Barley Twist Spirals

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.

gilles

@dave r said:

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.

Totally agree with this.

charly2008

Hi,
here are two more options

archturn

I can see that I should have been visiting the forum more frequently instead of pulling my hair out. Awesome!!!

Dave R

Yes. You should have. And as I wrote before, there's more than one way to arrive at the final result in SketchUp. This is a great example.

archturn

@charly2008 said:

Hi,
here are two more options

Charly
I'm wondering how to use the "follow me keep" plugin". I installed it and though it shows up in my plugin menu nothing seems to happen when I click it.

massimo

You have first to select both the path and the face and then run the plugin.

gilles

Just a question: why use two plugins instead of one which does very well the job?

archturn

@gilles said:

Just a question: why use two plugins instead of one which does very well the job?

I'm going to try them all. I remeber some time back trying the "draw helix" without the "follow me keep" tool. That was one of the times I gave up. The result from using the native "follow me" is pretty ugly so I thought I would see what this tool was all about.
Again, I wasted a lot of time by not coming here first.

archturn

@gilles said:

screw1_5.rb.

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

Could you elaborate on using screw1_5??

gilles

Will do later, its late here in France and I should sleep.

jeff hammond

use a whole bunch of profile curves then apply wonky style?

dale

Just a quick question. In reality, can you turn a Barley Twist, or is it more of a carving exercise?

Dave R

Dale, barley twists can be turned, sort of. There's a machine that combines a router with a lathe and gears them together for creating barley twists and other ornamental milling. Check out this link. I used to have one of their machines and used it a lot. Of course now with CNC-driven equipment, it gets even more sophisticated. I can't say I would recommend dealing with the company but the idea was interesting.

dale

Thanks Dave, really interesting machine. I often wish I was a machinist, boy there would be trouble then.

archturn

@dale said:

Just a quick question. In reality, can you turn a Barley Twist, or is it more of a carving exercise?

Here are two videos of turning a barley twist and then a rope twist on my machine.

http://www.youtube.com/watch?v=LcjVLg0ql7c
Barley Twist

http://www.youtube.com/watch?v=0zVD22NqgSc>
Rope Twist

dale

That's Great. So can you directly import from SketchUp to you machine?
( Oh and, I guess I'm still living in the past, as I was thinking of how difficult if not impossible to turn it by hand. )

archturn

@dale said:

That's Great. So can you directly import from SketchUp to you machine?
( Oh and, I guess I'm still living in the past, as I was thinking of how difficult if not impossible to turn it by hand. )

My machine is not a full CNC but a step below it. It is a hydraulic copier so it traces a profile. The indexing function (used for the twisting) however is computer controlled so the setting up of gears and indexing pins that Dave R referred is not necessary. The templates I use for the turning profile are drawn in CAD and sent to a machine shop with a laser CNC so I can get a pretty fine template for tracing