I have been asked to post instructions on Alternating Wraps by a few folk.  I am building a Z-Axis today and the opportunity came up, as they usually do.  They are very easy to do, once you know how.  My cousin taught me over the phone, which can be a bit difficult.  The hardest part is locking in the secondary thread.  Some people use super glue to lock in the thread.  
 
Most people use metallic thread for the secondary wrap.  The smart builders use wire because it’s much easier to work with.  LOL.  
 
Step 1.  Start the wrap:
 

 
I’m doing alternating wraps on the ferule section.  This wrap is even easier because starting the alternating wrap does not have to be done until you have a good number of wraps.  They can be a bit difficult if the alternating wraps need to start right away.
 
Step 2.  Align the metallic thread perpendicular to the main wraps and tape down.
 

 
Step 3. Wrap over the metallic thread to lock it down:
 

 
This is the hardest part.  Try it and you’ll see what I mean.  I cheated a bit by moving the main thread slightly over to the right on the metallic thread to capture the thread.  I’ll make about 3 wraps this way and then use my burnishing tool to move the main thread to the left, tight against the other main threads.  If you didn’t lay the metallic thread just right, too much of it to the left, it will stick up.  You might want to pull the metallic thread, so it’s underneath the main thread.  This can cause the metallic thread to pull apart and become worthless.  You just need to play with it.
 
Step 4.  Start the alternating wraps:
 

 
There are two key steps here  1st,  make sure the metallic thread goes on the inside of the main thread.  If you’re wrapping to the right, the two thread will be side by side, as in the picture.  The metallic thread should be on the left side (or inside) and the main thread should be on the right.  This will make locking the metallic thread easy at the end of the alternating wraps.  2nd.  Keep the metallic thread tight against the blank.  You may have to pull on the metallic thread a bit.  This makes for a much cleaner wrap.
 
Step 5.  Complete the alternating wraps and lock it down.  
 
 
 
I’ve been making 3 wraps using the alternating wraps.  Keep the metallic thread on the left and the main thread on the right.  At the end of 3 wraps, I slide the metallic thread underneath the main thread to the right and lock it down.  Try to end the alternating wraps at the same blank position as you started.  Makes for a cleaner looking wrap.
 
Step 6.  Continue and complete the wrap as normal.
 
 
 

 
Finish as usual.
 
I’ve been using alternating wraps for the ferule and measuring wraps.  You can use this same locking down method on metallic thread and have a solid metallic wrap.  There are all kinds of different uses of this method.  
 
Thanks,
Chiaki    

Thanks for the tutorial.    I like wire wraps as the wire holds its shape better and can easily be pulled back to line up the start/stop positions of the decorative wrap.
 
Who helped you take those pictures?  I see that as a feat, as how'd you keep tension on the thread and operate the camera at the same time?  Do you have three hands or an elf helper?  

Thanks Chiaki,  
 
I was kicking myself for not writing down how you did this in the last class.
 
~John

Here's my example of alternating wraps:
 

Thanks Chiaki,
Your tutorial alone gained alternating wraps a position on my first rod!!
Cris