Barley Twist Spirals

archturn · 22 Jan 2013, 22:51

I'm looking for a way to model my stair newels in Sketchup. The attached barley twisted newel was made in my CAD program but I am hoping for a method to do the same in Sketchup. Would appreciate any help.

jeff hammond · 22 Jan 2013, 23:32

do you mind giving a little background first? what's your current sketchup level? are you ok with using plugins or would you prefer to do it using native sketchup tools?

archturn · 22 Jan 2013, 23:52

I'm probably an intermediate user. I'm fine with using plugins. I've looked in vain though to find one that will help

Dave R · 23 Jan 2013, 00:33

This shows how I do them. And a couple of examples.

pbacot · 23 Jan 2013, 02:54

screw.rb can make this pretty well and fast. But I bet the geometry created by Dave's method would be nicer.

gilles · 23 Jan 2013, 10:02

@pbacot said:

screw.rb can make this pretty well and fast. But I bet the geometry created by Dave's method would be nicer.

There is no reason, it depends of how many steps you type in the prompt window.

gilles · 23 Jan 2013, 10:19

Made in one shot with screw1_5.rb.

AND it works also with components.

Dave R · 23 Jan 2013, 10:35

Gilles, yours shows a nice spiral or screw but that's not a barley twist. The barley twist consists of multiple starts. It is possible to make the barley twist with Screw, though.

This is a three-start barley twist.

pilou · 23 Jan 2013, 10:43

the new classic

gilles · 23 Jan 2013, 10:48

Sorry Dave, there are two starts and I could have done n starts in one shot.

OFF TOPIC

components plus profiles in one shot:

Dave R · 23 Jan 2013, 10:50

Pilou, you trot that video out every time someone asks how to draw anything.

That's not a barley twist either.

Dave R · 23 Jan 2013, 10:55

@gilles said:

Sorry Dave, there are two starts and I could have done n starts in one shot.

Show the setup. And which version of Screw are you using.

gilles · 23 Jan 2013, 11:07

screw1_5.rb.

select 3 profiles (in the following case), set start point, set end point, enter n steps n turn and go.

Dave R · 23 Jan 2013, 11:53

Thanks. that should help the OP.

Isn't it great there are usually multiple ways to arrive at the same point in SketchUp?

And you finally drew a barley twist. Here's a cutter profile for that.

Gaieus · 23 Jan 2013, 12:14

@dave r said:

Pilou, you trot that video out every time someone asks how to draw anything.

That's not a barley twist either.

True but otherwise a brilliant solution!

(I could imagine Kito Raupp is Pilou himself in a humble disguise)

gilles · 23 Jan 2013, 13:58

Here is a step by step.

archturn · 23 Jan 2013, 14:50

@gilles said:

Made in one shot with screw1_5.rb.

AND it works also with components.

This is what we call a rope twist not a barley twist. The barley twist has another (interior) radius. The rope twist looks like rope - though your method may work for a barley twist as well. David R's is definitely a barley

Dave R · 23 Jan 2013, 14:54

@gilles said:

Here is a step by step.

Nice rope twist.

archturn · 23 Jan 2013, 15:09

Dave R
Love your solution but I need to fit it to the other part of my newel. Gilles method looks like it will work. In CAD I'll usually do a sweep of the newel profile then draw my barley twist profile - sweep the barley profile with the correct pitch then subtract it from my newel sweep. I wish I could do it this way (specifically the subtract function) in SU since this yields the most realistic geometry - though again Gilles looks pretty right (just needs more interior radius to be classified as a true barley twist). Thanks

gilles · 23 Jan 2013, 15:18

Its up to you to create the good profile.

You can also do this with screw: