I want to layout a closed butt wrap on a bass rod, so that the layout threads for the 1st pattern cross at a specific point on the rod.

I am very familiar with the tapered offset method and have used it for years, but can't figure how to do this one.

Does anybody have a way to do this other than trial and error?

Thanks

Wiltz Ledbetter
Montgomery, Texas

If the taper is slight, and it is likely to be on a bass rod, you may be able to get by without any sort of taper offset layout. It will require that you spread threads at the butt end and pack a little tighter at the tip-most end, but in most cases you can get a fine job this way.

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Assuming that the blank taper is "less than slight", thus forcing the use of tapered offset, do you know of any way to do the layout so that the 1st pattern layout threads cross at a specific place on the blank.

There must be a way, since many of the guys are locating cross-wrap patterns directly under guides.

Thanks

Wiltz

There are various methods. The Clemens book on thread art has at least one or two. I've never bothered and never failed to nicely close in a wrap.

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I determine where the stripp will go, and measure that distance. I'll play around with the spacing in VisuapWrap until one of the numbers matches the distance where my stripper guide is going. I think others who do it just put the stripper guide on top of th e patterns and place the rest of the guides on teh blank accordingly.

Regarding Taper offset Spacing - I get more people asking why my pattern closed on the tip before the bottom of the wrap than anything else - once they use the TOS their problems go away.

Billy I am sorry to be so miss informed but what is the TOS.

Corky
Corky's Custom Rods
Savannah, Georgia

Taper Offset Spacing

If I understand your question, by first cross do you mean the one closest to the tip and do you want to place that at a specific point?

I'm not sure why this would pose a problem, just do your layout spacing from tip to butt instead of butt to tip. If you don't like the calculated placement of your cross closest to the butt (laid out square cross) you can always adjust the spacing a little by compressing or elongating the spacing. But if you compress or elongate off of square, you could just do that from butt to tip and place the tip cross where you want it.

Sorry if I am misunderstanding your question and giving erroneous info - just ignore this then.

Wiltz,

I'm confused, are you trying to locate the pattern on the zero axis running the length of the rod or a specific point on the length of the rod ( example; 25 inches up from the butt on the zero axis)?

In either case just mark the first repeat where you want it and mark the renaming repeats using TOS.

Don

Thanks for the suggestions, guys. Here's some more specifics and an example about what I am struggling with.

Basis: My zero-point (L = 0) for all measurements is at the very tip-end of the foregrip which is already installed on the rod.
Only the 0 - axis is being considered.

I normally allow 25.4 mm for a hook keeper wrap immediately up from the end of the foregrip - before starting the decorative butt wrap. If I were wrapping a simple diamond crosswrap, I would really like for the 1st pattern crossing to occur right at L = 25.4 mm so I could shorten the hook keeper wrap just a bit and show a complete "1st diamond" on the 0 - axis.

Problem is that when you start TOS at L = 0, that first pattern falls at 32.5 mm (close, but just enough to fouls things up a bit). If you start TOS at L = 25.4, the 1st pattern crosses much father up the rod and that won't work at all.

I was hoping that somebody had figured out a way to "back-calculate" TOS from a specific pattern crossing point on the blank, in my case L = 25.4 mm. Based on everyone's input, I think that I have concluded that everyone is doing this by trial and error, in one way or another - and that's okay by me. I was just hoping for something of a more specific method.

I really appreciate everyone's ideas.

Wiltz

Locate the first pattern where you want it at the butt end. On the zero axis the center of the first pattern will be 1/2 of the length of the pattern (determined by calculating the TOS) If the length of the pattern is 32mm, mark the 0 axis 16mm up the blank from the point that you want the pattern to start. Using your TOS calculations lay out the remainder of the wrap. You can't control the exact location where the last repeat ends, the taper of the blank determines that, but you can come close.

Don

Thanks, Don. I appreciate you following up on this.

One last thing. I want to be sure I understand your post. You say to locate the first pattern where I want it (0n the 0 - Axis). That's what I am trying to do.

Then you say that the first pattern will be 1/2 the length of the pattern as determined by TOS. I understand and agree with that, so long as we are talking about the 180 - axis.

Since I have already placed the 1st pattern where I want it on the 0 - axis, don't you mean that the pattern will appear at 1/2 the TOS length - ON THE 180 - AXIS? Using the 32 mm example in your reply, the pattern will repeat at 16 mm, but on the 180 - axis.

