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String making

5K views 21 replies 10 participants last post by  tpcollins 
#1 ·
So, I'm finding that my endless loop strings are shorter after they are served than when I laid up the strands on the jig. When I lay the strands to the spec of the bow , say 38.5,'' then serve the entire string, as Mission does it's stings and cables, the string is shorter than 38.5," by at least 1/4". a) does it matter and b) are others having the same outcome and what are you dealing with it?
 
#2 ·
I assume that your layout length generally allows for tension, twisting, stretching time, and tensioning again while serving.

a.) Unless the 1/4" stretches out during a shoot-in period, it could have an impact on the limb stresses. Would it matter? IDK I would think that it depends on the bow.

b.) How I would handle it, add a 1/4" to your layout length at the beginning to account for this. Part of the process on knowing what to do to create spec strings.
 
#7 ·
Short strings and cables with less twists tend to cause servings to slip imo. All of the strings I have got from 60X have servings sliping do to lack of twists imo. Servings get tighter as the string is twisted. I've never had a problem advancing cams with the correct string length. I've never had a string stretch so far it couldn't be corrected with twists either. jmo
 
#6 ·
Since this is a string subject, I will toss in a question. I recently bought a string/cable set from a company that had never built strings for the Sub-1XR. I gave them the lengths and they sent me the product. Looks good but haven't installed yet. Noticed that the strings center serving has not been double served. So, the serving as is measured .130" and serving on old string measures .165". What problem could I have if I shot with the smaller diameter serving?
I have published this on Mission cite also.
 
#11 · (Edited)
Here’s my video. The string is twisted CCW, the orange “serving” is CW. As I add additional CCW twists to the string, the ends of the orange start closing together and the one on the right catches up and goes past the other one after a few twists - and is tightening.

I had seen a Randy Ulmer clip years ago before I ever got a crossbow, and he stated you should see which way your bow wants to impart spin on a bare shaft at a short distance. My PSE put CCW spin on a bare shaft. All my arrows were fletched RW which rotated the shaft CW. I reflected 4 arrows LW, and they grouped better than the 4 RW arrows. I stripped every arrow and reflected them LW.

When I got into crossbows I found that all my crossbows imparted CW spin on a bare shaft. Later I found out that serving applied CCW will impart a CW rotation on a bare shaft. I posted that on CT and people laughed. Huntingster joined the conversation and confirmed what I said was correct. The crowd went silent.

Since all my Tapps that I do myself or get from Jerry is fletched with a RH offset, this imparts CW spin on a bare shaft - and is the same direction CCW serving imparts on the bare shaft as well.

Contrary to some of the so called string experts, I would prefer a CW string with CCW center serving - to me it looks like it should be served that way anyway. If I ever have to add a twist in the future - I will be tightening the serving instead of loosening it.

I’m pretty sure Boo serves opposite of the so called “norm” as well - at least that’s what his video looks like to me.

 
#16 ·
Here’s what you told me:

"You are going by standing behind the string while serving.

If starting from the right side facing the string clockwise will be coming towards your body and over the string. From the left side away from your body and over the string”.

That seems to be the opposite from this video. Only one is correct. The serving portion starts at about 29 seconds.

 
#17 ·
Here’s what you told me:

"You are going by standing behind the string while serving.

If starting from the right side facing the string clockwise will be coming towards your body and over the string. From the left side away from your body and over the string”.

That seems to be the opposite from this video. Only one is correct. The serving portion starts at about 29 seconds.

That is exactly what the illustration shown says. Quit looking down the string and stand behind it.
 
#20 ·
All I’d like to know is whether the method you described above is the same as the illustration in the video?

It’s a simple question.
.
 
#21 ·
Hey guys,...you want the serving ( all serving ) but especially the knock serving to get tighter as you twist the string to shorten it due to creep. The way I do it is I look at the string from the end ( either end, it’s the same ). If the string is rotating to the right ( right hand helical or right hand thread ) the serving has to be installed in the same direction (right hand helical ) Therefore when the string is twisted to shorten it, the serving will be tightened as well.
I think where a lot of confusion takes place is when we talk of twisting the string in a certain direction....say to the left or counter-clockwise, we are actually putting a right or clockwise look ( helical winding ) to the string.
In Tim’s video, as he states...the string is twisted CCW and the orange serving is CW. While the string “IS” Twisted CCW, it puts a CW helical winding to the string. Tim then installs the orange serving CW which is actually the same as the string.
There you go.....clear as mud.
Lloyd;)
 
#22 ·
I think strings should be looked at by what was done to get them twisted that way to begin with.

I agree - a CCW twisted string \\\\\ with a CW serving \\\\\ looks like they go in the same direction to me.

I didn’t invent the descriptions, I just use what others say they are (serving direction). But CW serving on a CCW twisted string will get tighter when more twists are added to the string.

The odd part may be that serving can be laid down CW for example going from left to right or right to left - just depends whether you wind over the top going away or coming towards you.:ROFLMAO:
 
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