How to measure 300 pounds?

PLEASE HELP TO FUND ARCHERY INTERCHANGE

carl7

New member
OK, ready to build my first string, string and stretching jigs made.

Question: Any rule of thumbs or ways to estimate 300 pounds without using a scale?

I looked at small, digital, luggage scales but don't know how accurate and quality they are. Next is a large hanging scale, probably 8" round face and expensive.

Thought about using a lever and some barbell weight, ie: 50 lb. to equal 300 lb. by means of a lever. Even thought of using the deflection method like how they measure spine. So many pounds to push the string down one inch etc.

Haven't come up with solutions.

Carl
 

Tuck

New member
So why do you need to weigh 300 lbs?

OK, ready to build my first string, string and stretching jigs made.

Question: Any rule of thumbs or ways to estimate 300 pounds without using a scale?

I looked at small, digital, luggage scales but don't know how accurate and quality they are. Next is a large hanging scale, probably 8" round face and expensive.

Thought about using a lever and some barbell weight, ie: 50 lb. to equal 300 lb. by means of a lever. Even thought of using the deflection method like how they measure spine. So many pounds to push the string down one inch etc.

Haven't come up with solutions.

Carl
 

WillS

New member
My lord you are putting way too much thought into string making. You could have made ten strings in the time it's taken you to post all these threads haha!

String making is unbelievably simple - twist two bundles together, wax, brace, serve done. All the stretching, the jigs, the different serving materials, the weight, the power etc is just there to push people into spending more and more money for gadgets. Don't over think it, just get on and make some. I just finished a tillering string for a 120# warbow in my hands, no jig at all because you just don't need one and I'd broken my own one! Stretching happens when you brace anyway so don't fret about finding and measuring stretching devices...!

Honestly, get a couple rough ones under your belt now, forget about all the gadgets and tools because stuff will turn up as you're making them that websites and videos won't mention and you need to learn to deal with issues as they arise. Once you've made a couple, if they're not perfect make a perfect one using your new experience. Go go go!
 

Vagabond

New member
Hmmm, that's about the weight of:
* 3 x lady recurve archers
* 1.5 x gent compound archer

A water butt? 300 pounds = 136 kg = 136 litres of water.
Or 6 x straw bosses @ 23kg each.
Or 1 straw boss at the end of a lever.

A pulley system?

What kind of accuracy do you need? e.g. measuring breaking strain of knicker elastic?

Need more clues on the application i.e. the jig.

V
 

carl7

New member
My lord you are putting way too much thought into string making. You could have made ten strings in the time it's taken you to post all these threads haha!

String making is unbelievably simple - twist two bundles together, wax, brace, serve done. All the stretching, the jigs, the different serving materials, the weight, the power etc is just there to push people into spending more and more money for gadgets. Don't over think it, just get on and make some. I just finished a tillering string for a 120# warbow in my hands, no jig at all because you just don't need one and I'd broken my own one! Stretching happens when you brace anyway so don't fret about finding and measuring stretching devices...!

Honestly, get a couple rough ones under your belt now, forget about all the gadgets and tools because stuff will turn up as you're making them that websites and videos won't mention and you need to learn to deal with issues as they arise. Once you've made a couple, if they're not perfect make a perfect one using your new experience. Go go go!
No WillS, not at all, sorry to disagree but actually I'm not putting enough thought into stringmaking. And, I don't buy pre-made archery gadgets, I try to make everything necessary, that's just me. You see, I was left with a good amount of tools and materials (thanks Dad) and not one to waste things, I'd like to put them to use if possible, besides, I'm a tinkerer.

I'm going along at a good rate, or so I thought! (I started the whole archery thing two months ago).

Hope you somewhat agree!

Carl
 

carl7

New member
Unless I've read and heard it wrong from string mfg's and makers, it's best practice to pre-stretch strings initially to 300 pound of pull tension.

Here's my plan: after the ends are served, transfer the partially made string to the stretching jig and apply the recommended number of twists and stretch up to 300 pounds of tension.

Then, while on the stretch jig, test for nock fit and do/complete the center serving.

Please correct me if I'm wrong, I'm always learning!

