I need to tap into the knowledge base here on TG. I have a 56" Shrew Classic Hunter 57# @29", at my draw (27") it scales out at 51#. Brace Height is 7.25", Nock Height is ½" . I'm shooting CE150's cut to 29.5", 3-5" feathers, 145gr Field Point, and 100gr brass insert. When I shoot I notice the arrows travel in a clockwise cork screw path towards the target. What can I do to correct the flight path? Thanks George
Sounds like both nock high and to much or to little spine. Lots of folks will chime in with good suggestions. I would bare shaft to fletch tune and make sure my nock point height is correct. Then start working on spine for the arrows.
Is the arrow hitting where you're aiming? If it is, then I would suspect it's nock point as well. May be high, or too low, in which case the arrow is glancing off the arrow shelf as it passes.
I don't know much about carbons, but when I get that kind of flight with woodies, if it isn't the nock point, it's usually an arrow that's too stiff for my bow.
How tight does the nock fit the string? To tight will make that happen as well. Mark
Mater the nock is pretty tight I'll shave them down a bit it the morning and see what happens.
Thanks for the input guys I will play with the nock height as well, the arrows are flying pretty close to where I'm aiming, but I have noticed a funny sound when I release it might be the arrow glancing off the self.
When I shot the 150's prior to going back to wood, I had pretty much the same upfront as you with 4#'s more draw weight and had problems with them being too stiff. I had to go to 30 1/2" with my setup for straight shooting.
George
I plugged your info into Stu's Calc and that arrow set up is way weak in Dyna spine. The arrow is at 39.3# and your bow is at 50.8#. What is the center shot on the bow. I used +1/8". If you get rid of the 100 gr insert and go to a 50 you are at 47.9#. Using a CX insert puts you at 55.8#.
You could go with a 50 gr insert and shorten your shafts to around 29" to get a BOP of around 29.375" and it spines at 50.6".
Mike
I think MSwickard is right. I also think the shrew is 1/8" - 3/16" from center. I think you are about 8-10# weak. Try a 100 point for a start. That is if your form is correct. There are many factors.
I shot a CH last weekend. The bow and arrow plugged into the calculator just happens to be almost perfect with a .5# difference with 3/16" figured in. I just checked it now to see, and I am not surprised because it shot like it was very well tuned.
A bare shaft would tell you a lot. You could be weak and have a nock point issue. It could also be form.
You do a good job of telling us all the important information, thank you. I have experience with the Heritage CX150's. I did not have good luck bare shaft tuning (or fletched) these shafts. I am of the opinion they are weaker than their spine indicates or at least they recover that way. Just for experimentation sake, try removing the 100 grain brass insert and use the aluminum inserts they provide with the shafts. This will increase your dynamic spine. Also, if you are drawing 27" you don't need a shaft cut 29.5" long, try cutting two to 28.5" & 28" and see what that does for you. You have many tools to work with. If you still have a bare shaft, try shooting that with varying tip weights and the aluminum insert (or brass) to see how that changes things (I hot glue my inserts into carbons for this reason). Then of course, you can still go back to your brace height and nock height adjustments. As always with tuning, only change one thing at a time so you know how that affects things. It sounds like you are after a high(er) FOC shaft (that's good), the CX150 with the setup you've provided may not cut it. Try a stiffer shaft if you can. Buy one of those tuning packages from 3 Rivers which provide carbon shafts in a range of spines. Pages could be written about tuning. A good read here from O.L. Adcock on tuning. http://bowmaker.net/tuning.htm Keep tinkering and pay attention to how things react with each single change. You are looking for trends.
Good luck!
Kris
From my experience with CX heritage and numerous posts here you are in the # range where you will find people using both 150 and 250's all tweaked differently. I once tried the 150's when I first started out and could not for the life of me get them to shoot correctly from my bow. Now 2 years later and much better form and release I can tune a 150 into my bow.
Thanks for the input guys I raised the nock a bit and had better flight with the 150's, but decided to stick with the 250's I was originally using. I also had to take the leather grip off the bow as it was starting to spin and was making contact with the arrows.