Primitive Archer
Main Discussion Area => Bows => Topic started by: DC on July 02, 2020, 12:59:29 pm
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This is my latest attempt at 200fps. It's a Boo backed Yew 65"NTN following the curves. 1.25" wide at the fades tapering evenly to .75" at the base of the recurves. Tips are .4" wide. Weighs 492grams(17 1/2 oz). Draws 39#@28". Shoots 198fps@10gpp. Close but no cigar :D When I took it off the caul it had 5 3/4" of reflex. By the time I'd finished tillering it was down to 3 1/4". It was shooting around 195fps. I decided to try a 250 grain arrow. It shot 221fps but split the shoulders off the pin nocks. Don't use 6 strand D97 strings on pin nocks :D. You can see the splits in one of the pics. The string slide about 6" under the boo splits. I thought it was done for but I CA'ed the splits down. I had to pike it an inch because the tip was too damaged. So now it has 2 1/4" reflex. It gained 2# DW so I tidied up the tiller a touch and it ended at 39# but it shot 198 so I was pleased. I'm satisfied with the FD pic but the braced one shows that the bottom limb is too stiff. I may fix that, I'm undecided. I haven't shot it much so that will be the deciding point.
PS I just traced it out and flipped it and the lower limb has 3/8" more reflex so maybe the tiller is OK
PPS bad news. My scale has three options pounds, kilograms and jin. A Jin is a Chinese weight that equals 1.1023 pounds. My scale somehow got on "Jin" which is close enough that I didn't notice. So once I put it on "pounds" the bow weighs 42#, not 39#. This means my arrow was too light. True speed is 191fps. I'm bummed. I'm not sure when the scale got changed. I'm hoping it was recently. I thought this was too good to be true.
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That's definitely a recurve and a very nice one at that. Well done. :OK
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Wow DC, you came close to the bar.
Fine build btw. Well done.
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allllllllllllll...... most still v cool @ 198 8)
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Shoot it with a tail wind...
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How do you do your recurves??? Are you bending the yew and the bamboo separately then gluing up on the caul? I've not come up with a great solution yet. Thank you sir and strong work!!!
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Yes, I bend them separately. I steam the Yew and bend the Boo with a heat gun. Just heat the outside of the Boo and push it into a concave caul. It takes about two minutes to heat and bend, and about ten minutes to cool. I'll post a pic of the caul tomorrow.
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Very nice DC! How do you like the belly lam over handle design? I have always pondered trying it but haven’t attempted it yet.
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That is a great bow! Very impressive results. Do you happen to have a photo of your caul? Thanks!
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Very nice and fast DC. Have you built a fifty pounder like that? And would you get those # s with 50#Bow and a 450 gr arrow. Next why are you not at wendover? Arvin
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Nice, great speed for that poundage :o
Del
... and you've learned why people use tip overlays and not pin nocks >:D ;D ::) ;)
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How do you like the belly lam over handle design?
Good question. I didn't notice that on first look at the pics as I was too busy admiring the super clean detail work. Running the lam up the fades is the ultimate solution to handles popping off.
DC, did you steam and pre-bend the belly lams to fit up the fades?
Nice, great speed for that poundage :o
Why would the poundage matter much when the arrows are normalized to 10gpp?
Mark
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Very nice DC! How do you like the belly lam over handle design? I have always pondered trying it but haven’t attempted it yet.
I kinda like the look. I can get an extra 2.5" in length so I can use shorter billets. There is a bit of fiddling to get a decent glue line. These aren't as good as they look in the pictures. Sometimes a blurry camera is a blessing. I steam the belly to the curve I want and then trace that shape on to the riser. Then cut that out with the band saw.
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That is a great bow! Very impressive results. Do you happen to have a photo of your caul? Thanks!
I do one limb at a time because I overlap the boo at the handle. I do the recurves separately. I posted some pics of it in use a while back
The second pic is for bending the Boo
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Very nice and fast DC. Have you built a fifty pounder like that? And would you get those # s with 50#Bow and a 450 gr arrow. Next why are you not at wendover? Arvin
I can't pull more than 40# so I've never tried. I've wondered if it's easier to get bigger numbers with a heavier bow when you're doing 10gpp. The first bow I got in the mid 190's came in underweight at 35#. It made me wonder if lighter draw weight made it easier to go fast. But wondering is all I know about it.
