Is there a special formula for spacing when doing a butt wrap? It seems like every time that I do one the thread slips. I do use a underwrap first so the thread will have something to hang on to. I purchased a dvd on butt wraps and it stated to space the diamonds (if you are doing diamonds) the length of the circumference of the blank. Is this so? As always I appreciated all the help that I receive here on this board.

Madfish Rods

That's about right. What do you mean teh threads slip. They aint gonna stay put, you gotta pack them toghther after a few passes

In regards to spacing. Are you referring to a reversed taper offset layout? Not sure if it would help with threads slipping but it allows for designs to not be misproportioned to each other

You can make your spacing whatever you think looks good. If your centers are too far apart, you may have trouble with the thread slipping off the centers if you use much if any tension. You may want to try shortening that length a bit and see if it helps. Wraps where the centers are compressed are a bit easier, in my opinion, to keep the thread tension up and still keep the threads from slipping off the centers. Of course, I hardly ever did them that way - I like the look of elongated spacing.

Now here's something else you can do - when you're wrapping threads that are the same color, wrap them in bands or at least all of one color on one side before starting any from the opposite side. This makes it easier for them to lay on each other where they cross. The result is less slipping.


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Edited 1 time(s). Last edit at 08/25/2005 10:51PM by Tom Kirkman.

Did I hear somebody say, "FORMULA"? To form a 90 degree angle at the intersection of the criss-crosses in a diamond wrap, space centers at one circumference apart:

DELTA = PI x OD = CIRCUMFERENCE [PI = "pi" = 3.14159...]

In other words: Distance (spacing) = 3.14 x blank diameter.

I wish I knew how to do the proof of this by rigorous geometry, but I don't (yet). A fishing buddy of mine who is a bit of a math expert and interested in topology (the study of the surfaces of 3-dimensional objects) said as much once, but we never got around to why. ... Every diamond wrap that I have examined at the RBO Photo Gallery that looks like it has 90 degree angles has a spacing distance that is very close to that value, 3.0 to 3.2 times the blank diameter. Of course, if there is an underwrap, that may add about 0.020 inches to the blank's OD, or another 0.060 inches (1 / 16th inch) to the spacing distance.

Such accuracy in spacing probably only matters in a closed wrap, or in multi-axis wraps. To keep track of all that, there is VISUAL-WRAP. Ask Billy Vivona about that, or go to the RBO Sponsor Links at left.

Best Wishes, -Cliff Hall, Gainesville, FL-USA+++

If you're doing an open type diamond wrap, and want a square pattern, the measured cirumfrence of the blank should be your spacing between crossover points (thats what the books taught me). But keep in mind that there aren't any "rules" for this stuff. When doing open wraps, I make life easier on myself by just spacing the patterns with numbers that are easy to work with like 20mm, 40mm, or 60mm spacing......as far as thread slipping, use the above mentioned tips, and think "It takes thread to hold down thread."

Nobody will notice or care if your diamond isn't square!!

Hi Cliff,
I can't give you a mathematical proof as to why one circumference spacing equals 90 degs crossing, however can explain it visually (well in words actually, but attempting to paint a word picture).

Think of a square. If you draw lines between each set of diagonal corners, they cross in the centre at 90 degrees. (If you start with a rectangle, they cross at a different angle).

Roll up a piece of paper so you have a tube with no overlap. That is your blank. Unwrap the paper and lay it out flat. The length of the edge that used to be curved is one circumference. If that edge was the side of a square, then the width of the square would have to be the same length, i.e. one circumference as well.

Think of the lines drawn in the image above as threads wrapped around the rod. They cross at 90 degrees if the spacing is one circumference. When you butt two or more squares up against each other, the centres of the squares are separated by the length of one side.....which is one circumference.

Butting the squares up against each other is like having your pattern repeat as it goes up the rod. That is how vizwrap does its stuff.

It is a lot easier to demonstrate this than describe it, but I hope that helps.


Dave Boyle
www.visualwrap.com

DAve - I found a new use for Visualwrap teh other day - print out the wrap, size it to teh blank. When you get the pattern teh size you want without wrapping around the blank too much - cut it out. Tape it to teh blank in a spot that will not be part of the wrap, basically add another repeat for this at teh tip or butt depending on the direction you wrap. When you come off the tape, just "hit" teh spot on teh VW pattern on teh blank - that's how you find how far to space layout threads apart.

I used this on a wrap where "BILLY 40" was the pattern. I had no idea how far to space anything apart, but that helped a lot. I'll have pictures of this when I re-wrap the pattern.

Cliff - regarding math & wraps - you do not need to be 1000% precise when doing closed wraps. Use standard taper offset spacing, and manipulate threads to make everythign fit. Color selection helps close wraps too. I have a ton of formulas I use for my wraps, but tehy are not neccesary & in most cases overkill. For me, I have the formulas set up, so I use them - I never have problems.

Billy & Dave - Thanks for the extra insight. I took a tube of gift-wrapping paper (OD = 2.0 inches) and tried it . You guys are totally right on - it works just like you said. When you draw a square diamond on a piece of paper that is cut to perfectly fit (in either orientation) around the tube's circumference - BINGO! The length of the diagonals inside the square (the spacing between diamond centers) is always EXACTLY equal to the circumference of the tube (rod blank). Very cool !!!

For a tube OD = 2.0 inches,
DELTA = PI x OD = 6.28" .
S = 4.44 inches
The side (S) of the square formed can be found by Pythagorean Theorem:
S = square-root of [ 2 x the square of (PI x OD / 2) ].

As all have said, if you want to change (elongate or compress) the diamond's angles, that can be done to a satisfying effect as well. Thanks, Brad for Posting such an interesting and useful question. Wahoo ! Cliff Hall, Gainesville, FL+++

Cliff - if you really want to go into over-detail - there is a way to size a pattern on the blank before wrapping any thread. And you cna put your calculator & protractor to work as well, we see it's been collecting dust since the Spinning Concept threads, lol.

I used to use the Pythagoream Theorem to find out how far to space the layout threads apart. Then I found out it didn't really matter much, as long as I was close I could move threads around to get everything to close & such.

Billy,

In my mind the ideal setup would be to size the pattern according to the taper of the rod (true-to-size), print out the layout threads onto transparent decal paper, apply the decal to the rod, then wrap right over the top of it, like tracing. The ultimate cheat!

Next best method (and more practical) is to print out the pattern true-to-size, then hold the printed pattern against the blank and mark off centres with a marker of some sort. There are some photos of this method on the website [www.visualwrap.com] It's easy and quick to do.

Sounds like your way works too, that's great. It's all good stuff.

Dave

I like the string method in Tom's book. It's easy and I'm making some of the best wraps I've ever done. I wish I would hav thought of it.

Randy