Need help with Stu's Calculator

[MikeW]

Yes I've done some searching and didn't find my answers. I don't fully understand everything in it. I want to buy some arrows online so they are home waiting on me when I get back home in a couple weeks. I don't have the parts or have scales with me to measure the parts is the first problem, then how do you know the GPI on wood arrows? Unless of course you have them on hand and can weigh them. And I don't understand the footing part.

I've punched some #'s in for carbons and it tells me I need a 340 which I'm having a hard time believing. I'm hoping to pick some arrows where all I have to do is play with the brace height a little or maybe the point weight by a few grains.

If someone who is good at using this thing could punch some #'s for me it would be greatly appreciated.


Here are my specs:
Two recurve bows both 62" inches(neither are in the drop down menu)
One is 53# at 28" the other is 56# at 28" I pull 28 and both are as rated. Both cut 3/16" past center and I use Velcro as a side plate and on the shelve so -1/16 is the number right?
3 5" feathers, 10 strand SBD string.

I want to use Beman MFX as carbons and/or 3 Rivers Trads. I want these to come in around 580-625 grains using 200-300 grain heads. I've used aluminum footing on the MFX's in the past at 1". Am willing to try the new carbon collars for them if that's easier. I really prefer my arrows cut 29" BOP but if I have to go up or down a little am willing to make a change. My hopes are to find a carbon that will shoot out of both bows with just a little tip weight change or nothing at all would be the perfect world.

The next would be woodies for these two bows, Sherwood's 11/32 tapered to 5/16 at the back and get in the same weight range if possible, basically am looking to shoot at least 10.5 to 12 GPI with both carbons & woodies.

TIA
 

[Shawn Leonard]

Well the you can go with .400 spine but if cut to 29"s you will need all of 325 up front out of the 56# bow and it better be a high performance curve at that. If you want to shoot them out of the 53#er you need more weight up front. Never had any luck with Stus calc. It has me way overspined on all my bows, as much as 25-30#s over. Keep them long out of the 53#er and you can shoot the same 325 up front. Just my 2 cents. Shawn

[Butchie]

Unlike Shawn, I have had good success with the calc getting me real close.

3/16" - 1/16" = 2/16" or 1/8".  You may want to check your readings using -1/8".  I would think this would get you real close depending on up front weight.

[Flying Dutchman]

You simply can't know the GPI of woodies on forehand. OR...... you order then in a specific weight range.
For Sitka Spruce it would be typical around the 10 GPI and for POC 11. But since very tree is different, the weight can vary.

Stu is always right on the money for me!

[Prairie Drifter]

I ran your numbers, a .340 should work, cut to 28.75,50gr insert,200gr point. Right between both bows.

[MikeW]

Thx for the help guys am still leery of a .340 It seems to me it would be way too stiff. I think I have some .500's at home that are cut 29" or 29.5"
Am going to bare shaft them with 200-300 grains up front and see what they do. Maybe I'll just do the safe thing an order a shaft test kit.

[Night Wing]

I have a velcro side strike plate, but my velcro is 1/8" (+2/16") thick. Since your bow is cut 3/16" past center (-3/16) like mine are, you might want to put (-1/16) in the Center Cut/Strike Plate Position in Stu's calculator.

[MikeW]

Originally posted by Night Wing:
I have a velcro side strike plate, but my velcro is 1/8" (+2/16") thick. Since your bow is cut 3/16" past center (-3/16) like mine are, you might want to put (-1/16) in the Center Cut/Strike Plate Position in Stu's calculator.

That's what I did.