I would love to go to Wendover but only if I had a transporter. I hate travelling. I also don't have a passport and that just adds to the hassles.
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Nice, great speed for that poundage :o
Del
... and you've learned why people use tip overlays and not pin nocks >:D ;D ::) ;)
Yeah, that kind of surprised me. I've used pin nocks on these bows because I thought they were lighter. They are a PITA as far as keeping track of your strings. Now that I've tried small overlays I'll probably continue with that. I'm thinking that being able to rasp off the shoulders will make up for the weight of the overlays.
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Running the lam up the fades is the ultimate solution to handles popping off.
DC, did you steam and pre-bend the belly lams to fit up the fades?
It probably is the answer to belly popping and it allows you to use those short knotty pieces of Yew you can't throw out :D but it just seems to be one step further from primitive.
Fitting the pieces together is the drawback. It's not that easy. Maybe now that I've posted how I do it(further up) maybe someone will have a clever way to make it easy.
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Thanks for all the nice comments guys. I'm close, maybe the next two or three bows will do it. Getting into the mid 180's was fairly straightforward but the last 10-15 fps have been hard. I've struggled to keep from going underweight and not made it on most of the last four or five. For some reason I've found RD's to be difficult to tiller. Wider limbs for less set just adds to that problem. Thin limbs are tricky. This one was a compromise between DW and better tiller. I've had to rebelly a few because of unfixable hinges. I'm now running out of Boo and Yew. Maybe 3 or 4 more bows. Have to make the decision whether to order more or just pack it in.
Thanks
Don
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It probably is the answer to belly popping and it allows you to use those short knotty pieces of Yew you can't throw out :D but it just seems to be one step further from primitive.
It solves the handle issues because the compressive stresses run up the belly surface around the outside of the handle instead of running along the glue line under the handle. That you can use shorter lams is also a significant bonus. If you are concerned with the level of primitive in your bows this certainly does move farther away from that ideal.
Fitting the pieces together is the drawback. It's not that easy. Maybe now that I've posted how I do it(further up) maybe someone will have a clever way to make it easy.
Did you do this one by gluing the belly lams to the handle and then belt sanding the back side of that assembly flat to fit the back lam? Considering how the fibreglass laminate bow makers prep and do their assemblies I don't think there is an easy way to do multi-piece bows, especially if you are trying for very high performance.
Mark
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Did you do this one by gluing the belly lams to the handle and then belt sanding the back side of that assembly flat to fit the back lam?
Mark
Yes
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I know what ya mean the 180s was pretty achievable. I’m still trying to get into the 190s. Keep them coming I am sure you will hit the 200 mark. Arvin
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Thanks for the photos of your caul DC. Much appreciated.
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Thanks for all the nice comments guys. I'm close, maybe the next two or three bows will do it. Getting into the mid 180's was fairly straightforward but the last 10-15 fps have been hard. I've struggled to keep from going underweight and not made it on most of the last four or five. For some reason I've found RD's to be difficult to tiller. Wider limbs for less set just adds to that problem. Thin limbs are tricky. This one was a compromise between DW and better tiller. I've had to rebelly a few because of unfixable hinges. I'm now running out of Boo and Yew. Maybe 3 or 4 more bows. Have to make the decision whether to order more or just pack it in.
Thanks
Don
Maybe get the Yew to approx size and the heat treat before glue up, that might give you some extra zip. Mind getting over 200 fps at anything under 45# is going to be a tall order IMO
Del
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I did that on this one but old age crept in. I lost track of what I was doing and glued the limbs to the riser without heat treating. So then I had to go back and heat treat but I was chicken to get too close to the riser glue joint. I'm trying to come up with a way to heat the entire limb piece in the oven at 350°f for a few hours or something so the entire belly is nice and solidly treated. The temp and time are to be determined. I could get a 29" piece corner to corner in the kitchen oven but that's just a tad too short. I may treat a piece and then splice on the recurves.
