4th bow in the works, 1st r/d all wood.

[DelawareDave]

 

 

Well here is my 4th attempt at a bow and my first try at a r/d laminate bow.  The stack is all wood no fiberglass, 1/8" of hickory, 2- 1/8" strips of red oak and one 0.002“/in tapered strip if red oak on the belly.  Hind sight 20/20 I should have tapered it 0.004" the tips are a little stiff.... but since its all wood ill just sand some more off   .  Anyway, any help hints or tips would be great.  Im definitely a little worried with the tillering, its not like tillering a long bow!!!    ill try to post some picture of it on the tillering stick in the next day or two.

[LittleBen]

My advice on all wood laminate bows:

First, since wood takes set, unlike fiberglass, you need to start with at least an inch or so of reflex to end with tips in line with the back. It looks like you have a bit more deflex than refglex and I think you will end up with alot of string follow ... not that it won't shoot but you'd get better performance with a tad of reflex.

Second, I think hickory is a great backing, shouldn;t be anything wrong with oak for a core wood really ... There are probably better core woods, but I think the differences are almost purely academic and I doubt someone could tell if you blindfolded them and had them shoot it.

Red oak, is not particularly strong in compression. You didn't mention the length and width, but it looks around 64-66" long and maybe 1.5-1.75" wide. You also didn;t mention your draw length or the riser length. Loos like about 12" of riser length from tip of fade to tip of fade. So for a 66" bow, that would leave 54" of total working limb, and 27" working per limb. I think thats probably cutting it close. I think you're likely to end up with more set than you'd like, and possibly compression fractures depending on the draw weight and draw length.

For me, with a 25" draw and 40# weight, it'd probably be fine, but 50#+ and 28", I think that oak is going to be crying for help.

Give us some more specs and we can start talkign details.

In general though I might consider tillering the bow to say, 10-15lbs light of where I wanted to be and then add a parallel belly lam of osage or ipe .... or even hickory is stronger than oak in compression but osage or ipe is probably the way to go.

I don't mean to be harsh, just throwing all my ideas out there.

I do really liek the profile. I think the bow looks great ... just want to help you make it shoot great too. Good luck.

[DelawareDave]

Little Ben thanks! Your thoughts are exactly what I was looking for    I have never made a laminate bow and kind of made everything up on my own with what I had     the bow is 67" knock to knock the riser is 15" from tip to tip of faids and 1.75 wide limb, tapering to 3/4 at the knock.  I was hoping for 50ish at 28" but if it has to be less thats ok my dad is looking for a lighter weight bow    also I do have some very nice ipe at my shop and the means to resaw and grind lams so that is an option if u could give me some more details on it.  And thanks again!!!

[DelawareDave]

Also there is a little more reflex then it looks I took the picture at a bad angle  

[LittleBen]

Ipe is obviously much stiffer than red oak. I think what you've got right now is probably not going to make 50# @28" even if it stays together, but I think theres not quite enough thickness of oak to get there ... it'd probably be sclose though.

you could grind off the red oak belly lam (or if you used TBIII you can heat it and kinda pry it off ... but thats another story)

and I'd replace it with a 1/8" belly lam of Ipe.

Then I'd reduce the width of the bow to ~1.5". I'd keep the limb 1.5" wide to mid limb then taper to 1/2" or 5/8" nocks ... once you're tillered and the limbs are bending without any twist, you can narrow those tips alot ... down to 3/8" or 1/4".

The only problem I can forsee is that you dont have any taper built into it except the belly lam. You could put .004" taper on the ipe belly, but with a .125" butt thickness, you'd have only about .025" thickness at the tips, and thats not a good plan.

Personally I would probably tiller the bow out as it is, without removing anything, and see what the weight comes out to first, if it starts to chrysal etc. then I would say just starting bringing the weight down, keeping the tiller nice, until your thickness at the fades is .375" and then add the ipe belly lam, retiller etc.


In the future, I;d recommend putting at least half your total taper in the core because it avoids alot of this problem.