Primitive Archer
Main Discussion Area => Bows => Topic started by: superdav95 on June 18, 2022, 11:13:37 pm
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Inspired by bowEd I’m endeavouring to make my molle style bow but much shorter and add sinew and horn. My goal is to have 3 bows roughed out and heat treated the next week or two. All similar dimensions with slight variations. The target draw of these is around 45-50lbs. I’ve got 2 roughed out now one to go. The working limbs on these is short! Roughly 12”. The overall length of the bows is 58”. The levers or blades are also 12”. They will be narrowed significantly later one but for now they are about 1/2” thick and about 2” tall. The width on the limbs one the first one is about 1 3/4” wide tapering down to 1 1/2” wide just before the blades. The second one is same except limbs are wider. 2” wide for entire limb length. This one I have plans to leave it with just sinew backed and no belly lam of horn. The first will get the belly horn lam. These two were made using fairly green hickory harvested mid last month. The last one which I’ll rough out next week will be made to same specs as the first one but using a fully dry seasoned hickory stave from last year.
I’m testing out a few things here with these three bows.
1. Will there be any noticeable benefit to working the first two green and pre bending into a form with reflex (Approx 8”) Over the seasoned dry wood.
2. Will 12” of working limb be enough for my target 29-30” draw. I’m hoping with sinew I’ll be able to achieve this.
3. How thin will I be able to go on my blades/levers and still maintain stability. My guess is around 1/4” but we shall see.
4. Shoot ability. Will they be nice to shoot. Will they be efficient? Will the finger pinch be an issue.
This will be a build along of sorts over the next 6 months or so. Thanks for joining along!
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very cool...another one to look forward too and Ed will be able to help for sure. :OK
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Ya I’ll be picking his brain on these ones!
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with a horn belly no problem. A horn belly doesn't need to be more than 1 1/4" wide.
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All good questions you've made here.
No moss grows under your feet.That's for sure.
Never made them that short with that amount of draw without horn.
Look forward to the outcomes.
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Hmm. Ok then. The horn strips I have access to are only 1 1/2”-1 3/4” wide. I’ll have to tweak my limb widths a bit or maybe find a way to do 2 identical strips on each limb to get my width. Any thoughts on this is it possible?
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ok just guessing,, but 58 inch bow with 30 inch draw,,is gonna have some string angle issues,, right,,
it will probably shoot similar to any straight tip bow bow drawn to 30 inches,, a far as the bow holding up,,I have no idea,,
my guess is, that if you shoot it through a chrono graph as you tiller it out,, somewhere around 27 inches it gonna shoot hard and as you tiller it out longer, it may not shoot much harder,, or possibly fail,,
but like I said just guessing,,
enjoy,, and next time you will know,, like I said if you shoot it through a chrono as you tiller you will have a better idea what the best draw for that bow will be next time,,,
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As I said you don't need any more than 1 1/4" for any draw weight. Going wider is simply going to lower efficiency. As Brad says your problem will be string angle making it uncomfortable. Short hornbows have recurves in one form or another a) to stress the horn sufficently and b) perhaps more importantly string angle.
A stacky bow is not comfortable to shoot nor are they very accurate due to any variation in drawlength storing quite different amount of energy.
Anyway it will be cool to see what you come up with.
Another tip is to remove the excess wood in the handle and levers before doing any centerline layout. Any potential tension in the wood releases as you work things like that down. it would be a shame for the tips to move out of alignment.
