New bow from a newbie

[Slackbunny]

I don't think this bow is as far gone as many of you believe. It does look really bad at first glance, and I had the same reaction as most of you at first. Then as I got thinking about just exactly what was wrong with it, something came to mind. Its really close, geometrically speaking, to a 3 piece takedown.

If you put a couple bolts through the back of the limbs where they affix to the handle and put some nuts and washers on them like a 3-piece takedown, then I think that would make this bow safe. That is if the tiller is good, especially right out of handle.

Even with a good solid glue line (which you do not have in this particular case), I would not trust it to hold against the leverage of the limbs especially at that draw weight. Yes a perfect glue line is supposed to be much stronger than the wood itself, but only in pure axial loading conditions. When you start applying stresses that do not fit these conditions (and bow limbs do not), then the strength of the glue line becomes suspect.

This particular bow is not remotely safe in its current state. That glue up is not up to the task based on the looks of it. And even a good glue up would be very very suspect in my opinion given the leverage and loading conditions present. Personally I would put some bolts through it, not just pins, but bolts with washers to spread out the holding power. You want holding power perpendicular to the limbs to keep them from lifting off the riser.

[iangriffin]

Hi slackbunny
Thanks for your input.

[Andrea S]

Ian,

You were looking for logical explanation as to the inefficiency of your design. Here's a simple illustration as to why the earlier "pry bar" analogy was apt. The stiff and abrupt handle transition, because it does not fade into a working, bending piece of the bow, acts as a fulcrum for the overall movement of the limb.

Let's look at this from the view of what you were trying to achieve when you came up with this design: distinctly reflexed limbs, correct? A safer, more efficient and effective way to achieve this is to glue up continuous laminations in the reflex shape. If someone could provide a link to a good build-along, that would be appreciated.

[PatM]

I don't think this bow is as far gone as many of you believe. It does look really bad at first glance, and I had the same reaction as most of you at first. Then as I got thinking about just exactly what was wrong with it, something came to mind. Its really close, geometrically speaking, to a 3 piece takedown.

If you put a couple bolts through the back of the limbs where they affix to the handle and put some nuts and washers on them like a 3-piece takedown, then I think that would make this bow safe. That is if the tiller is good, especially right out of handle.

Even with a good solid glue line (which you do not have in this particular case), I would not trust it to hold against the leverage of the limbs especially at that draw weight. Yes a perfect glue line is supposed to be much stronger than the wood itself, but only in pure axial loading conditions. When you start applying stresses that do not fit these conditions (and bow limbs do not), then the strength of the glue line becomes suspect.

This particular bow is not remotely safe in its current state. That glue up is not up to the task based on the looks of it. And even a good glue up would be very very suspect in my opinion given the leverage and loading conditions present. Personally I would put some bolts through it, not just pins, but bolts with washers to spread out the holding power. You want holding power perpendicular to the limbs to keep them from lifting off the riser.

     Fiddler posted this idea already a few pages back.

[PatM]

With all the talk about Grozer and Kassai style bows why not just make one of those in wood?
 

[Slackbunny]

I don't think this bow is as far gone as many of you believe. It does look really bad at first glance, and I had the same reaction as most of you at first. Then as I got thinking about just exactly what was wrong with it, something came to mind. Its really close, geometrically speaking, to a 3 piece takedown.

If you put a couple bolts through the back of the limbs where they affix to the handle and put some nuts and washers on them like a 3-piece takedown, then I think that would make this bow safe. That is if the tiller is good, especially right out of handle.

Even with a good solid glue line (which you do not have in this particular case), I would not trust it to hold against the leverage of the limbs especially at that draw weight. Yes a perfect glue line is supposed to be much stronger than the wood itself, but only in pure axial loading conditions. When you start applying stresses that do not fit these conditions (and bow limbs do not), then the strength of the glue line becomes suspect.

This particular bow is not remotely safe in its current state. That glue up is not up to the task based on the looks of it. And even a good glue up would be very very suspect in my opinion given the leverage and loading conditions present. Personally I would put some bolts through it, not just pins, but bolts with washers to spread out the holding power. You want holding power perpendicular to the limbs to keep them from lifting off the riser.

     Fiddler posted this idea already a few pages back.

Oops,I guess I must have missed that.

[SLIMBOB]

Still whipping the horses eyes... Gun doc is completely right. The op knows what the consensus is. He just needs to get a bunch of em done, and then look back at that body of work. Not knowing what you don't know. We were all there once.

[iangriffin]

Hi all
My bow is on the backburner for the now. This means a long time. I would like to ask a question. Is it at all possible to join two limbs together for an 80lbs bow? If so how? Forget about my previous design.
Regards Ian

[Blaflair2]

What do u need to join two limbs? Why can't ya just glue the whole shebang with full length limbs. If u wanna join two limbs use a takedown sleeve or a 3 piece takedown design. U can glue in reflex a lot easier I think I'll be happier with the outcome. Whatever ya decide. Post pics. We're here to help

[PatM]

Explain your reason for separate limbs.

[bubby]

Yes you can use a fishtail splice in the center of the bow and do a thin veneer over the splice and riser on belly side, there are lots of splices w z all will work, if you want to splice to get reflex i suggest you go thru Mark st Louis posts he builds some highly reflexed flight bows and hi performance type bows

[Onebowonder]

When I was trying to do this is was because of the difficulty in finding lengths of quartersawn lumber that did not have excessive run out.  I could readily enough find such at 3 - 4 feet long - but much less readily at lengths of 5 - 7 feet.  I've no idea if this is Ian's issue, but it was what started me down the same road.

OneBow

[iangriffin]

Hi Guys
Thanks for the info. My reason is that I only have 5 foot lengths of 2 x 4. I had too high expectations in the beginning plus I can collect them in my car. I am nearly skint. Some posts told me that I'm expecting too much from the limbs on a short bow. I plan on dropping the ash backing. I read that maple makes a good backing. I have 2 lengths each of maple and oak. If I have to build a short bow, I'm thinking 4-5 mm of maple for the backing. The core will be 3mm maple ,1.5mm x 2 of oak, 3mm maple and 4mm oak for the belly. The assembly order will be maple+oak times 2. Tapering by scaper, 1 in 4 for the oak sides and 1 in 5 for the maple sides. If I'm happy with the tapering, Glue on back and belly. This is for a short bow with a shortish handle to give as much as possible working limb. If I can splice 2 of these limb. I will make a much longer bow with a bigger handle. I am very aware of making the fades smoothly blend in. Answer any way you feel correct. I promise no more tantrums.

[Blaflair2]

5' is 60", u can swing it. If u made it more of a bendy handle I think itd work for ya, also where u tried gluing in reflex on the other bow, straight outta the handle, reflex is better at the tips. I'd make a form with some 2x4s. Put a 3/4"  piece of wood in center and say 2" blocks under each tip, when u glue it wrap in old inner tubes and clamp in form in disired shape.

[PatM]

Not sure why you wouldn't just extend the tips as I showed since you seem to like that style.