spine considerations shooting around self bow handle

[Sockrablur]

Hi guys... first a little background. Last year I had a great time creating my first primitive arrows to shoot out of a purchased self bow - shooting around the handle, no shelf cut out. I was so excited to do so any things I had never done... use sinew, make and use pine pitch glue, bone points, Knapp stone and glass... I made arrows I was really proud of but looking back I feel I didn't give spine it's due diligence. Coming from surewood dug fir I introduced to many variables at once... 33" (pre self knocks & point halfting) red Osier dogwood & wild rose shoots weaken spine d/t length, their natural taper make it more forgiving, my bone and glass and obsidian points less than 125 gr stiffen spine.

I know this is a little long and being on the new side it feels complex but what I'm hoping for is so thoughts, conversation, tips on building shafts out of natural shafting with the intention of shooting around a self bow handle... I have good access to red Osier dogwood and wild rose to work with. My natural tendency was to build shafts way to stiff and heavy so I'm using a Don adams spine tester and grain scale to try and be consistent as possible.

Currently I'm shooting a 60" tip to tip elm self bow #55 @ 28
To experiment I'm building (3) 33" dogwood arrows with a spine average of 500, bare shaft weight 530- 560gr I plan to glue on 125gr steel tips. So finish weight pushing an estimated 700gr... still sounds heavy to me!

I've read and understand stiff side of shafting toward bow but sometimes natural shafting has a little bend you can't get rid of. Does anyone consider this while building or ignore it?

If I was going to build Doug fir parallel bought wood shafts what spine would you use for this bow? Are there any generalizations that can be said... how much weaker should the arrow be to go around the handle?

Thanks guys for your thoughts on any piece of this or what works for you. I know the bottom line is what shoots straight out of the bow and I'm looking for that... just thought maybe I could shorten the experimenting with your input. Jim

[Pat B]

When shooting doweled shafting I usually go about 10# lighter spine than draw weight and leave the shafts long; 30" for my 26" draw. With natural shafting like hardwood shoots and cane the natural taper reduces the effective spine by 10# and I also leave them long. For each inch over 28" you can reduce the effective spine by 5# per inch.

[Sockrablur]

Thank you Pat!

[aaron]

you have already taken the most important step towards correct spine by using a grain scale, spine tester, and understanding the effects of tip weight, shaft length, etc. Testing will help you find the right dynamic spine for your bow. In testing, I try to change one variable at a time- for me it's point weight that I fiddle with. Once you have an arrow that seems to fly just right, the next challenge is getting the same flight out of an arrow of a different length, or a different stiffness. You could do the testing all over again, but you don't have to. I use a program called "stu millers dynamic spine calculator" this will let you "virtually" buikd arrows and it will calculate dynamic spine for you.
so, once you know the preferred dynamic spine of your bow, you can match arrows to it using the program. It's not perfect, but it's good enough for me.

[Sockrablur]

Yup... Ok Aaron. I like that thought... Spend the time and effort to make one arrow that is correct. Not 3 or 6 or 12 pretty arrows that are all wrong. I feel a little stupid but honest lol enlightened, ya that sounds better I learned a lot of great skills last year.... but now we go deeper.
Thank you for sharing guys, its much appreciated!

[DC]

I made six identical arrows except for spine weight. Each one is 5# heavier than the last. So 20# to 45#. I shoot light bows. No fletching. When I make a new bow I just grab my test arrows and shoot each one. One of them will go nice and straight. Then I know the spine for that bow.

[Sockrablur]

That's smart DC! Solid tip, thank you.
So I settled on a starting point, a single arrow to try and tune. I took one of the three Red Osier dogwood shoots I had been reducing and cut it from 33" to 31" tapered the larger end for a 125gr steel field tip, the other end I fit  a self knock to my string after orienting the stiff side to what will be the bow. After this and final 220 sanding spine was at 500 and weight 484gr, first coat of finish is drying...




I love a little bark left on them...

[crooketarrow]

 I've found out that most self arrows have a 8 or 9# spin range. Meaning  a 50# bowAnd with a little playing around with lenth and head weights. I hav'nt spinned anything sence I started makeing self arrows.

  I make the arrow to the bow meaning if I'm shooting say 50,55 #'s. I'll likely fall into that 8
or 9 # spine range. That do'nt really make since but thats the best I can exspline it.