Carl
 

WillS

New member
No WillS, not at all, sorry to disagree but actually I'm not putting enough thought into stringmaking. And, I don't buy pre-made archery gadgets, I try to make everything necessary, that's just me. You see, I was left with a good amount of tools and materials (thanks Dad) and not one to waste things, I'd like to put them to use if possible, besides, I'm a tinkerer.
I didn't mean to come across abrupt, but you've made 10 new threads on different aspects of string making recently. String making is very simple, and the best (and really the only way) to actually get to understanding it is just to do it. Make one or two crappy strings and you'll know what not to do and you can crank out strings in 10 minutes. Too much reading and not enough experimenting is a curse, and reading somewhere that 300lb is the "best practice" doesn't mean anything except that the people you've heard it from have heard it from somewhere else, or tried it because they heard it from somewhere else.

I've made strings from B50, Fastflight and even natural linen for bows from 15lb to 120lb. Not once did I pre-stretch the string, use complicated jigs, worry about which brand name I was getting etc. Now that's not to say I'm by ANY means an expert - I'm still learning every time I make one - but it goes some way to show that worrying about every finite detail is a waste of your time. Like I said, you could have made a dozen strings by now, and instead of asking more and more questions you could even be helping somebody else out, giving them experience you've discovered yourself, as compared to using stuff recycled by everybody else.

I hope that makes sense. Again, I'm really not trying to be rude or condescending - I just think there's no substitute for doing. The absolute worst that can possibly happen is you waste one string's worth of material. And you probably will waste some, but I bet it'll go wrong in a way that you've never heard about ;)
 

lbp121

Member
To the best of my knowledge only one commercial system stretches to that level and consists of a screwthread and some distance markers. That I believe is the Little Jon (littlejonarchery.com)
As many of us making successful strings for recurve and compound don't have this item you can safely assume it isn't necessary. To serve under tension is good but why 300lb? Why not 100 or 75?
The main thing with string making is to get even tension on the strands before any servings go on, at the beginning as you wrap the thread onto the jig. I use the Spigarelli jig which is quite good but I can't get 300lb tension on it despite having a screw thread. I have measured tensions up to 100lb and this gives quite a high pitch if you pluck the string.
So I agree with the others, you are thinking too hard on this, the best jig in the world won't make a better string than your experience allows so start string making and keep notes. Some will be better than others. As long as the tension you can apply sounds a lot higher than the string on the bow you probably have enough tension.
As a matter of interest about 6 or 7 of our club members both recurve and compound are using my strings so this advice comes from experience.
 

carl7

New member
To the best of my knowledge only one commercial system stretches to that level and consists of a screwthread and some distance markers. That I believe is the Little Jon (littlejonarchery.com)
As many of us making successful strings for recurve and compound don't have this item you can safely assume it isn't necessary. To serve under tension is good but why 300lb? Why not 100 or 75?
The main thing with string making is to get even tension on the strands before any servings go on, at the beginning as you wrap the thread onto the jig. I use the Spigarelli jig which is quite good but I can't get 300lb tension on it despite having a screw thread. I have measured tensions up to 100lb and this gives quite a high pitch if you pluck the string.
So I agree with the others, you are thinking too hard on this, the best jig in the world won't make a better string than your experience allows so start string making and keep notes. Some will be better than others. As long as the tension you can apply sounds a lot higher than the string on the bow you probably have enough tension.
As a matter of interest about 6 or 7 of our club members both recurve and compound are using my strings so this advice comes from experience.
Some good advice you've given lbp, good question 300, 100, 75? I don't know, but I figure the ones who make the string material has done extensive testing and are in a position to offer it. I don't agree on the notion of "thinking too much" though, especially in the beginning stages of anything one has to find through experiences what works for them, it'll all balance out.

One thing that has dismayed me is I hadn't the slightest idea I was riling some, maybe many folks by asking too many questions, I thought it may help some or at least raise "food for thought" or forum participation but apparently not.

I'll refrain from asking too many questions even though the vast majority of answers has taught me a great deal and I'm forever grateful for that.