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ok just guessing,, but 58 inch bow with 30 inch draw,,is gonna have some string angle issues,, right,,
it will probably shoot similar to any straight tip bow bow drawn to 30 inches,, a far as the bow holding up,,I have no idea,,
my guess is, that if you shoot it through a chrono graph as you tiller it out,, somewhere around 27 inches it gonna shoot hard and as you tiller it out longer, it may not shoot much harder,, or possibly fail,,
but like I said just guessing,,
enjoy,, and next time you will know,, like I said if you shoot it through a chrono as you tiller you will have a better idea what the best draw for that bow will be next time,,,
Actually that’s a good point. I’m gonna have to pay attention to my string top angle and aim for 60 degrees as many have suggested. I built a bow a month or so ago out of bamboo that also was 58”ntn and got it to 30” draw but found that it’s fastest speed readings were at 29”. My string angle on that bow was about 60degrees full draw at the tips. It’s definitely gonna be something to watch for. I like the idea of fine tune tillering as I speed test also. Think I’ll try that! Thanks
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Got the third one roughed out today and on the form to dry a week or so with the others. It was seasoned wood but letting it sit anyway. Bownarra, I did narrow up the handle on the one bow too. I may steam bend a straight recurve at the transition of the blades to assist with string angle a bit. It will be similar to my short bamboo bows siyahs angle. Now the blades are straight inline with the limb tip. I think that I will need to rethink the blades shape for now and focus on getting my angles steamed it and then perhaps do a laminated section of wood glued on after heat treatment and shaping are done to get my blades at that point. The reason I think I’ll have to do it this way is the grain run out or exposed grain at the transition of the blades and limbs. It will be much safer to steam bend in my angle there at one ring of wood. I can use that opportunity to straighten out and twist then to the blades tips and limbs. Each bow as it sits now has 9” of reflex on the forms. I hope to gain a few more during the sinew stage. I redid the form from the pics shown too. I’ll update tomorrow. I’m using ubolts at the ends to free up my clamps from heat damage from heat treat. Thanks for watching.
Cheers
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It looks like to me you will test the limits of hickory here.I figure there will be thickness reduction all along the working limb.
The worry about grain run out at the transition fades narrowing width is 1 reason why I like elm which is resistant to splitting and chrsalling too,but hickory is resistant to that too.Overlays there will stiffen it up quite a bit I'd say.
Do you like your hickory more so than your elm?
Hope you can keep the bow stable with long narrow recurves on such a bow.Not saying it is'nt possible though at all.
A few thoughts here.
Myself I've gone to a more streamlined look through that area [narrower overall but thicker] with transitional reflex overall to the tip with no thickness reduction along the working limb and with more overall length on the bow.
The area just outside the handle fades thickness will actually be the same thickness or less than the area farther up the working limb to the lever base,or close to the same thickness overall on the working section.Letting the width taper regulate the bend.
Much like a pyramid bow,with a long transitional thickness [4 to 5 inches] increase to the lever.With more longitudal violation with shorter working limbs.Keeping in mind the percentage of work a limb does or is able to handle along it's length.Farther towards the tip does less work so it needs less wood.Reason is I want to transfer more bending to the inner limb.Enough width is the key here to handle it.Hope I explained that clearly enough.
Like you I'm sure some failures are in store before it can finally be fine tuned to create time after time.You are progressing along faster than anyone I know.Including myself.Clean wood is a must here.It'll be fun to see what happens.
Another thing too is that even though the levers are purposed to be stiff they still do carry some of the work load to a certain degree.
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Thanks Ed. Some very good points there. I think I’ll end up doing long overlays starting at the transition area out to the tips. It’s either overlays or a v notch splice of some leftover heartwood from some hickory v’d in at my desired angle. This may prove to be a better option in the end. We shall see. This will help with my angle a bit instead of steam bending them as I worry about grain end there. Elm is nice for that for sure. Less worry with working in some heat bends. I still prefer hickory in the end as it’s easier to get clean straight pieces here and it’s very linear grain is very predictable. Heat treat works well on both too. I may have to try one of these if it makes it thru tiller. I think I’m gonna have to add an inch when I do the overlays too for length. Been thinking about this last night and I’ll need the extra inch for my target draw length and not be a beast to shoot. I like your gradual transitions on you bows. They looks very sleek and fast. My thinking on the thin blades may prove to be pointless but just trying to do something different I guess that also looks cool. My goal with this style is functional first so I may keep the reflex down to around 11-12” after sinew has dried. I may rethink the width on the wider limb bow in the end. Bownara suggested it may be a loss of efficiency. I may shape it the same as the others and try a boo belly lam instead of the horn as a test comparison. If I can get at least one thru tiller and glue ups without failure I’ll be happy and learn from it.