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Bad news. My scale has three options pounds, kilograms and jin. A Jin is a Chinese weight that equals 1.1023 pounds. My scale somehow got on "Jin" which is close enough that I didn't notice. So once I put it on "pounds" the bow weighs 42#, not 39#. This means my arrow was too light. True speed is 191fps. I'm bummed. I'm not sure when the scale got changed. I'm hoping it was recently. I thought this was too good to be true.
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I'm now running out of Boo and Yew. Maybe 3 or 4 more bows. Have to make the decision whether to order more or just pack it in.
Thanks
Don
Order more! You are an inspiration and you are also very very close!! No point in not ordering more!!
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Running the lam up the fades is the ultimate solution to handles popping off.
DC, did you steam and pre-bend the belly lams to fit up the fades?
It probably is the answer to belly popping and it allows you to use those short knotty pieces of Yew you can't throw out :D but it just seems to be one step further from primitive.
Fitting the pieces together is the drawback. It's not that easy. Maybe now that I've posted how I do it(further up) maybe someone will have a clever way to make it easy.
I can tell you how to make it 'easy'.....but it is much further from primitive :)
I was wondering what you have been doing differently....I made quite few bows like yours a few years ago, very similar profiles and was getting high 180's, low 190's. Pesky jins….
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Bad news. My scale has three options pounds, kilograms and jin. A Jin is a Chinese weight that equals 1.1023 pounds. My scale somehow got on "Jin" which is close enough that I didn't notice. So once I put it on "pounds" the bow weighs 42#, not 39#. This means my arrow was too light. True speed is 191fps. I'm bummed. I'm not sure when the scale got changed. I'm hoping it was recently. I thought this was too good to be true.
Dunno what you mean by your "arrow is too light"... it weighs the same as it did before you re-weighed the bow! ::)
IMO it's virtually impossible to make an arrow too light... if it's strong enough to withstand being shot it will be heavy enough.
Or do you have to reach some arbitrary gpp for some competition regulations?
Del
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It's just about the 200fps 10 gpp at 28" draw barrier.
DC , the good news is you're stronger than you thought. ;)
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Impressive. On the plus side you can continue chasing that elusive 200fps barrier. I think low to mid 190's is about as good as I was ever able to get
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IMO it's virtually impossible to make an arrow too light... if it's strong enough to withstand being shot it will be heavy enough.
Or do you have to reach some arbitrary gpp for some competition regulations?
Del
His bow is a heavier draw weight than than he thought ... he is chasing speed at 10 grains arrow weight per pound of draw ... so he now has to shoot a 420 grain arrow not a 390 grain arrow... that’s my take!
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Bad news. My scale has three options pounds, kilograms and jin. A Jin is a Chinese weight that equals 1.1023 pounds. My scale somehow got on "Jin" which is close enough that I didn't notice. So once I put it on "pounds" the bow weighs 42#, not 39#. This means my arrow was too light. True speed is 191fps. I'm bummed. I'm not sure when the scale got changed. I'm hoping it was recently. I thought this was too good to be true.
Dunno what you mean by your "arrow is too light"... it weighs the same as it did before you re-weighed the bow! ::)
IMO it's virtually impossible to make an arrow too light... if it's strong enough to withstand being shot it will be heavy enough.
Or do you have to reach some arbitrary gpp for some competition regulations?
Del
I check the DW and readjust the arrow weight every time I do anything to the bow to maintain 10 gpp. Just an arbitrary goal I set for myself. I suppose if I just changed my goal to 200fps@9gpp this would all be over. ;) ;)
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Impressive. On the plus side you can continue chasing that elusive 200fps barrier. I think low to mid 190's is about as good as I was ever able to get
Thanks Marc but since I've only been following your lead I don't know that I'll catch you. I'll be re testing the last ten or so bows this morning just to find out where I stand. I think it was just last week that I changed the batteries in my scale. It probably defaults to jin. I'll check that so I don't get caught again.