I understand and agree that you cannot control exactly where the last pattern will appear at the tip-end of the butt wrap.

I just want to be sure that I am not missing something here.

Thanks

Wiltz

Wiltz,

Despite what others have posted to the contrary, you can in fact locate both the first and last cross points wherever you want on the zero axis (or any other axis for that matter. However doing so you will very likely end up laying them down other than square. This is what I referred to in my first post when I wrote about compressing or elongating the pattern. To compress or elongate a pattern, you figure out a square layout locating one of the end cross points. It sounds like you prefer to locate the cross in front of your grip first. Let's work with that:

Lets call the cross closest to your grip your "first" cross and your cross furthest from the grip to be your "last" cross. Moreover, let's call the cross closest to your "last" cross (and between your first and last cross) "last cross-1". So you check the diameter of your blank and figure out your spacing and take into account your taper. So you have your first cross where you want it and neither your last cross or last cross-1 fall where you want it to. However, chances are one of the two crosses is closer to your desired spot than the other. The trick is to proportionately adjust the spacing of all the crosses either further apart or closer to each other so that either your last cross or last cross-1 falls at your desired location.

Here's an example:
Lets say your first cross needs to be at 21.000" from the butt and your desired last cross location is at 26.500" from the butt. Using your blank diameter you calculate your cross spacing and determine you need 1.5" from center to center. Not taking into account your blank taper to adjust individual cross spacing, you would locate your first cross at 21.000", the second at 22.500", the third at 24.000", fourth at 25.500", and fifth at 27.000". Since we have gone past your desired location at 26.500" you don't need another cross. In this example your 4th cross at 25.500" falls 1.000" short of your desired location of 26.500", and your 5th cross at 27.000" falls 0.500 beyond your desired location of 26.500". One of these two crosses (4th or 5th) will be moved to your desired location. Since the 5th is closer than the 4th, you will probably move the 5th. Moving the 5th in will be a compression scenario, whereas moving the 4th out will be an expansion or elongation scenario. In addition to considering which is closer you should also consider the shape of the pattern. Will it still look okay if I compress/elongate? Will I have enough thread room if I compress? Will I have too much thread room if I elongate? If I'm doing a closed pattern, how will the compression or elongation affect the background that closes the pattern?

Let's assume you're okay with doing a compression and locating your 5th closer at your desired location. That will be our plan. Now, make your taper adjustments for each cross based on your square spacing of 1.5". In our example, let's assume you calculate that you need a .010" adjustment between crosses to compensate for blank taper to do a closed pattern. Since there are four (4) spaces between the five (5) crosses and we need to have them incrementally .010" different, then the space between the first and second cross will be 1.485", between the 2nd and third 1.495", between the third and fourth 1.505", and between the fourth and fifth 1.515". This gives us cross locations of:

Cross 1 - 21.000"
Cross 2 - 22.485" (Cross 1 - 21.000 + Increment 1 - 1.485)
Cross 3 - 23.980" (Cross 2 - 22.485 + Increment 2 - 1.495)
Cross 4 - 25.485" (Cross 3 - 23.980 + Increment 3 - 1.505)
Cross 5 - 27.000" (Cross 4 - 25.485 + Increment 4 - 1.515)

At this point we have calculated a taper-adjusted square layout. Now we have to compress it to locate the last cross on the desired location.

Our total uncompressed layout length is 6.000" (27.000 - 21.000). The compressed length is 5.500" (desired 26.500 - 21.000). Use the formula "uncompressed length" x "compression factor" = "compressed length". To find the compression factor, we can divide each side of our formula by the uncompressed length, so compression factor = compressed length / uncompressed length. The formula to determine a compression factor for an elongation would be the same principle. So, using your numbers, the compression factor = 5.500" / 6.000" or .9167. Note all compression factors will be less than 1.000 and all elongation factors will be greater than 1.000.

Now you will use your first cross position of 21.000", your four taper-layout increments, and your compression (or elongation factor) to calculate your 2nd through last cross positions.

