Finished composite hickory bow/ pics

[BowEd]

Bub....Beware of what you wish for my friend.......lol.I tell ya that backwards C has to be cured I'm sure of that anyway.

[Stick Bender]

The one you said with the siyas not set back enough will be a slick bow when you get it done ,it should be easier to string for sure , is that maple core ?

[BowEd]

Hickory I think.The other is ironwood and needs to be sinewed yet.

[mikekeswick]

I like your style
That perfect one may be right around the corner....
Seriously though that is a real beauty and i'm interested in how your next ones turn out.

[BowEd]

Yes I should be finishing the one horn bow.It's been curing for over 3 years now.Ought to be cured heh....lol.Some limb tapering outward needs to be done on that one for good tiller.Horn and core got interlocking grooves with hide glue.It's 50.75" NTN and 368 grams.
Seems these sinewed bows need updating.The hickory/horn/sinew bow gained a few pounds.Even though I waited 8 weeks for it to cure before tillering.Tillered it back down to 52.5#'s @ 27.5".Did'nt lose much reflex.Still holding 8" @ rest yet.A 625 grain arrow @ 27.5"gets me in the lower 40's in KE#'s @ 175 fps or a little better while learning to try to get the best out of my release through the machine.Seems to be the best I can get out of it.
Still shoots smooth,quiet,and dead in the hand.Been shooting it most every day for 2.5 months.Put a brain tan leather handle on it now.Going to use it for deer soon.

[Stick Bender]

Like the brain tanned handle nice touch , just curious Ed how much reflex was in that bow prior to putting on the horn & sinew ? Also how much weight did it pick up before retiller ? Hope you can skewer a dear with that sweet bow ! Good luck huntings right around the corner !

[BowEd]

Stick Bender....I'm assuming about the reflex you mean the wood core itself prior to composites going on.None.No reflex at all.No heat treatment either.I took my horn laminatons and heated a curvature into them before glueing them on.Showing back on page 2 I think.After the horn was glued on the bow had 5 and 3/8" reflex.After the sinew cured it had 10" reflex with reverse bracing inducing more reflex.
The bow was finished sinewing April 6th.I tillered it around the 3rd week in June if I remember right.A good 8 weeks for sure.Now being September 12  a good 2.5 months later it gained 2 to 3 pounds in that 2.5 months.I keep things around 50% humidity where it's stored.As I did while the sinew cured and while I tillered it.I feel if truth be told on bows with around 3/16" thick cured sinew on it a good 12 weeks or more is needed to completely cure.Conditions can vary for that number to be a bit different but I'm not too far off.I had to retiller it and I put it to a positive tiller of about 1/8".Weakening the top limb some.I don't need to push the string against the weak limb at all now just after brace for a short bit to get it to that tiller.It is that way right from first bracing now.I think the bow was right on the cusp of the tiller I wanted.
I'll say it on here too that it's been in damp conditions[misting and very foggy] for 6 to 8 hours strung with absolutely no ill affects.Not an absolute strenuous length of time test but for hunting here in my situation it's good enough for me.I really like this bow.Here's some more pics.


I guess I could increase the KE#'s and fps speed to in the 50's and around 190 with that 625 grain arrow by drawing to 30" but I feel satisfied with it and drawing to 30" feels too uncomfortable and different to me for accuracy.

[BowEd]

I've got that wrong I tillered it in the end of May.So in an extra 3 months it gained 2 to 3 pounds.

[Stick Bender]

Ok thanks Ed  just dreaming about someday making one of those that is one tuff durable looking bow bet you that one will last a life time of hunting That's some real talent you have there to get that one built I know your to humble to say that but realy should be proud of that.

[BowEd]

Thanks Ritch but you've got all the skills you need to do this type bow.You already are finding out what thickness of sinew will give what poundage to a bow.The horn poundage info is in the build-a-long.

[BowEd]

Stick Bender....The mass weight of a bow like this compared to it's draw weight is way too high compared to a turkish horn bow.It would be way overbuilt.In self and backed bow comparisons it is comparably normal 17.40 ounces before leather handle.Especially holding the reflex it does which in self and backed bow comparisons it should weigh 22.00 ounces.The fps readings are all true and accurate.The only thing that accounts for this is the reflex it holds.After 6 hours of bracing it does not show an over amount of soft set when unbraced.Less than 1.5" which tells me it is not over stressed.I believe it has cured more to account for that also.

[BowEd]

Got ahold of some graph paper & had pre measured this bow by each inch earlier just as it was tillered and made up this fdc paper.It's a 60" TTT & 58.25" NTN bow.It should say 52.5# @ 27.5".It was measured to 28" @ 53.3# at that time.Close enough for me.I should measure it again.I see I forgot to show the 27" line.No biggie the end result is the same at 28".I corrected it farther along this posting showing efficiency and kenetic energy etc.It's been 2.5 months since these figures were took.It has cured a bit more and is performing a little better because of that.

[DC]

I love your bows Ed, they are beautiful. I have a question about the F/D drawing. Do you know what causes the hump in the F/D graph?

[BowEd]

DC...Because of the reflex the bow is holding the draw weight starts higher per inch then it levels off[I imagine then the composites go to work and length of limbs too] then it begins to go up again as string angle and strain gets higher.The hump is stored energy the bow has.A self bows' fdc line would be more straight line maybe even concave a bit the way I understand it because they do not store as much energy.
I should of done this earlier to find out myself here but after crunching all of the figures this is what I come up with for bow efficiency and the kenetic energy of this arrow.These figures may be skewed a few percentage points one way or the other too but overall pretty close.
Shooting lighter arrows of course reduces this bow's efficiency as with most bows.Looking at Adam Karpowicz's efficiency ratings of his horn bows as a goal to look at this bow hangs in there close to most of them shooting heavier arrows[12/gpp].Hard to believe I know but there it is.Arrows shot below [10/gpp] the shorter horn bows out shoot and take over in efficiency and speed.The slightest difference in figures transfers to a lot in the field.Now pulling this bow to 30" would make up a lot of difference and by the looks of the graph line it is not strained so much it could'nt do that.Really did'nt take all that long to figure out and kinda fun too.Even for this old farmer.First time actually doing this.In the future making more types of bows when I want to check a bow out thoroughly I can with confidence know exactly what I've got.Just another tool in the bow making tool box the way I see it.

[DC]

I made a recurve sometime back and did an F/D curve on it. It had a hump like that but the hump coincided with string lift off. I could understand that, but your bow is past string lift off at brace. I can't understand why the reflex would cause a hump like that. I can understand it causing higher early draw weight but I would have expected an even curve. It's almost like there is an "oil can" in the limb(if you know what I mean?) and it's kind of popping through at that point. I'm buffaloed and I'm rambling, sorry.

I'm taking a closer look and I'm confused. You say 17.6 at 6" of draw which should be 12" on the drawing but the drawing says 18.7. Am I missing something?