Just a sec.
No, it defaults to Kg. I must have pushed the wrong button. Anyway this is the scale. It's a great scale but if you have one watch out the Jins don't get you. They're on the right hand side of the screen.
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Thanks DC!!!
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DC what does the force draw look like on that style bow? Arvin
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I tested the last 6 bows I've made. I put a positive stop at 28". From where I stand the parallax was showing my weight a little less. That compounded the Jin problem. Reality check today. 5 of the 6 were just under 190. 187 was the lowest. This one was 193, double checked everything. It's only 36#@28". maybe you can tell me something about the FDC. I'm not sure what to look for other than a convex curve.
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I will do a force draw on a couple of bows Of different Weights. My curiosity is how if at all how they differ? Also can you math guys add up the total energy stored to predict better performance of one design over another. Using the whole force draw added together. Just asking. Arvin
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The total stored energy hints at potential but does not guarantee that it will all be delivered, nor the rate which it will be delivered at.
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Here's a 42# shoots 185fps. Definitely not as fat as the other one. This calls for a closer look.
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The total stored energy hints at potential but does not guarantee that it will all be delivered, nor the rate which it will be delivered at.
Yeah I wish there was a release FDC. ;) I guess, in a way, that's what the chrono is. I had one bow I was testing shot in the 190's and I realised that the arrow was too light, something like 10 grains so I changed tips to correct it and the speed dropped to 185 or something. Way more than I expected. I went back and forth a couple of times to check and the data was good. This bow reacted to a light arrow way more than normal. I have to go back and look at it again.
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Ok should it not loose the same pounds on release less the calculated arrow weight. And then I guess the weight of the arrow will affect the cast as the draw gets shorter. Where is the happy face pulling his hair out. :D Arvin
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Never mind my scratching. Maybe you can get a idea. These bows where all built on the same caul.
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It seems that the bows of different weights off the same caul has the same force draw only enlarged. Hummm
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That makes sense since your design is likely identical.
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Yes I noticed that. Pat I learning baby steps here . Arvin
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What did that caul look like Arvin?
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This
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Kinda looks like a curved caul makes a curved FDC and a straight caul makes a straight FDC.
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DC my force draw looks like one half of that caul. The flipped tips at the bottom of the force draw. Never done it full scale but I’m guessing it would be somewhat close. Arvin
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DC, I really like your hunt for that number...I´m sure you can do it. Glad you ask about so many things. Many interesting topics which I learned a lot from.
Thanks for doing this ....
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great work again DC - i once had some glueing problems when did a "belly lam over the handle"...glueing onto the "front side" of wood makes weaker glue joint imho. watch out, my last r/d also was 191fps ;D
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..glueing onto the "front side" of wood makes weaker glue joint imho. watch out, my last r/d also was 191fps ;D
I don't understand "front side". Good job on the 191. Are you shooting by hand or did you make a machine. I wonder if anyone is in the 190's without using an RD design. I've managed high 180's with a Molle but the tips were so skinny it gave me the willies to brace it.
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DC, normally you glue laminates parallel and also parallel to the grain - when you glue the belly lam up the riser block the glue joint runs up, across the grain. this gluejoint is weaker than same with parallel grain. ...and there is a lot of stress there. imho.
R/D design just works fine on wood as a material i think. I do shoot by hand, but only draw 26" as I dont get consistency on 28". The machine in our clubhouse still/again is under construction ;D
Can't find anymore this fdc but have one from a similar bow (same caul) might also post the bow
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DC, you are for sure a very serious bow builder. I hope some day you reach your goal. In the mean time it is fun watching your posts, and the speed you get on your all wood bows are awesome.I am thinking you spend a lot of time in your shop.
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A reflexed static will almost certainly shoot faster for at least a few shots.
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A reflexed static will almost certainly shoot faster for at least a few shots.
PatM, the tips on Dons bows seem to be static.
can you post a pic of a limb you consider "relexed static" please?
