Primitive Archer
Main Discussion Area => Bows => Topic started by: superdav95 on February 12, 2026, 11:01:04 pm
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Ive taken a brief break from my arrows to build another bow ive had rattleing in my brain for a while. Ive done similar ones like this but this deflex reflex design in a boo on boo is a first for me. Most of the time spent was figuring out my thickness tapers and selecting the right 2 sections of boo slats. I plan to side tiller only this bow to retain all of its belly and back intact. I have a three part video series on youtube that I started and will continue to post updates. the first link here is the 3rd video showing where im at now with it. More work to do on it yet. Im hoping to have something close to 70lbs. if i miss this mark ill shoort for 50lbs. If i feel like its performing well ill bring it to flats.
https://youtube.com/shorts/rut6d_2v0Qs?si=njvBsEtxnJg7-KNK
Link for pics
https://share.icloud.com/photos/024rIt--4qhbW2NPBgd50kpqw
(https://i.imgur.com/2i3XrD0.jpg)
(https://i.imgur.com/3BAu2vX.jpg)
(https://i.imgur.com/SMFC6Ci.jpg)
(https://i.imgur.com/pGEuuTV.jpg)
(https://i.imgur.com/a5a0kb6.jpg)
(https://i.imgur.com/XSHRf1J.jpg)
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I saw your utoob video of this coming bow. Very promising.
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thanks hamish! glue lines look good so far so good. I did a deeper cook on the belly lam prior to glue up. I figured on the belly that would be best we shall see. the back i only did a mild cook. The cook on the belly maintained color change deeper then the back. The nodes are spaced accordingly belly and back.
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Good luck! I built something similar and it got so narrow I was loosing side stability and it wanted to flip on me. I had to reduce the reflex by cutting the tips, which caused the weight to go back up. Im expecting to see you fight a similar fight.
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Good luck! I built something similar and it got so narrow I was loosing side stability and it wanted to flip on me. I had to reduce the reflex by cutting the tips, which caused the weight to go back up. Im expecting to see you fight a similar fight.
Thanks I’ll need it. I hear ya. These are a challenge. I have been able to get lucky with these so far. I’ve had my share failures too prior to that however. The neutral plane is also important factor with these type build. Also careful measures. I carefully measured my tapers and got pretty close. Fingers crossed and time will tell if I got them right.
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Love it. Thanks for doing this because I want to do the same but in a lighter 45# draw weight. The side profile looks good. If it works for you, I plan to do one with just a little more deflex in the middle. :OK
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Im following along as well. Silly idea... instead of removing wood from the belly or sides could you tiller by drilling holes or a vertical hollow groove along the center of the limb? Starting small and varying size and placement to achieve perfect tiller? If anyone can figure this out its you.
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Im following along as well. Silly idea... instead of removing wood from the belly or sides could you tiller by drilling holes or a vertical hollow groove along the center of the limb? Starting small and varying size and placement to achieve perfect tiller? If anyone can figure this out its you.
not sure on that Doug. i could see it splitting under stress though.
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Love it. Thanks for doing this because I want to do the same but in a lighter 45# draw weight. The side profile looks good. If it works for you, I plan to do one with just a little more deflex in the middle. :OK
Thanks Bob. Its doable but be accurate when measuring your slats for thickness and get them to about .225" mid limb for about 8-10" and then increase taper thickness towards tip and handle. it may seem thin but bamboo is a different animal! The tip thickness on each slat would be .260-.280". if doing one similar to mine here the handle section leave as thick as you can and then taper from that to mid limb at .225". if doing a power lam in handle section instead then i would actually thin it down more for the 10-12" the is centered in the handle. This will allow it to conform well and give good glue lines around your power lam.
