Stu's calculator consistently tells me my setups are very weak spined, but I'm getting good flight and I'm hitting where I'm looking.  Its just frustrating.
Any input?
Ken

QuoteOriginally posted by ken613:
I'm getting good flight and I'm hitting where I'm looking.  
Ken

:D

I come up weak sometimes also. There are so many variables to spine and what affects the spine in which you shoot. Stu's system is a guideline that may help you with a good starting point and to others it may be a perfect fit. As I said I am almost always weak on his chart.

Goshawkin....I know, I know....

Heres my input, if it flies good, and goes where your looking, dont fix it. Guidelines are just that, guidelines, they are not set in stone. They will generally get you close but the end result will be what you find that works best for you.

My current setup is nearly 10 pounds underspined according to Stu's calculator but I can put a group of 4 arrows with 2 fletched shafts and 2 bare shafts in a 2" diameter circle consistantly. So I consider myself tuned no whether or not a calculator says I am in tune.

I use Stu's calculator on my two Blacktails.

With my 42# bow, the setup is spot on. With my 37# bow, the setup is very stiff. Both bows hit what I'm looking at. That's all that matters.

I'm generally 5-8 pounds underspined on the cacultaor as well. No worries, though. My arrows fly well and accurately. I love that calculator....super helpful to get you close and look at things like FOC, weight, speed, etc. also helps compare one arrow set up to another

All this is good to hear...I'm coming in 5-8 lbs under also....just wondering what others' experiences are.
Ken

Just my experience

~2#s under has produced acceptable results
~15#s under has produced improved results
~27-28#'s under has yielded some unsurpassed results

Shoot what you yourself have faith in.

This is all quite interesting. I've used the calculator with great success, spot on with alum arrows. Then tried to get some faster, 209 fps speeds, heh, with carbon -,and they are way over spined with fletches tearing up the beaver rest.  Increased point weight, helped but still seem stiff.

I've only used it with 2 carbon arrow setups and I'm about the same as you guys, ~8 pounds weak on the calc but with great bareshaft tuning results. The second set up I plugged it in to be about ~8 weak and found I was very close to being where I needed to be when I started bareshafting.

i have a couple of widow psax's and they all bare shaft tune about 15# higher than stu's calculator consistently.  there is a form factor input that may help you for future setups.  only you, the bow, and your arrows will determine what is tuned.  make sure all data is put on correctly and precisely to get good results also.  there are a lot of human factors that will influence tune that you just can't get from a computer program.  your bow sounds like it is tuned, just go shoot and have fun!

I was looking into having some wood arrows made for my Black Widow. It's 45@28 I pull back 28" I was told that the calculator came up with 30" Sika spurce 73# shafts with 125gr points and 5" feathers. That's 29#s more then the bow.
I bare shafted a 65# 30" shaft an it was way to stiff.I am just going to stay with my carbon set-up.

Bare shafts are giving you good arrow flight?

Then you are right and the chart, in your instance, is wrong.

It's a guide, not a commandment.  Congrats on the succesful tune!

I think the charts are pretty good as a general guide, but if you you are getting good arrow flight with tight groups shooting where you are looking, the charts don't mean squat!. Stay with the setup that is giving you the best results. Again, the charts are guides but are not gospel.

Listen to what the arrows you are shooting are telling you. Charts have limited use and can be misleading.