Ed, What type of glue do you use for the horn glue up on your highly reflexed bows??? Is it a mix of hide and fish glued or straight hide. Or do you use ea40 or some other epoxy.
Thanks again for all the tips and suggestions guys.
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Using denser materials the width will be reduced that's for sure.
I've used EA40 mostly applying horn.It holds up fine for me.Straight hide glue worked for me too.Controversy between fish bladder and hide glue or mixture of both resistance to moisture in hunting or pleasure shooting conditions has been a non factor for me in my demographic area.
I like to control my enviornment temperature while applying either to avoid gelling too quickly.Something anyone using hide glue soon learns too.I've used mostly just plain old hide glue.The lighter the color the better IMO no matter what kind used.Thin hide glue for sizing wood and a little thicker for sinewing and applying horn.
Performance from higher reflex using sinew is a lot more evident than without it.Like said and experienced by many once the wood cells crush it's all over for performance.There's a limit without using sinew.All things I'm sure you know already.
Hickory and elm both show to me to be resistant to chrysalling.Personally I like the very thin ringed hickory.Very little early wood in that stuff.Like you I see the elm take bends better too,but boiling hickory tips makes that easier too.
Sinew is some wonderful stuff.I hav'nt seen much difference whether the belly was heat treated beforehand or not either.Less need to reverse string much after heat treating reflex is done.
Getting a reflexed bow to brace at least to check for alignment and balance etc. without stressing the belly much before sinewing is a time saver.
It's always an adventure first stringing those bows after curing.
You should have fun with your future prospects.Hope it all works out for ya too.
Cool your showing the process also.It's good to see what natural materials will handle.
You have excellent roughing out bows talent there.
I see both of us striving to make lower poundage bows for ease of draw that will perform as well or better than higher poundaged bows normally made.
I've brought some rock elm staves inside to dry more quickly with the air conditioner and dehydrator running in the house.Along with some mulberry,osage,and ironwood.Got some very clean hickory staves also for some special projects down the line.
Chased a ring on this rock elm too and there us 0 evidence of early wood in this stuff.Had to start on 1 end of stave checking end grain to be sure I removed just 1 ring.Should be some good wood.Not as hard as this ironwood yet though,but cleaner wood overall.
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Interesting Ed. I’ve used ea40 for a couple horn glue ups and they seem to hold up. The can instructions seem to suggest 2 parts a and 1part B for best resistance to heat and more performance. Also seen guys heat box after glue up during clamping. I’ve never done this myself I just let it sit a couple days. I’ve used a mix of sturgeon and hide glue for horn and sinew too. So far so good. I had one failure on the sinew lifting off the core mid limb on me on a horn bow. I think it may have been a lack of thorough sizing perhaps. Upon inspection it appeared that the core under the lift seemed clean and dry. Grooves looked good but not enough glue maybe. The original molle I’ve got going now seems to be holding up good though. Did some test bending to brace and no weird noises or anything and seems pretty even bend. Horn had some discolouration up near the fades area but hopefully all good. I used all sturgeon glue on that bow. Including the sinew. We shall see. It looks more streamlined at the tip transitions compared to my short molles blade bows. One thing I’ve noticed in comparing sturgeon glue to hide glue that I did not expect. The water resistance or moisture resistance nature of sturgeon glue compared to hide. When handling different bows with different glue you become aware of that sticky aspect of hide glue much more then sturgeon glue on a humid day. The sturgeon glue didn’t feel sticky hardly at all in fact. While the hide glue did. Also the smell is quite strong on the hide glue compared to sturgeon glue. The hide glue I have is not made by me and was purchased from 3rivers I think it’s granular dried and needs to be rehydrated. Seems like good stuff but not sure how it would compare with home made hide glue. My plan with these short molles is to bake in most of the reflex as seen on the forms then gain an inch or two more with the sinew after applying horn. I’m on the fence about what glue I’m gonna use for the horn. If I do end up using ea40 for the horn I think I’ll make a heat box to cure it first then pull it out and do the sinew. Should be interesting anyway. I may do one with sturgeon glue and the others with ea40 for the horn to test the capabilities of the glues. Thanks again for all the great feed back.