This is all of course based on previous builds notes anyways. results may vary wildly depending on your bamboo quality and crown and heat treatment if used or length of your bow. Ive always believed in sharing my so called secrets and feel that for the most part its all been done already anyway by somebody out there. I believe that is what this site is for. the bow im making here had thicker slats of about .250" in the mid sections for a combined overall thickness of just over .500" when glued up. similar tapers as described above. i figured it would get me the wiggle room needed to potetially get a a 70lb bow. Also. when side tillering be sure to round your edges and almost like a shallow faceted style tiller to help control weight reduction and prevent lifts. The last bow i did in the weight range you described was a great shooter and used these measures. it was a much shorter bow then my build here though. it also incorperated a power lam in handle and the tips. Ill keep posting updates here too but my utube channel is where the video updates on this will be. reach out with any questions too. cheers
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so Ive got this bending not too bad. its heavy which i want! shooting for 70lbs. to my eye the inner limb is bending little more on the right (bottom limb) side then the other. its at around brace height here. reflex is hold around the 4" mark so far. I will continue to monitor it. Im hoping to retain around 3" after its done. this bow will have semi stiff tips or recurves. its a tall order for these kind of builds as the tillering is on the side only by choice. heres a couple pics of the bend so far. what you guys think.
(https://i.imgur.com/iIjN9sP.jpg)
(https://i.imgur.com/RafrcG4.jpg)
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Have you seen any of Meadowlark Adventure Gear's Youtube videos? He does lots of boo back and belly bows. He will even do some tillering on the belly, usually only to tweak tiller, rather than large adjustments. Too much work you risk going through the power fibres and exposing the softer fibres to compression.
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Hey Hamish. Ya I have checked his vids out. I do like his methodical approach. He’s made some really nice bows. He normally uses a core wood more often if I recall and with a power lam riser on his builds. I’ve done these type builds too with some success and failures. Always some failures. The biggest issue I had and I think him also was splitting of the thinner strips of boo at the riser ramp. What ive done to combat this is heat in this ramp on the slat before taken down to final dimensions. This allowed me to get more safety in that area. I also heat treat mine more heavily than I think he does. We shall see how mine goes as I tiller it out more. You are right about the belly power fibers. I’ve made that mistake on a previous attempt. It actually stress fractured on me as I was trying to get it to brace. Hence the failure on that build. I also used to torch the belly rind side and I don’t do this anymore since a failure there too. Cracks developed. Instead now what I do for the belly lam is do a much deeper cook on the flesh side leaving the rind side alone. I will go with the cook long enough however till I see a shiny glaze appear on the power fiber side. This indicates to me that it’s a fully cooked from the inner out to the outer rind where the lignins and pectins ooze out and harden. When it cools it’s actually like a laqure hard finish on there. I’ve had better luck doing it this way.
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Good info, "I will go with the cook long enough however till I see a shiny glaze appear on the power fiber side. This indicates to me that it’s a fully cooked from the inner out to the outer rind where the lignins and pectins ooze out and harden. When it cools it’s actually like a laqure hard finish on there. I’ve had better luck doing it this way."
Yes Joddy, from Meadowlark focuses mainly with a wooden core, power lam's as you mention. He has mentioned the same problems, you clearly have watched his videos, and taken in good lessons.
It's good to see people experimenting. High risk, though the reward is high when you are successful.
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Worked a bit more on this bow today and got it braced. The outers were a little stiff and still may in fact be a little bit stiff yet. I pulled it to around 22” about a dozen times or so to work in some of the changes I had made to balance things. Seemed to take to them well and looks better now. Slightly positive tiller on top longer limb which I’m fine with and may work to maintain that moving forward. It feels about 45-50 lbs at 22” now by feel but may be a little shy of my 70lbs target. We shall see. I left it strung for about 45min after pulling it some to see where it settled. prior to the changes and getting it braced i had around 3.5" reflex. I now have around 3". we shall see what i can retain when done. I don’t have a way to take video that would be worth anything of me drawing it at the moment. I’ll see if my camera lady can help take some video. Here’s a clip link from YouTube showing how braced.
