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Main Boards => The Bowyer's Bench => Topic started by: Krasus on February 08, 2017, 11:49:00 PM

Title: Poundage ratios
Post by: Krasus on February 08, 2017, 11:49:00 PM
Just how accurate is the excel spreadsheet thats on tradegang for calculating the total stack adjustments ( to clone a bow but change the poundage )? I also thought about just doing a standard  ratio equation but the numbers seem just to high. Thoughts?
Title: Re: Poundage ratios
Post by: mikkekeswick on February 09, 2017, 02:53:00 AM
I've used the Stack Calculator a few times and it has always been correct.
Title: Re: Poundage ratios
Post by: Mad Max on February 09, 2017, 06:47:00 AM
seems to work good for me.
Title: Re: Poundage ratios
Post by: KenH on February 09, 2017, 09:05:00 AM
Works great for me too.   I build a Prototype shape with a single 1/4" or thinner pine lam, and finish it out just enough to a decent string on it, and a draw weight taken at 28".   Usually the prototype costs me about $40 (two strips of the cheapest fiberglass, some epoxy, and a slice of clear pine).

That gives me everything I need to calculate the correct stack thicknesses for various weights of bows of that shape using pretty woods.
Title: Re: Poundage ratios
Post by: Krasus on February 09, 2017, 10:34:00 AM
Awsome. Thanks
Title: Re: Poundage ratios
Post by: Wagstaff on February 09, 2017, 01:31:00 PM
It works in a limited way..

For instance.. If you are changing your stack of core lams only, yes its fine.  If you are comparing a stack and stepping up or down in glass thickness, the changes are more dramatic than it will predict.!  YMMV