Mass principle help

[mikekeswick]

I'm making a 62 inch ntn molly type bow. It bends in the handle and has 10 1/2 inch 'levers'.
50lbs @ 26
Reflex deflex limb profile but the tips are level with the handle.
My question is what should the weight be according to the mass principle?

It's made from a small dia. hazel sapling and has been heat treated.....it's 50lb @ 24 at the moment and pretty fast so far.

[blackhawk]

If its a true bend in the handle you should be ~14 ounces when done....and that design can easily go to 31"(if u have enough mass in the working limbs to take it) and still not be close to stacking if done right...sounds like your making something similar to one of my signature bows

[mikekeswick]

Maybe! You'll have to wait and see. 
Cheers for that because it was made from a hazel stave that is only 1 3/8ths wide it won't make it much past 26 without a lot of set. Our hazel makes great flatbows but it really needs to be 2 inches or close wide. So this one was really just an experiment.

[BowEd]

Just getting her close to within 5 to 10 percent of that 14% will please you I bet.1and3/8ths" wide is pretty narrow.Never worked hazel before though.My 63"TTT BL I repaired came in with those low mass numbers at 1and15/16s" wide at fades though,10" levers.Pulling 53#@28.5".That's with a 6" stiff handle.Still flat after shooting.Shooting great and am trying to get a nice deer with it now.Good luck.Should be a good one.

[Del the cat]

I'll be interested to see it as it sounds near beyond the limit.
I bet it'll look great...
Del

[blackhawk]

If you think your design for the wood is to narrow,or if your gonna come in more than 2 ounces less than that then make sure you get that handle bending proper...and also get your levers to flex thru the transition,and make only the last 6-8" stiff...get the levers to bend like you would for a handle in a bend in the handle bow...this will help distribute the stress better,and will tolerate being on the low end of your target mass for the bow...cus now you can subtract and ounce n a half from that 14 if you get em to just bend in the last couple inches of the draw like a bendy handle is supposed too...got it?

[mikekeswick]

Thanks guys.
Thanks for the advice BH. I'm going to try this design again with a better piece of wood, this stave is only so so and not really worth putting much more effort into.
Well it's sanded to 120 now and ready for some final shooting/bedding in. Then a quick stain and finish.