Barley Twist Spirals

[jeff hammond]

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]

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]

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

[pbacot]

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

[gilles]

@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]

Made in one shot with screw1_5.rb.

AND it works also with components.

---

[Dave R]

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]

the new classic

[gilles]

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]

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

That's not a barley twist either.

[Dave R]

@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]

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]

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]

@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]

Here is a step by step.

---

---

---

---

---

---

---

---

---

[archturn]

@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]

@gilles said:

Here is a step by step.

Nice rope twist.

[archturn]

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]

Its up to you to create the good profile.

You can also do this with screw:

---

[Dave R]

archturn, you could use the method I showed and create the transitions when you've finished. There isn't any reason you couldn't fit it to the rest of the turning. I did on the table legs. The transitions are similar to creating the pommels which I've showed in several other blog posts so I didn't bother with them in that one. The Screw plugin is nice, too. although you can do multiple starts the way Gilles shows, I would still make a single turn as a component and copy it as I did in the blog to keep file size down and make it easier to adjust the length.