https://youtube.com/shorts/7HgF1IWLxxQ?si=VBuy_zlHTp_FG1Uw
Link to pics
https://share.icloud.com/photos/0bc8fUTd1PD_rYq9_TNk9wKyQ
(https://i.imgur.com/5nMTfR8.jpg)
(https://i.imgur.com/Oqcb7SX.jpg)
(https://i.imgur.com/8bQl4Zf.jpg)
(https://i.imgur.com/lsuRZcH.jpg)
(https://i.imgur.com/B9TDOqk.jpg)
(https://i.imgur.com/YpRc56y.jpg)
(https://i.imgur.com/Uac3qvY.jpg)
(https://i.imgur.com/AbQNnKe.jpg)
(https://i.imgur.com/igzM5bK.jpg)
(https://i.imgur.com/eXjkpNZ.jpg)
(https://i.imgur.com/9mhkSBL.jpg)
(https://i.imgur.com/uWukYfl.jpg)
(https://i.imgur.com/otor3nW.jpg)
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Looking really good so far.
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I narrowed up my tips to 3/8". The forcedraw curve shown is out to 25" draw at 58.80lbs. brace height from the back of the bow to the string is 6.5". I measured the first 1/2" to 7" then every inch after that. The question is do I keep going? or do i call it where it is as i will not likely reach my target of 70lbs at 28". It might be close. if i go to 28" i figure around 65-67lbs??? let me know what you think. the set back is holding pretty well so far. only lost about a 1/4" right after unstringing. I suspect it will creep back most of the 1/4" through the day. what think you fellers????
Link for pics
https://share.icloud.com/photos/0db0N--bglxf8wSy6NQY__AIw
(https://i.imgur.com/Wkw3b3V.jpg)
(https://i.imgur.com/8P3AgFu.jpg)
(https://i.imgur.com/mqRWumP.jpg)
(https://i.imgur.com/wMf3V1H.jpg)
(https://i.imgur.com/ArUSPYH.jpg)
(https://i.imgur.com/boFPH3A.jpg)
(https://i.imgur.com/90ambOJ.jpg)
(https://i.imgur.com/YOB7gC5.jpg)
(https://i.imgur.com/p5HndMU.jpg)
(https://i.imgur.com/AbQNnKe.jpg)
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This is looking super snappy, I really like the profile it's keeping! Are you going to wait until the salt flats to do any full draw or shooting with it? It's looking awesome so far.
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This is looking super snappy, I really like the profile it's keeping! Are you going to wait until the salt flats to do any full draw or shooting with it? It's looking awesome so far.
Thanks Robert! It feels snappy. I’m gonna take this one as well as a few others out to a long field to distance check in the spring. I’m Just putting the finishing touches on my flight arrows so will have something to shoot. I’m also trying to decide whether or not I should continue with this bow or not as it will come short of my 70lb target. More like 65-67ish. Looking for input from other bow nerds to take a look at the draw curve and give me some direction on this one. Not really sure what to do with it. Option 1. Reduce it down some to 50lbs at 26” like my self bow or option 2. Try to continue out to 29” draw and hope I’m close enough to 70lbs. Option 3. Start over. For all those reading and following should I try to take it to 29” and hope I don’t be way under 70lbs thus having to shoot a longer arrow also but it may be worth doing still??? Let me know what you think.
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I've recently read something interesting, I don't know if it's relevant here and it sounds relatively risky anyhow:
Some flight archers shooting to break records will intentionally overdraw a lighter bow, say a 45# @ 28" drawn to 50# @ 30" (hypothetical numbers). Rather than shoot a bow that has been tillered to 50# @ 30# off the bat. I wish i could remember where i read this. It seems like a way to under build a bow on target for very dangerously low mass intentionally and squeeze the very most out of a flight bow. Maybe it also ensures compressive stress is kept to an absolute minimum prior to shooting.
Does this ring true or make sense?