  My way been woking for me for 23 years since I first makeing self bows. I made recurves and long bows for 6 years before that.

 If my bow shoots it I use it. Were shooting old slow self bows WERE NOT SHOOTING 300 FPS grains don't matter at 12 yards. Just from readying yuo all I know some of you old times know just what I mean.

[lebhuntfish]

Lots of good info here, I'm watching this one. Patrick

[mikekeswick]

There isn't really any point in leaving your shafts overly long. For a 28 inch draw I would cut them at 29 then fit point cut nock etc. This way you don't need extra meat in the shaft to get the spine up enough for correct flight.
Eg. When cut at 29 for a 55#@28 bow your shafts should spine around 45 - 50lb (dependant on point weight and bow speed). If you left them at 32 then you would need around 60 -65# spine. This means that you have 3 - 4 inches of extra shaft weight and the shaft will have to be thicker to give the stiffer spine. All in all this will give you a heavier shaft with more trajectory to worry about and no gains over a correct length shaft.

[tallpine]

The spine calculators and  rule of thumb does not work on selfbows. At least not for me anyway, too many variables such as arrow pass width and bow efficiency. The best way I have found to tune a self bow is bare shafting. I start with a shaft that I think is pretty close, leave them full length, shoot them. They will probably be weak, I then cut 1/2 inch off at a time until I get them hitting in line with the mark. I then fine tune with point weight. Be aware that you have to have reasonable good form to do this because form errors will affect your results. I shoot them several times to account for this and you can pretty much tell when they are grouping left or right. Left, they are too stiff, heaver point. Right, too weak, cut 1/2 inch off. Go slow and take your time. If you can get your unfletched arrows hitting the mark at 5 yards you have the correct spine. all that's left is to determine your correct nock height. Go slow, this takes a little time This method has always worked well for me, your results may differ.

[Sockrablur]

Guys thank you for the great posts. Understanding spine can be intimidating, your tips and suggestions seem doable and I'm actually excited to try... I've been chasing Turkey's but that ends at the end of this month. I keep you posted on my progress...

[Sockrablur]

Ok guys this is what I built as a start...
[Remember I'm shooting a 55# @ 28" elm self bow with floppy rest.]

Red Osier dogwood shoot hand planned/ sanded reduction to 500 spine/52# @28"
Shaft is cut to 30.5" (end of wood tip taper to throat of self nock) This reduces actual spine to
40# with 125gr steel field point. (Arrow should be at the weak end of range)
3 LW 5" wild Turkey feathers burned down to 3/4" high
After 2 light whipe on  coats of poly, sinew, feathers, fp... finish weight of arrow is 638gr.

Pictures for fun...











You may notice, I placed a single piece of red glider in a drop of glue on top of the side of the self knock to go against the bow. This is the stiff side of the arrow.

[Sockrablur]

So please correct me when I'm wrong or point me in a better direction if you see one as I go. My arrow is drying, I plan to shoot it this evening.

I like what mikekeswich said about cutting off the extra with hard wood shoots. I hope to take more off mine. I have the room to remove 1.5" (35gr) and still have 29" for my 28" draw.

I'm going to use tallpine tune pattern but not bare shaft. I recognize my form and release is not Olympic so I hope to see a recognisable pattern with my feathered shaft.

Ill warm up first, luckily my carbon hunting arrows shoot right where I look with this bow.
I'm expecting a weak arrow so.. shooting right.
Ill cut 1/2" for up to 1.5" then lighten tip weight if necessary.
10yards sound ok?

[Sockrablur]

Well I really wanted the arrow to shoot weak so I could correct it. I took many more group photos and never once even with what felt like a pulled shot did I shoot right, not even a little. The dog wood arrow seemed to fly straight, even more so than the carbon. I would shoot a few carbon till I felt my draw and release was good then shoot the wood arrow. It was a little distracting I cought myself trying to watch the arrow flight rather than focusing on my shot sequence. Ill have to shoot more and see.

I'm tempted to glue on more weight to weaken the shaft and see it's effect on impacted. That would be easy enough to do. I surely not done but what I see says the shaft is not weak. Any thoughts? Constructive criticism? Thanks, Jim