Dynamic Spine Calculator (ONLINE)

[DRT]

Lol. I figured I was the bad factor in it. It's just funny how different all this is. With a compound it was simple. The equipment was more complicated but it minimized the human equation. With this stuff the human equation is definitely a key factor.

I'm learning though.

Sent from my SM-J710MN using Tapatalk

[Dry Bones]

Rick, my longbow is the good ASL style no reflex/deflex limb design. Correct +1/8 arrow pass from center.
Sorry It was suppose to read 48# @ 27' on my scale. Which for whatever reason generally shows 3-5# lighter on EVERY bow I scale. I hung a 25# dumbbell from it and it scaled correctly?? To back of point arrow length is 29" String is fast flight and 10 strand I think...

[Dry Bones]

DRT, Welcome to my world/
The reason i wanted away from the compound to some extent was that the mechanical components were complicated be it compound. and it did not take much rough hunting to bump something and not have the exact tune you had.
The traditional type bows are more simple weapon and VERY COMPLEX to learn. But it is all on the shooter.

[RickBarbee]

Calculator page has been update to Stu's newest release.

LINK

Rick

[RickBarbee]

Hey Rick, it always tells me a WAY stiffer spine, and I almost completely quit looking at any of the online spine calculators. Nice Homepage though.

Hey Cody.

After thinking about it, it dawned on me THAT a 100gr brass insert is actually a substantial internal footing also, so I enterd your arrow config taking that into account.

I guess at the insert as being 1" in length, but I think they are longer than that.

Here's your calculation figuring the footing. It's pretty darn close.

Rick

[RickBarbee]

There is a glitch/some bugs in the new calculator arrow selections. I just discovered this.

If you run across the glitch for your arrow selection, you can work around it by selecting "other", then manually entering your arrow specs. If you don't want to do that, there is a link to use the old calculator.

Rick

[Dry Bones]

Rick, I have two different 100 grain brass inserts. One is 1&3/4" the other is 1& 3/8 just was a wider collar at the top. I went to the Archery Shop here in Corsicana and they scaled my new to me Hummingbird. My home scale is off so my bow is 51.5 at 28" and just barely under 48 at my draw.

[RickBarbee]

Cody, here is your bow, and your arrow with the 100gr inserts figured in two different calculators.

Keep in mind, the only footing length to be calculated is that which goes beyond the length of a standard insert. That being the case, I split the 100gr weight up between the insert & the footing to 25 for the insert, and 75 for the footing with a 1.2" length for the footing.

Now, this may not be dead nutz/spot on, but I guarantee it is very close, and shows your arrow to be well withing the acceptable range of dynamic spine for the bow.

You have the correct arrow. You just weren't getting it's specs entered into the calculator correctly.

The bottom line is - run with it. You're good to go.

Rick

[Dry Bones]

It's odd how the two different calculations give some slight variance in Speed and Energy.
Thanks for putting this together.

[RickBarbee]

It's odd how the two different calculations give some slight variance in Speed and Energy.
Thanks for putting this together.

Stu did some tweaking on the new version to get it to be a bit more accurate.
Not enough difference to worry about though.

Now we just need to figure out what is keeping it from being web friendly.

This has been one of the toughest projects I have ever dove into.
The good thing is, I at least have one version up & running.
I'll get the new one working like it should eventually.

Rick

[KenWood]

Can't get it to work for me. If someone can I'd like to see what it says.

Sarrels Blueridge sr 52@ 29.5"
Cut to center with probably 1/16" Velcro
Gold tip trad classic 400
78 grain insert
125 grain point
13 grain nock
5" feathers (3)
Arrow length 31.5"

I'm betting it says weak. All other calculators do. It will bust a fletched arrow's nock with a bareshaft though.

[RickBarbee]

Can't get it to work for me. If someone can I'd like to see what it says.

Sarrels Blueridge sr 52@ 29.5"
Cut to center with probably 1/16" Velcro
Gold tip trad classic 400
78 grain insert
125 grain point
13 grain nock
5" feathers (3)
Arrow length 31.5"

I'm betting it says weak. All other calculators do. It will bust a fletched arrow's nock with a bareshaft though.

Not enough info there to work with.

Need to know the shaft gpi.
Need to know the shaft diameter
Need to know the length of the insert.

With what you listed, plus those things, I can probably run your numbers for you. Without those things it's a no can do.

Rick

[DRT]

Rick that's just too much to deal with. If I have to deal with a digital micrometers and scale in grains for every bow and arrow combination I deal with that sucks. I never have to do that with a compound. It cannot be that complicated?

[RickBarbee]

Rick that's just too much to deal with. If I have to deal with a digital micrometers and scale in grains for every bow and arrow combination I deal with that sucks. I never have to do that with a compound. It cannot be that complicated?

That particular arrow isn't in the data for the calculator, and that's why I need the info. I'll enter it as a carbon/other, then enter it's specs.

No, it isn't complicated, but it is precise.
You can't guess at values, and expect to have good results.

It's not that hard to find out the specs on the arrows you use, but I'm not going to do it for you.

Rick

[DRT]

Well I can say you are right in that. I really need to measure my bows at my DL.