, I’d blendcrv each corner of the square individually with history, then make edgesrf from each 4 sided patch, then adjust the blendcrvs using history to make any needed adjustments until I got it right.

using history for the whole process will allow you to go back and rub blendcrv again, use the edit option, edit the curves and have the entire form update with history.

Hi thanks for all of these suggestions I am working on the path geometry and then I will try some of these out, so many options in Rhino! One thing I have tried that worked really well was sweep2 and add slash to top and bottom rails with perp snap on between rails. this worked really well and cleared up any distortion I was getting


I would use “Blend surface” with G1 tangency at both ends.