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DC, normally you glue laminates parallel and also parallel to the grain - when you glue the belly lam up the riser block the glue joint runs up, across the grain. this gluejoint is weaker than same with parallel grain. ...and there is a lot of stress there. imho.
R/D design just works fine on wood as a material i think. I do shoot by hand, but only draw 26" as I dont get consistency on 28". The machine in our clubhouse still/again is under construction ;D
Can't find anymore this fdc but have one from a similar bow (same caul) might also post the bow
You got 191 with a 26" draw????
Oh thanks I understand the end grain thing. What are you going to do. It has to be glued like that. Trust in epoxy ;D
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DC, you are for sure a very serious bow builder. I hope some day you reach your goal. In the mean time it is fun watching your posts, and the speed you get on your all wood bows are awesome.I am thinking you spend a lot of time in your shop.
Thanks Bassman. I spend most of my time in the shop. I babysit my grandson in the summer so I don't get as much time out there then. I'm pretty much a hermit so social things don't get it the way and I'm blessed with a very tolerant wife. When I pick a hobby I kind of get obsessed and don't do anything else.
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Smik what is as the arrow weight you shot from the 55# bow in the force draw? Arvin
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great work again DC - i once had some glueing problems when did a "belly lam over the handle"...glueing onto the "front side" of wood makes weaker glue joint imho. watch out, my last r/d also was 191fps ;D
No not at all.
If you prep everything right and execute it all correctly gluing the belly lam up the riser ramp is by far the best way to go. It is a much more complicated procedure than just gluing a chunk onto the belly of the handle area...but it is bombproof.
There is a reason virtually every glass bow is made this way :) and it isn't because it is weaker!
DC to get yourself closer, here are a few things to try.
More deflex built into the riser. (reference Adam Karpowzi's d/r bows) Reflex the whole limb, tiny bit inner limb, increasing as you progress along the limb towards the recurve. Make your bows tri-lams (walnut or similar core) and use a two step glue0up with as much perry as you dare. Also trap your bow so it is about 3/4 the width of the limb,e especially inner/mid limb, fade out the trapping a little towards the tips. Use as thick but narrow a recurve as you dare, I've gone narrower than I though possible before....doesn't make for the sturdiest bow out there but good enough. You can also splice in stiff wood recurves. Or go the laminated route, these are super strong and can be reduced further than a regular tip, the gluelines add virtually no weight. No heat used either so the wood is still at full strength.....
Good luck.
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DC:
You got 191 with a 26" draw????
Yes, it's a little while now and I decided better not to post about it 8)
Arvin: Smik what is as the arrow weight you shot from the 55# bow in the force draw?
This is the fdc from another bow that blew up when I took it to 28" for fdc (glueing problem) (pic 1). I never checked fps on this particular one as it was too heavy for me to shoot consistently. The 191fps was a 358gn arrow at 36# @ 26" on another bow, same profile (pic 2). Same profile on a third bow got me 186fps @ 33# with 330gn arrow @26" - this bow has different, less aggressive, tiller. Tillered a little more to an arc (no pic).
bownarra: could be - I had my problems and a friend of mine - a timber construction engineer - told my the endgrain thing.
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The 191fps was a 358gn arrow at 36# @ 26" on another bow, same profile (pic 2). Same profile on a third bow got me 186fps @ 33# with 330gn arrow @26" - this bow has different, less aggressive, tiller. Tillered a little more to an arc (no pic).
Simk, do you have any pics of the unstrung profiles?
thanks.
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willie:...the lower one...
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That extra 2" would make quite a difference. You should make your own machine. It wasn't a big job.
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DC to get yourself closer, here are a few things to try.
More deflex built into the riser. (reference Adam Karpowzi's d/r bows) Reflex the whole limb, tiny bit inner limb, increasing as you progress along the limb towards the recurve. Make your bows tri-lams (walnut or similar core) and use a two step glue0up with as much perry as you dare. Also trap your bow so it is about 3/4 the width of the limb,e especially inner/mid limb, fade out the trapping a little towards the tips. Use as thick but narrow a recurve as you dare, I've gone narrower than I though possible before....doesn't make for the sturdiest bow out there but good enough. You can also splice in stiff wood recurves. Or go the laminated route, these are super strong and can be reduced further than a regular tip, the gluelines add virtually no weight. No heat used either so the wood is still at full strength.....
