Creating helical path?

[LarryO]

Is anyone familiar with how one goes about creating a helix path line?  (corkscrew)

I have a radius of 4153mm sweeping 10.93° and rising/dropping 473.7mm.

Ultimately I want to have a rectangular profile follow the path so I can clip off a series of pickets and posts or merge it with those same pickets and posts.

 

FYI: initially I tried to use the staircase tool to do this for me but I couldn't get the posts to land in the same location on their respective treads with that tool. I also am required to step the bottom rail, which I achieved easily enough.

Edited January 8, 2021 by LarryO
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[Kevin Allen]

Model>3D Powerpack>create helix spiral?

 

[markdd]

Have you tried the Helix spiral command  from the  3D power pack section of the Model Menu?

[LarryO]

I've attempted to use it but I'm not sure what object it is expecting one to have preselected and there doesn't appear to be a means to enter the sweep of the arc only a start location.

[LarryO]

I found a video. Thanks all.

Having to use a line to determine the centre axis and with its length defining what I thought would be called the pitch is what I was missing.

For some reason VW uses the term pitch to identify the sweep of the arc. I find that puzzling.

If I used VW's arrangement of terminology to get some steel rolled it most certainly would not come back as expected. hehehe

[LarryO]

Well in the end I used the stair tool to create the top rail and just threw away all the posts and pickets it creates.

The helix tool rotated the rectangular profile such that I could not see how one was to align the start to the end of an adjacent identical segment.

😞

[Benson Shaw]

On 1/8/2021 at 11:25 AM, LarryO said:

I found a video. Thanks all.

Having to use a line to determine the centre axis and with its length defining what I thought would be called the pitch is what I was missing.

For some reason VW uses the term pitch to identify the sweep of the arc. I find that puzzling.

If I used VW's arrangement of terminology to get some steel rolled it most certainly would not come back as expected. hehehe

@LarryO 

 

You probably already have a working solution, but thought I would put in a visual with the helical spiral and the duplicate array tools in action.

 

Is this something like your goal?Is the total rise 473.7? Is the total sweep 10.93°? This seems like seating rather than stairway? Or maybe I'm totally missing.  The top rail would be way better as a single EAP using a helical path with the total sweep and total rise.

 

The axis object is more of a partial pitch, eg pitch for the specified sweep at creation, rather than for a full turn. The Helical Spiral tool has some confusing parameters, but it does work. The sweep parameter should be included in the OIP so that one could extend the spiral at same pitch.  The angular direction seems to start at noon and run clockwise, rather that the standard euclidian 3 o'clock heading anti clockwise.  I will post a wish to bring it into compliance with standard radial conventions.

 

-B

 

Helical Stairv2021.vwx

Edited January 11, 2021 by Benson Shaw
add file

[LarryO]

As mentioned I couldn't utilize the helix line as a path for my rectangular profile due to some rotational issue that I don't quite comprehend. You can see two of my efforts in the picture. The top most was the closest to being correct where I had rotated the rectangle 45° in an attempt to plumb the profile's sides. The middle profile is what the tool produced without corrections. I reminds me of the angle a person might be traveling at while riding a water slide due to centrifugal force.

 

I eventually used the standard sweep tool. I calculated manually what the height of the profile would be when sliced at the angle of the stair's incline along the radial centre line of the railing's location. (geometry courses have a purpose) The result is the pink profile embedded over the profile that the stair tool created. You can also see the helical line I forgot to delete that I was attempting to use as a path along the top centre of the railing.

 

FYI the 10.93° was the angle from post to post, equivalent to three tread nosings. Hence the rise of 473.3 was also across those three risers. 4153 is the radial centre line of the railing.

[markdd]

Have you tried making a stair using the Deform tool? Bend solid mode using the finite length option. I'm not sure what your end result needs to be, but this took me about 90 seconds to model....

Edited January 11, 2021 by markdd

[LarryO]

@markdd

Thanks for the thoughts, The stair profile was thankfully the easy part. My focus in this instance is on manufacturing the custom railing; metal fabrication shop drawings.

[Matt Overton]

The Sweep... command allows the profile you are sweeping to pitch upwards as it goes.

Allowing it to overlap each full circle and create a corkscrew path like you see on the outside a stadium.

 

That might help you do want you need.

[LarryO]

@Matt Overton 

Yes, SWEEP was the solution. The tool keeps the profile plumb to the work plane rather than perpendicular to the incline of the path. So I needed the slope to determined the distortion required for the vertical face of the profile so that the thickness of the steel bar capping the guard railing remained at 15.9mm.