Cross 1 - 21.000"
Cross 2 - 22.361" (cross 1 + (increment 1 x compression factor)), (21.000 + (1.485 x .9167)), (21.000 + 1.361)
Cross 3 - 23.731" (cross 2 + (increment 2 x compression factor)), (22.361 + (1.495 x .9167)), (22.361 + 1.370)
Cross 4 - 25.111" (cross 3 + (increment 3 x compression factor)), (23.731 + (1.505 x .9167)), (23.731 + 1.380)
Cross 5 - 26.500" (cross 4 + (increment 4 x compression factor)), (25.111 + (1.515 x .9167)), (25.111 + 1.389)

There you go. You have the following:

1) Desired starting first cross position
2) Desired ending last cross position
3) Taper adjusted so you can perform a closed wrap if you like.

I hope this was not too boring or confusing, and it helps.

Oh by the way, I calculate my crosses to the nearest .001" and use the sharp inside measuring points of my calipers to scribe my cross points into the blank finish along my axis for very precise cross locations. If I pack and burnish my threads evenly and don't have an imbalance between single and multiple thread bands left/right or up/down, then my closed patterns pretty much close up perfectly every time with very little effort. Once you get the hang of it you can do this very quickly. For me, spending a little time planning saves me a lot of time fighting poorly placed threads later on.

But hey, some guys can just lay down thread comparatively haphazardly and adjust as they work and end up with really nice work, but I think they are few and far between (yeah, I'm enviously looking at you Billy, LOL)



Edited 5 time(s). Last edit at 03/13/2014 04:46PM by John E Powell.

Wiltz Ledbetter Wrote:
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Quote Wiltz; "Then you say that the first pattern will be 1/2 the length of the pattern as determined by TOS".



Wiltz,
I tried to say that the CENTER of the first pattern on the 0 axis will be located up the rod 1/2 the length of the full pattern. In my example the full pattern is 32mm so you will have to start building the first pattern at 16mm (that point will be the middle of the pattern) and build out in both directions so the point of the diamond at the butt end will be at the desired point. That point is 16mm from the center of the pattern.

John, I really appreciate you taking the time that you obviously did to respond to my question.

I had ever considered mixing compressed and elongated spacing within the same wrap. Heck, I have enough trouble keeping up with just one spacing at a time. Absolutely no reason at all that this won't solve the problem, and I am going to try it.

When I started wrapping some 20 years ago, I took initially took the route of "haphazardly" laying down threads, then trying to move threads around on the blank.. That is a big problem, especially when doing closed wraps, which is about all that I do. I am convinced that the best way to get from here to there is to get the spacing right before laying down a single thread. II used to work for a guy that said, "There's never enough time to do something right, but there's always time to do it over."

I am somewhat surprised that you are scribing the crossing points into the blank. That was the preferred method when we were dealing with fiberglass blanks. I just don't do that with graphite blanks. Just a bit too risky for me.

Again, thanks very much for all the detailed work.

Wiltz

Don - That clears it up for me.

Thanks for the follow-up.

Regards,

Wiltz.

Wiltz,

Your not really doing both a compression and elongation at the same time, your doing one or the other to the entire wrap. The shortening of spaces between cross points below the center and lengthening of cross points above the center of the wrap is the method used to equalize the space for threads to fit along the tapered length of the wrap. These are two different steps with similar terminology and concepts, but they should not be confused with each other. Taper-offsetting takes place first, then compression or elongation of the tapered-offset area takes place second. Taper offsetting is a step I did not describe how to perform in my post above. I just provided a number to work with for the example. Determining taper offset spacing is an entire post in itself.

Also, I don't scratch the blank hard enough to damage any fibers, just a light touch to the surface of the finish. I'm in no significant way harming the blank or weakening it. I don't like to mark by hand, it's just not accurate enough for me.

John -

Thanks for the follow-up. I understand what you are saying.

What I was trying to say previously was that, in the past, I have always decided early on whether or not to compress or elongate a pattern that I was preparing to wrap. I just never was prepared mentally to do one or the other in order to achieve some specific end, other than to get close to the desired number of pattern repeats within an approximate length of butt wrap. The concept of either compressing or elongating a pattern to arrive at a specific pattern crossing point is what is a new approach for me.

Years back, in an effort to save time, I spent a bunch of time developing an Excel worksheet based on the TOS method that quickly calculates pattern spacings I just enter a couple of measured blank diameters, desired length of wrap, and compression or elongation factors, if any. The worksheet cranks out pattern spacings on the 0 and 180 axes. Just don't have to do the graphical solution and/or a bunch of manual calculations any more. Let me know if you would like to see the worksheet and I'll send it via separate e-mail.

Wiltz