Add thread length calculator to normal pattern generator (generator improvement suggestion)
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Floqui
Professional
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4 years, 7 months ago by Floqui
[Disclaimer I use metric bellow but it is not needed for understanding what I am doing]I was making #54661 and started with 26 thread of same length (about 1m). After knotting 60 rows (which is the length of this template) I end up using up all the C colored threads while the A ones have still about 70cm left. So I look at the pattern and make some math and measurements. I end up with results that could be added to the generator in order to have an estimation of how long each of your string should be. (It may be also relevant for the alpha generator but it is less precise as lot of thread is used when jumping from one knot to the other across the bracelet and you may decide to use more than one string of each color to avoid these jumps... but it is another topic) So the following is for A) developer of the app/web page so they can add a functionality to the generator, B) people willing to save cotton, C) people interested in math Note that any normal pattern has a even number of strings that I will note n (in #54661 n=26) and an even number of row noted l (in #54661 l=60) There is 3 different option for a thread: be used to make a knot (k) (I will assume that the length of string used for any kind of knot is about the same), to be a base string for a knot (u), or pass along the border (b) in a pattern the total number of knots is l/2*(n-1)*l/2 and the same for being a base string (as every knot is over a base string) there is also l border (1 of each side of each even row) Now following a string you can count the knot, base string and border as example in #54661 the first B string on the left make 43 knot is base string 4 times and bounce 13 times on the border while the first A string on the left make 1 knot, 52 base and 7 border (you can check that the string is used in every row as 43 + 4 + 13 = 60 = l same for 1 + 52 + 7) using k at the length for the knot, u for being a base string and b a border, the length of the string used in the pattern is then for the first B : l_B = 43k + 4u +13b the first A : l_A = 1k + 52u +7b and C: I_C = 60k +0u +0b now the last step to get the length to be cut for each thread is to know the values of k, u and b. Of course this depend of the diameter of your cotton (if you use 4mm instead of 2mm the full bracelet will be twice bigger and you will have used twice as much string. It also depend of how tight you make your knots but after measuring all the bracelets I had at hand the result are the following: 1) u and b have the same length 2) u (and b) are about the diameter of the string. If d is the diameter of the string u=1.25d (in my realisation of the #54661 d=1.6mm and u=2mm) 3) in a knot you make 2 turn around the base string, so you expect k to be u + 2pi*d ~7.5d In the formula I have neglected the fact that the string pass over itself during the knot and measurements agree that the value should rather be around 8.8 so I have k=8.8*d and u=b=1.25d For my bracelet I have b=1.6mm, u=b=2mm and k = 14mm thus the length I need for my strings are l_A= 1k + 52u +7b = 132mm = 13cm l_B=43k + 4u +13b=636mm = 63cm I_C=60k=840mm=84cm As I have cut 1m string and keep 15cm at the beginning for tying the bracelet this is compatible with the fact I have no more C but 70cm of A ---- Now that we have the math turn to the normal generator: when viewing the pattern one could add 2 fields, one for the diameter of the string (d) and the other for the number of repetition of the pattern. The generator could then compute the total length for each string and display it. Knowing d one can compute k,u,b. In the generator it is easy to compute the numbers of knot, be used as base string or border (#k,#u,#b) for for each string. One can then compute the length of each string for making once the pattern. Then to get the total length one need to add up string length taking into account that the string of same color may be mixed in the pattern I really would like to see this feature being implemented.... |
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2006_Mandy
Bracelet King
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4 years, 7 months ago by 2006_Mandy
Yeah but some people might like to make their bracelet smaller than others might and so the amount of string will vary amongst the people using the pattern therefore this feature wouldn’t be too beneficial. Calculating string length gets pretty easy one you start making bracelets often and can see how much string you will need and if you have too little string you can always add in more.
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Floqui
Professional
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4 years, 7 months ago by Floqui
@Admin ?
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Elise64
Bracelet King
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4 years, 6 months ago by Elise64
@2006_Mandy well it would be helpful because you can make sure you won’t run out in the middle of the bracelet. And also, even if some people make their bracelets smaller, they can make sure they at least have enough like for a normal pattern it would be how much you need for one pattern and same for alphas, and it’s good to have leftover string for small parts of alphas
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2006_Mandy
Bracelet King
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4 years, 6 months ago by 2006_Mandy
@Elise64 well people make their bracelets different lengths therefore the length of string is always going to vary. Plus there really wouldn’t be a way that would be able to calculate the string length. But I mean a video on string lengths might be helpful but over all it’s not bad to have too much string or add in more string while making it. Basically a formula for thread length would need to be created. But anyways I don’t really think there is a possible way to create this feature for many reasons. I might make a forum post asking people how they calculate their thread amount. My other point is a bracelet will need more or less string depending on the start and end if it’s a loop it will need a different length of string than a bracelet with a tie, etc. good day!
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Elise64
Bracelet King
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4 years, 6 months ago by Elise64
@2006_Mandy @Magaron actually did make a video on that! I didn’t watch it but I’m going to sometime.
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2006_Mandy
Bracelet King
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4 years, 6 months ago by 2006_Mandy
@Elise64 really? That’s good news I’ll have to watch it some time
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