Hello,

This week I'm working on my first 4-axis star (or spider).

When it comes to figuring out spacing for the layout "box", is there a formula or do you folks just eyeball it?

Appreciate any tips, my distance between centers is 1.5"

-chad

Well,

A good rule of thumb to follow is 4 threads per mm, so determine how many threads you plan to use to fill the box and divide by 4. This will get you close enough to keep packing and/or adjusting to a minimum.

Hi John,

Thanks for your reply.

I asked the question because I have never done a 4-axis layout and don't want the pattern to wrap too far around the blank.

I understand how to figure out the spacing for each center cross, but what I don't understand is:

How far apart should I place the marks for the box "corners" on each side of the center cross, given that the distance between centers is 1.5"?

-chad

Chad,

I believe I understood and answered your question.

How many threads will be used to form each leg of the spider in the +1 section? How ever many threads, divide the number of threads you plan to use by four and set the cross that many mm from the center. For instance, if you are going to use 5 threads to form each leg (the pattern threads which form the width of the leg, not the length of the leg built up from the +1 background threads), then the box cross layout position will be approximately 1.25mm (5/4) further away from the center of the pattern.

So if I understand,

4 size "A" threads approximate 1mm.

A suitable width in mm for each leg is determined, then that number is divided by 4 and the resulting measurement used to set my box cross layout on each side of the center cross.

Correct?

-chad



Edited 1 time(s). Last edit at 01/05/2015 04:36PM by Chad Barlongo.

Chad Barlongo Wrote:
-------------------------------------------------------
> So if I understand,
>
> 4 size "A" threads approximate 1mm.
>
> A suitable width in mm for each leg is determined,
> then that number is divided by 4 and the resulting
> measurement used to set my box cross layout on
> each side of the center cross.
>
> Correct?
>
Chad, you still don't quite have it right, let me try restating it this way:

What I described was changing number of threads to mm, that is division: # of threads planned / 4 = mm of layout needed.
You can also determine how many threads will fill a given space, that is multiplication: mm of space to fill x 4 = # of threads to fill space.

What you summarized (what I quoted) is not what I described in any reply post I made.

John,

Thank you, I think I understand better now.

What happened was that I read "4 threads per mm" as "4 threads = mm"

Which led me to interpret the number of passes planned in mm (measured), instead of the thread count.

My original question would have been better stated as:

How does one plan the number of threads needed, such that the pattern does not wrap too far around the blank? Is there a formula, or does it just come with skill and experience?

-chad

Chad,

This is what I do:

I count all the threads that complete a pattern including background threads up until the pattern ends. I do not count background threads beyond the last pattern thread. I divide this number by 4 to convert it to mm. So, if I have 40 total pattern threads, 40 threads divided by 4 threads per mm = 10mm.

I then fire up my CAD software and draw a square with side lengths = to the calculated measurement (or you could just measure and draw by hand). I add two diagonal lines drawn from opposite corners of the square to locate the center of the square. Once completed, I use the copy command to copy the square and center marks to make three squares total. I'll need three squares for a simple two axis layout. The squares will represent the area of the pattern. I print out the squares making sure that I set my printer settings to a 1:1 printout to assure they are not scaled up or down in size when printed.

Cut out the squares. Mark two centers on the top axis and the midpoint center on the bottom axis. Turn each square 45 degrees so they are oriented to a diamond shape, and using clear tape, place each diamond on the blank so the center mark printed on the paper is directly over each layout mark and tape them in place. By placing the three adjacent diamonds you should get a fairly good estimation of how much room your pattern will require, how far it will begin to wrap around towards the sides, how much fill you might need to close a pattern, and whether or not you may want to consider contrasting color threads in your fill area to create frames around your patterns.

I've actually printed out permanent sets of diamonds on transparencies that I use with a customer. They come in real handy when you have to help a customer understand why you can't fit a large pattern on a small blank. We'll come to consensus on an appropriate pattern size and this will tell me how many threads I have to work with. So if we decide on a 10mm pattern, i know I'll need a total of about 40 threads +/- for one sided patterns like simple chevrons, or 20 or so to a side on 2 sided box layout patterns.

I'll use the info in this way - say they want a pattern in a metallic (or combo of colors) and the background to shade from light to dark in a contrasting palette of colors. The pattern will probably be pretty straightforward as to what colors go where, but for the background shade I know I'll have to use five colors at 4 threads per color (in a 1 -2 - 1 ) shading pattern to give me 20 threads. It really helps both me and the client a lot to know, for instance, I'm going to need a yellow, bright orange, dark orange, bright red, dark red for the shade, we can pick the colors and set them up next to each other.

Some people know exactly what colors they want and some people have no clue what looks good. This is a great way to approach color selection with the people that have no clue.

If you're going to wrap more than a few dec wraps, coming up with a more permanent set on transparencies is the way to go. You can buy transparency stock for both laser and inkjet printers at office supply stores or online. Once you use these a few times, you'll get an intuition of just how many threads will be required for a given task, but they will still be helpful when working with other people you might build rods for. I use these with my students; it helps them quickly understand how to plan for and get the results they planned for the first time. They get the hang of it quickly.



Edited 3 time(s). Last edit at 01/07/2015 12:43PM by John E Powell.

John,

Thank you very much for such a detailed explanation w/examples of how your method helps both customers and students.

It all makes sense to me now.

I like that by using various templates (sized to each pattern's thread count), one can immediately reference how a pattern might look on a given blank.

I'm off to raid my wife's art supplies for material to make a set of adjacent diamonds...:)

-chad

[www.rodbuilding.org]

I only had regular sketch paper on hand so looks a bit rough, but it did help me grasp the concept.

This is a 15mm pattern, (60 threads divided by 4=15), 0 and 90 degree axes shown.

-chad

Chad,


Rodgeek's blank? Looks nice.

That's the right idea for a 4-axis wrap. I can't see the other side opposite the pair facing the camera. What you would have on the opposite side is the same as what you have facing the camera (though it's certainly not necessary to add them as long as you understand where they would go)

See how nice that works? Now, as long as you pack your threads to about 4/mm, you'll have about 30 threads +/- to a side to work with.

If you're using Madeira 40 you shouldn't have too much difficulty with 4/mm. Use bands of multiple threads where you can as you'll have fewer interlaces which will be easier to move. Wrap single threads where you have to. If you use size A threads, it's going to be challenging to pack 4/mm. I find I get about 15 threads per 4/mm or about 3.75/mm. Figure about 56 threads total, or 28 per side, packed using size A.

Keep in mind that factors like thread tension you prefer, wrapping in bands vs single threads, the quality of functionality of your packing tool and the time and effort you put into packing will ultimately determine just how many threads you can actually fit in that area.



Edited 2 time(s). Last edit at 01/08/2015 12:30PM by John E Powell.