Cheers
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Good points about the differences between hide and bladder or sturgeon glue.
Maybe the reason I see no difference in the handling of a bow is that I finish mine with a top quality spar varnish.
I have noticed a tacky feel to a handle finished with TB 3 though without any varnish on it.
The hide glue I use does not smell offensively while using it.Rather sweet really.When it dries it is almost like transparent glass.
My concern is in it's ability to hold up during use in demographic conditions.Of which I see no difference in my area and only making bows 55#'s or less in draw weight.
Could be with bows of higher draw weight of 100#'s or more that bladder or sturgeon glue is better though as in Adams' comments about it.Of which I cannot comment on.
I've heat treated EA40 before many times,but mostly let it cure a good 24 hours nowadays.I'm sure there's a benefit according to the manufacturers' instructions,but none I've noticed either through useage.As long as the EA40 is of good quality and the prepping done right it'll do it's job.
I do put my tip overlays under a heat lamp regularly yet.Usually 150 to 160 F. for 5 to 6 hours.Never had one come off.
One thing.It's good to reverse string these sinewed bows.Compressing the sinew as you go progressively.At or during the gelling stage into a finished crowned application appearance.It likes that and will pay you back in helping to hold reflex also.
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Great tips Ed. I did up my lightning bolt tip overlays yesterday on my composite molle bow yesterday. Here’s a sneak peek. Thanks again.
Cheers
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Update on my progress on these bows. I decided to steam bend 2 of the bows and will leave one to do the v splice method. There was a little lifting of end grain where the transitions occurs at the start of the blade tips but can fill in with some glue later if needed. One bow I cut down the hiwght of the blade to keep to one ring thickness and will let dry overnight in the forms. Here’s a few pics.
Thanks for following along.
Dave.
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Hide glue for very dry climates, fish bladder for more humid areas. It does make a difference 100%.
EA40 is stronger when mixed 2:1 and cured at 40 degrees. Its heat resistance definitely goes up too. It will of course hold horn to a core...but I see it as a bit of a cop out when making a hornbow - I like them to be traditional - to each his own. Importantly the bond between horn and core is one of the last to be affected by rain/humidity. the sinew is the weak link with reference to humidity. Often the belly of hornbows wasn't even covered or finished - no need. The painting and leather covering are simply to protect the back (and maybe the edges a little).
I still think the issues with these bows will be stack.
You mention adding a little more reflex. If you don't pull the tips together when adding layers after gelling, before any drying takes place you risk the sinew delaming. Personally if I made this sort of bow I would want the tips touching. The horn and sinew can take it easily. String tension at brace is one of the main reasons hornbows shine. You can't have too much reflex!
Good luck.
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Hide glue for very dry climates, fish bladder for more humid areas. It does make a difference 100%.
EA40 is stronger when mixed 2:1 and cured at 40 degrees. Its heat resistance definitely goes up too. It will of course hold horn to a core...but I see it as a bit of a cop out when making a hornbow - I like them to be traditional - to each his own. Importantly the bond between horn and core is one of the last to be affected by rain/humidity. the sinew is the weak link with reference to humidity. Often the belly of hornbows wasn't even covered or finished - no need. The painting and leather covering are simply to protect the back (and maybe the edges a little).
I still think the issues with these bows will be stack.
You mention adding a little more reflex. If you don't pull the tips together when adding layers after gelling, before any drying takes place you risk the sinew delaming. Personally if I made this sort of bow I would want the tips touching. The horn and sinew can take it easily. String tension at brace is one of the main reasons hornbows shine. You can't have too much reflex!
Good luck.
Thanks for the info bownarra! I’ll have to dig out some good pieces of horn for these ones. I’ve noticed the humidity factor with the difference in hide or fish glue. I do worry too about stack. I may have to settle for shorter draw in the end. Thanks again for the input