Good luck.
What would be the advantage of a tri lam? Is it just the lighter limb or does the slightly different grain direction do something. I've been trying to avoid the complication of another layer although on the bows I've had to rescue with a belly lam I seem the get a few fast bows.
I've thought about trapping but the limbs are so thin(approx .375") that I didn't think it would buy much. I also thought that the belly edge radius would get awful sharp. If you used the old radius of a pea for the corners there's nothing left of your trapping.
If I were to use a laminated recurve should I just "V" joint it on. Is it necessary to run the backing right up the recurve or could I stop it at the splice? Due to an elderly moment I seem to have a nice pair of bamboo backing strips that are about 2" short. :-[ :-[
Thanks for the hints :D
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Speaking of gluing things, I heat treated both sides the belly strips quite aggressively. They are dark brown/light black. I was just wondering if that would affect the glue joint? I've already glued the belly strips to the riser so that ship has sailed but I still have to glue the backing on. Any cautions I should take?
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If you prep everything right and execute it all correctly gluing the belly lam up the riser ramp is by far the best way to go. It is a much more complicated procedure than just gluing a chunk onto the belly of the handle area...but it is bombproof.
Exactly. The glue joint doesn't have to be as strong because the stresses ride up the belly lam over the handle instead of following the glue line under the handle and popping it loose.
Or go the laminated route, these are super strong and can be reduced further than a regular tip, the gluelines add virtually no weight.
Do you have a preferred or recommended wood for laminating into tip recurves?
bownarra: could be - I had my problems and a friend of mine - a timber construction engineer - told my the endgrain thing.
Your friend is correct that endgrain glue joints are weaker. This is overcome by the fact that running the belly lam up the fades is a far better way to transition into a stiff handle than gluing the handle onto the belly surface. You get a somewhat weaker glue joint, but a much lower stress concentration at the fade.
I also thought that the belly edge radius would get awful sharp. If you used the old radius of a pea for the corners there's nothing left of your trapping.
The belly side doesn't really need much of a radius at all. Even on the back the radius of a pea guideline is way more than necessary. I have been radiusing the back corners about 0.080" and on the belly I just break the sharp corner with a couple swipes of a sanding block with 120 grit paper.
If I were to use a laminated recurve should I just "V" joint it on. Is it necessary to run the backing right up the recurve or could I stop it at the splice?
Should be no different than siyahs, should it not? I would run the backing over the tip of the V on the splice, but it doesn't offer much help beyond the splice if the laminated piece is made stiff enough on its own.
Mark
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I would run the backing over the tip of the V on the splice,
Mark
Now there's a thought. As long as I can remember it. ;) ;) Thanks
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More deflex built into the riser. (reference Adam Karpowzi's d/r bows)
Is this in his Horn Bow book? Where might I look?
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MMattockx has answered the questions well :) Thanks :)
The tri-lam route lets you build in a prestressed eg perry reflex glue-up. Do the glue-up in two stages. Belly and core, then add the backing. It is more messing about but that is what you will have to do to get the 200fps. You've re--awakened my interest in it too haha, I haven't built any bows like I describe for a while now b ut maybe I will :)
You can have a spliced in recurve with nothing 'protecting' the splice - no problem. I've done it many times and yes a simple v-splice.
Why heat treat both sides of the belly lams?
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I was trying to get the heat treat as deep and even as I could. I'm not positive but I think I've scraped though the heat treat a few times.
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Another reason for the tri-lam approach is that it isn't too hard to get your recipe and stack info dialled in.....so tillering is only a bit of tweaking to get to full draw and take account of any funny bits of wood:) Leaving you with a full heat treated belly.
Do you have a drum sander for lam prepping?
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Another reason for the tri-lam approach is that it isn't too hard to get your recipe and stack info dialled in.....so tillering is only a bit of tweaking to get to full draw and take account of any funny bits of wood:) Leaving you with a full heat treated belly.