Carl
 

lbp121

Member
Questions are good but try this idea, ancient Chinese wisdom.
Tell me and I'll know, show me and I'll understand. Get making strings and the problems you are currently worrying over will change. Some things will be worse than you imagined and others easier. Then you will have the experience to ask the right questions as well as a load of strings!
 

chuffalump

Well-known member
I assume that the only reason to pre-stretch a string is to:

A ) make sure all the strands are nice and even and parallel.
B ) minimize or eliminate stretch while on the bow.

In which case you only need to stretch it with a poundage comfortably bigger than the bow you use it on. From an engineering viewpoint 300lb is obviously arbitrary, any scientifically arrived at value would vary with the string material and the number of strands.
 

lbp121

Member
It does help with a compound to prestretch the string before fitting. This helps in only having to set the bow once, twice at the most and to ensure the peep rotation remains correct without having to return to the bow press after a few shots. If we take our most modest dacron bowstring of B55, 12 strands we have a breaking strain of over 12 x 55lb, 660lb. This will stretch in use and that is easily corrected by adding a few twists to maintain bracing height. It's mainly compounds which have to be set and left since running adjustments in the field are difficult. Many recurve archers wouldn't think twice about a minor string adjustment during a day's shooting.
 

WillS

New member
Just to clarify Carl, nobody is riled or annoyed. I'm certainly not. I just wanted to make the point that you can never know all the answers. Forums are great, but nothing beats getting your hands dirty. Good luck with the strings!
 

Vagabond

New member
...Here's my plan: after the ends are served, transfer the partially made string to the stretching jig and apply the recommended number of twists and stretch up to 300 pounds of tension....
Carl
Yep, compound strings are pre-stretched, but recurve ones typically aren't.
Now, my recurve bowstring has 18 strands. If I were considering pre-stretching this then I would do so BEFORE wrapping it up into 18 strands. So, instead of applying 300 lbs to 18 strands, apply a 20 lbs weight (e.g. a bucket of water) to a single strand. Leave for a week and measure how much it creeps & how much it stretches. Then make string and perhaps leave on bow for another week.

...Then, while on the stretch jig, test for nock fit and do/complete the center serving....
Carl
One tiny weeny bijou-problem-ette with this method: before doing the servings the string must be twisted. Once twisted, it tends to behave like a spring. So much of the 300 lbs would be stretching the spring not the individual strands. On the other hand, if you don't twist the 18 strands there's a good chance it'll break. Each individual strand would break well before 300 lbs (about 50 lbs?) and it's very difficult to get all 18 exactly the same length. So the shorter ones start off taking all the strain, so just a few do the stretching (or breaking). This is exactly why ropes are twisted: to share the strain.

Does makes sense?
Hope it helps.
(PS: I'd hate to be your string)

V
 

Shirt

Well-known member
300 is an arbitrary number that's got no specific use other than for stringmakers to say "mine are tensioned to 300#, yours only to 200#, therefore mine are better".

Lay the string up, serve the endloops, do not twist it, put one end on a hook and something heavy on the other end. The purpose of this is to get the strands to even out under tension, not to stretch it in. In all honesty, I've never really noticed any significant stretch on a recurve string anyway - your brace height might drop slightly in the first day or so, so you put some more twists in and away you go...
 

Nightimer

New member
With a compound the strings and cables are pre-stretched with weight.
Any stretch on a compound string or cable is a major problem which can only be corrected by pressing the bow and stripping it down.
Recurve strings are not usually pre stretches as it is a simple matter on a recurve to put a few twists in to sort things out.
 

carl7

New member
Vagabond, noted the tip on when to stretch, thanks.
Thanks Shirt and Nightimer, I'll be making strings for my compounds too.

Carl
 

0neida

New member
I make strings for my Onieda compounds.

They are kind of a recurve on steroids without going too deep into lever limb bow design.

I make the strings on a simple Sherwood jig. Serve the end loops, then string the bow. leave overnight and recheck bracing height in morning.

Serve the center section on the bow so it's in the right place.

Go and shoot the bugger.

Check again for settling and adjust after a few dozen arrows.

The important thing is to get the tension right on the jig so that all the strands are evenly tensioned. It doesn't matter how much tension as long as it's even.

I can see the point of pre stretching the strings for one of those wheelie bows but 300lbs seems an awful lot. Probably more than your bow will ever exert on the string. Could the string recoil from the stretch and actually shorten in use?
 
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