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Robert what you describe is essentially what I may end up doing as option 2 for the 70lb class simple composite. I’ll have to be prepared to build a long enough arrow to get as close to 70lbs. This will mean a longer heavier arrow though but still may do well enough. Thanks for the input.
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I've recently read something interesting, I don't know if it's relevant here and it sounds relatively risky anyhow:
Some flight archers shooting to break records will intentionally overdraw a lighter bow, say a 45# @ 28" drawn to 50# @ 30" (hypothetical numbers). Rather than shoot a bow that has been tillered to 50# @ 30# off the bat. I wish i could remember where i read this. It seems like a way to under build a bow on target for very dangerously low mass intentionally and squeeze the very most out of a flight bow. Maybe it also ensures compressive stress is kept to an absolute minimum prior to shooting.
Does this ring true or make sense?
Robert, thats 99% correct, at least to what I try to do when it all comes together. I will design a bow to pull 50@26, and tiller it out to be 44@24 and stop, never actually hitting 50 pounds ever on the scale. When it comes time to shoot the bow in flight, the ideal situation is the first time it ever hits 50 is at the weigh in, so its fresh. I make my arrow rest adjustable so that if its a little over and hits 50@25.5, I can move the rest to that position allowing my draw to be spot on.
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Dave if you have a shelf how are you going to keep the bow together at the handle attachment? I must not understand what I’m seeing in the photos.
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Ya Arvin the pics don’t show it clearly. It’s glued to the wood handle and then wrapped with strong cord. Artificial sinew actually. I’ll switch this up to flax cord later. Similar to my other boo bow builds like the one you have it’s also got the relief ramp at the end of the handle on both ends. I’ve got a 26” flight arrow to test out this bow to see how it does at 28” draw. I’ll try to post more pics.
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here are some better pics of the handle Arvin.
on related note, i may have a solution to reach my 70lb target. the bow right now sits at 69"ntn. I could move my overlays inward 1/2-3/4" or so on each side and it wouldnt mess with my tiller too much and add just enough draw weight. I may try this in next couple days and see how it goes. With some work the bow did balance out fairly nicley so this may be a good option for me without having to start over.
(https://i.imgur.com/TYTdptE.jpg)
(https://i.imgur.com/UvRqhRR.jpg)
(https://i.imgur.com/1tJGayw.jpg)
(https://i.imgur.com/1qvlNBn.jpg)
(https://i.imgur.com/GbLaqWc.jpg)
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Ok so I’ve popped off the horn overlays and moved them in an inch on both ends and reshaped them as before. We shall see where we are as far as any increase tomorrow. It’s now 67”ntn. I did loose a little reflex height as a result. It’s now just over 2”. I’ll get some projected draw numbers and update.
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Be careful doing that. Moving the tips in changes the tiller shape, stressing the inner limb more.
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With such low set, I might have prioritized the shorter weight and draw length. Hopefully pushing it won’t stress it too much more. Looks really impressive.
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Dave somewhere you had mentioned shooting a fresh bow that had never been taken to full draw. I know of some real-world cases, and it is dramatic! I made an English longbow for Josef. He broke a world record with it at 450 yards. The bow had been tillered to 28", and on his first shot in practice, he drew it further than 28 and shot 530 yards. Another bow I had, I was working on a bow between rounds at the flight shoots. The bow I was working on was just a regular straight bow with about 1" reflex natural. Just for fun I decided to shoot it without ever having drawn it back before and I hit 387 yards. with a 50# bow. If you test this on a crono you will see how dramatic the results are. Build a simple shooting machine and use it with a scale in line that can hold the pondage reading. Tiller your bow out to about 24" tops and when you project it will hit 50# put it on the shooting machine. It is amazing how much we loose even on our best bows.
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Be careful doing that. Moving the tips in changes the tiller shape, stressing the inner limb more.
Ya I thought on it a while and came to the decision to try it. I haven’t put a string on it yet to see how it’s changed it up. My thinking was it was pretty long as it was at 69” ntn. The sweeping tips seemed to have plenty of length yet when looking the profile. Fingers crossed I guess. Worst case I’ll just build another. This one only took me a day to get glued up.