Do you have a drum sander for lam prepping?
That is a couple of the reasons I'm shying away from tri lams. Keeping detailed records and pretty much building the same bow over and over are not really my thing even though my boo yews are pretty similar to each other. We'll see.
I have a cobbled up thickness sander I assembled on my metal lathe. The drum is one of those compressed rubber things that is a bit out of round and a bit concave. I could turn a solid drum I guess.
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MMattockx has answered the questions well :) Thanks :)
The tri-lam route lets you build in a prestressed eg perry reflex glue-up. Do the glue-up in two stages. Belly and core, then add the backing. It is more messing about but that is what you will have to do to get the 200fps. You've re--awakened my interest in it too haha, I haven't built any bows like I describe for a while now b ut maybe I will :)
You can have a spliced in recurve with nothing 'protecting' the splice - no problem. I've done it many times and yes a simple v-splice.
Why heat treat both sides of the belly lams?
Do you have any braced and FD pics of this bow? How did it shoot? That stuff :)
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I could turn a solid drum I guess.
I recently saw online somewhwere, a homemade thickness sander that had a turned drum that utilized an off the shelf smaller belt sander belt. 6-7/8" diameter possibly, would have to find the post or article again to verify that diameter.
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I've looked at a bunch of videos. What was holding me up was how to anchor the ends of the sandpaper strip. Looks like a lot of them just screw it on and don't use the part of the drum where the screws are. A simple solution like that never occurred to me :-[ I've got about a half dozen sanding drums for the rubber thing. I was waiting for them to wear out but I'm still on the first one. Best sandpaper I've ever seem. If I could figure a way to attach the sanding drums to a solid drum. I guess if the drum is going to last that long I could just glue it on and make a new one when it wears out. I always seem to think of the solution while I'm typing. Great think this forum ;) ;)
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More deflex built into the riser. (reference Adam Karpowzi's d/r bows) Reflex the whole limb, tiny bit inner limb, increasing as you progress along the limb towards the recurve.
Bownarra, you can see the amount of deflex in the pic of the jig. It's right around 10°. Then when I glued it up and reflex the limbs the bow looks almost straight. In this case would you say there is any deflex? Would you add more?
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I would say you need a fair bit more. I can't remember the angle I used on my fastest recurve but will measure an old bow.
Basically I wouldn't want the tips of the glued up bow to be anymore than 2" in front of the handle .
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Basically I wouldn't want the tips of the glued up bow to be anymore than 2" in front of the handle .
Is this because you would overstrain the wood and it would become a case of diminishing returns?
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I would agree with more than 2” in front handle it’s hard achieve low set wood bows. But there is better tiller bowyers out there. But that’s about as far as I have been able to push the limits. Arvin
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Basically I wouldn't want the tips of the glued up bow to be anymore than 2" in front of the handle .
Is this because you would overstrain the wood and it would become a case of diminishing returns?
Yes.
18 degrees.
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Also re--read the chapter on the Wilcox Duoflex. When tillered right these are smoking fast. All the ones I've seen have been tillered as a regular bow so you don't get the initial hump on the f/d curve.
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All the ones I've seen have been tillered as a regular bow so you don't get the initial hump on the f/d curve.
I don't understand? You can tiller for the hump? How?
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DC, you can pick up some extra speed by shortening the working area in your limb but you have to add quite a bit of width or loose the benefits to set.
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Thanks Badger, I did try widening a few but it just made tillering worse I have noticed that if the outer part of the limbs is stiffer the bow seems faster. Saying the same thing in a different way I guess. I have to get my tillering better that's all there is to it.
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By making the 'inner bow' thicker than normal. it explains it all in the TBB.
If your outer limbs are stiffer then you are concentrating the bend closer to the handle.
By doing this the tips return path is longer AND the inner limb is thicker. It is thicker because it is being acted upon by greater 'leverage' and thicker limbs have a natural faster return speed than a thinner limb. Of course set trumps all :) A gain somewhere means a loss somewhere else normally....