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With such low set, I might have prioritized the shorter weight and draw length. Hopefully pushing it won’t stress it too much more. Looks really impressive.
Thanks Ryan. I was originally thinking of just leaving it as it was. Making the change to shorten it may be a mistake and put more stress past the tipping point. I’ll see when I get it strung up to see for sure. Nothing ventured nothing gained I suppose.
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Dave somewhere you had mentioned shooting a fresh bow that had never been taken to full draw. I know of some real-world cases, and it is dramatic! I made an English longbow for Josef. He broke a world record with it at 450 yards. The bow had been tillered to 28", and on his first shot in practice, he drew it further than 28 and shot 530 yards. Another bow I had, I was working on a bow between rounds at the flight shoots. The bow I was working on was just a regular straight bow with about 1" reflex natural. Just for fun I decided to shoot it without ever having drawn it back before and I hit 387 yards. with a 50# bow. If you test this on a crono you will see how dramatic the results are. Build a simple shooting machine and use it with a scale in line that can hold the pondage reading. Tiller your bow out to about 24" tops and when you project it will hit 50# put it on the shooting machine. It is amazing how much we loose even on our best bows.
Yes! Badger. I hear you. Those are impressive numbers. My plan for this bow is to only take it to 24” and forecast as best I can to hit 70lbs. Whether that’s at 26” or 27” or more I believe the limbs can handle it. The limbs have shown to take little set thus far and so I may just bring it to the flats and see. I’ll be sure to have an assortment of arrow lengths in case on the day. I get your point and it is well taken. I think I will have a pretty good idea of where I will need to draw it to on the day by looking at the previous draw curve numbers and the new numbers. Thanks again everyone for your input.
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well that didnt work as I hoped! Heres are the numbers. see the pics below on the comparisons. the first set of numbers are before removing an inch off the tips and braced at 6.5". The right column of numbers are after the removal and braced slightly higher in hopes to eek out a pound or two more. didnt work really. its actually less early draw weight then before which puzzles me a bit. it catches back up at around 18" and then gains a couple pounds or slightly more each inch after this. could this still be a decent bow? maybe but i think ill just make a new one before the flats. here are some pics. It still looks good and i did take a little more set. immediatley after string and doing the draw numbers curve i retained a reflex of 1.75". prior to this it was around 2" so lost about a 1/4" right after unstrung. it crept back to 2" after about 5-10 mins. Thats a good sign. This is where this bow is at now I have to accept this and not the 5-7pounds increase i was hoping for. oh well thats the way it goes sometimes. I deceided to take it out to he garage and shoot it a little. Its actually a very nice and smooth shooter. only drawing to maybe 24-25". No noticable handshock and felt silky smooth. If not destined for the flats at least a half decent shooter. I may put some more permanent wraps on it and stain it up and see if it performs even better at my draw length of 29". I was worried about the tips having too much weight but seems good. Anyway on to the next one. I do think there is some potential for this type build in this simple composite class. Ill learn from this one and apply it to the next. More to come! thanks for following along.
(https://i.imgur.com/IYVlHNw.jpg)
(https://i.imgur.com/FJWb1YG.jpg)
(https://i.imgur.com/ONkLNlW.jpg)
(https://i.imgur.com/szbcJpU.jpg)
(https://i.imgur.com/0zexpYm.jpg)
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A higher brace will reduce early draw because the higher the brace, the less leverage the limbs have over the string. You should keep the brace as low as you can, while making it not hit your wrist and maintain good arrow flight. The more the limbs bend, the lower your string tension gets.
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A higher brace will reduce early draw because the higher the brace, the less leverage the limbs have over the string. You should keep the brace as low as you can, while making it not hit your wrist and maintain good arrow flight. The more the limbs bend, the lower your string tension gets.
Ok. That makes sense. Thanks Kevin!