Primitive Archer
Main Discussion Area => Bows => Topic started by: Marc St Louis on February 26, 2008, 06:51:20 pm
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I started working on this bow a few years ago but it was aggravating and I had to leave it for awhile. It's patterned after the Wilcox Duoflex bow he developed in the 1930's and is made from HHB backed with White Ash. The limbs had a serious lateral stability problem that made me nervous tillering it out. Then last month I had an idea on how I could continue, it was nothing more than a matter of shortening the limbs by an inch. This took the reflex down to a manageable amount and this took a lot of strain from the limbs. I still haven't finished with the bow but do have it tillered out and I thought I would post some force draw numbers on it. The bow turned out at 57# @ 28" with a very smooth draw. Here's the force draw on it
10" = 18#
12" = 23#
14" = 28#
16" = 33#
18" = 38#
20" = 42#
22" = 45#
24" = 49#
26" = 53#
28" = 57#
What created the problem initially was that I had put in about 5" of reflex in the bow. Cutting 1" from the tips reduce the reflex to about 3", this still left the bow at about 60" in length and after tillering to 28" still has a couple inches of reflex. I haven't shot the bow yet as it's not ready for that but I suspect it will have excellent performance. Here's a picture of the bow as it is now
(https://i.imgur.com/LlW8FlQ.jpg)
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Nice bow Marc. Justin
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Interesting bow. I'm surprised it has decent early weight, looks almost the same shape braced, as unstrung. When does the string lift off the limbs? I'd guess between 18 and 20", thats when your pounds per inch of draw drops a bit. Your experience is like a lot I've heard about, you get much more than 3" of reflex and its diminishing returns on these natural materials bows. Really nice work. Did you glue all the reflex in as forced reflex or did you heat-form it some?
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i've wanted to do one of them.please answer tom s questionas it applies.i'm a newbie comparerd to you all,but ... nice marc. tom
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Mark, some of us will be waiting patiently for your chrono tests, at 75% efficient it could easily shoot 10 grain arrows over 190 fps. very good possible candidate for the first bow to hit 200 fps at 10 grains arrow weight. Stored energy is phenominal. Efficiency will be the big challenge from this point on. From appearances it looks like it will be equally efficient. Also congratulations on successfully building an extremely difficult design. Steve
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awesome project. i'm with badger,except i can hardly wait for the results ;D
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Looks nice Marc. I like the duoflex. I bet it's tough to get those curves to open up properly. Look forward to see it finished.
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looks great so far, i look forward to seeing it aswell- Ryan
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Wild looking bow Marc! I still don't know much of anything about efficiency, cast and such - this will be interesting. Am thinking about trying something new (to me) with my next one :).
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Marc,
Very nice love the look of that profile!!! :o
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It was interesting tillering this bow out. The brace height of the bow is 6"
I think you are right Lennie. I have a picture of the bow drawn to 22" that I took to examine the tiller as I was tillering that I will upload. The string has already lifted from the recurves. I started this bow 3 or 4 years ago so you are asking a lot for me to remember that far back. I think it was a combination of heat and glued in reflex.
I half expected this one to blow on me. I tried one like this out of BL before making this one and it failed violently. It could still blow as the limbs are highly stressed
(http://i.imgur.com/g7pdEbl.jpg)
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What a challenging design, you have done well to get it to this point Marc. I hope the wood can handle the stress.
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Wow, that is a challenging design. Did the lateral stability issue ever cause any frets to appear along the edges?
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Cool looking design Marc. It kinda look's like the Bear Kodiak Magnum. Looking forward to seeing the finished results.
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I'm impressed I think that string angle is less shocking :)I meant that in a good way, nice job.
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WOW! - can't wait to see thisone finished!
i believe your bows (especially your recurves) are really recognizable by their style eventhough i never saw one for real; you left a strong mark on them, so to speak... ;D ;D ;D
frank
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Mark, if you just wanted to get a feel for the efficiency of the bow before its finished ( just in case it breaks) you could take some shots through a chrono at a shorter draw length. As long as you know the draw length you were at and the draw weight and arrow weight the efficiency will stay about the same and we could project out the speed. Steve
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The only wood I have my doubts about is the Ash backing Dano. I did pick about as good a piece as I had on hand.
That wouldn't cause frets Gordon and HHB is a very elastic wood.
I do that anyway Steve. It's a bit cramped in the house right now to be shooting through a chrono :)
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Compliments Marc!
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Nice bow Marc, love the profile of that one.
Alan
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i have a piece of osage heated and bent into a similar shape. as soon as i find the time i'll glue some boo onto the back of it. can't wait to see your bow cranked back to 28"!
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Where do the limbs work in the last 6" of draw Marc, middle or outer?
That one looks like it it still working in the inner limb at 22".
Beautiful bow.
I remember when you were in the super-deflex in the handle stage. It inspired a couple of my projects. I have always had a very difficult time getting pronounced r/d to come around in the middle and outer limb, typically having a flat or straight limb at full draw. I have learned since that a bow which works a good bit in the inner limb w/ a relatively straight outer limb can be very effective, particularly a shorter bow.
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I'd like to see some of these deflex in the handle bows, am thinking about giving that a try..
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Looks very good so far Marc,on a challenging project.Bet it will spit and arrow. :) I couldn't
stand it,I would have to shoot it. :)
Pappy
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David
I try to get them working right through to within 4 or 5" from the tips. Very little work being done in the outer limbs though.
I don't shoot anything till it's time Pappy :).
Here is a link to some of those highly deflexed bows I have made Paul. http://marc.stoneflake.net/Bows%202/Dream%20Weaver/Combo.jpg http://marc.stoneflake.net/More%20Bows/Hickory%20backed%20Osage/Combination%20Pic.jpg
Here's is a picture drawn to 26", you will have to wait for 28" draw till the bows is all done
(http://i.imgur.com/zILyFZ5.jpg)
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B E A U T I F U L !!!
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You got everything needed to hit 200fps @10gr. and 28" Marc, and having a close or center-shot shelf can be good for a few fps as well. Looks great!
Rich
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Looking sweet Mark, I really like the D/R profiles. Cant wait to find out how it performs for you. Keenan
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(http://www.woodlandarchery.com/images/legolas5.jpg)
Your bow looks strangely similar to this bow from the LOTR trilogy ;D Bet they copied you though hehe
The bow is very nicely made and looks very fast! BTW are you canting the bow a bit in that pic? Maybe its just me but the top limb looks like its bending slightly more. ???
-Alex
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thats awesome marc
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Alex
The bow has 1/8" positive tiller now but it did have almost 1/4" in that last picture.
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Thanks for posting those Marc. Those are some tough looking bows! Maybe I should get a few more regular recurves under my belt before I give that a go :).
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I do have another one I have been working on. It's a Hickory backed Osage. It was also giving me headaches so I put it aside a couple years ago. It's about time I get back on it
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awesome, impressive, can't think of the propper word. first thought was: who needs glass, when you see a bow like this?
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Mark, I have a hickory backed osage that is similar been setting around for a few months now, not quite as radical but you have me thinking about it. Steve
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Mark, your work inspires us all. Can't wait to see how fast it shoots. Hope it holds for you. Danny
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Steve
I like Hickory and Osage. Makes a good combination, better than Bamboo and Osage IMO. You should go to work on it and finish it up
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Mark, working recurves have always given me fits. I just don't have the skill you have with them. I went and looked at it and decided to wait till I am really feeling extra patient That stored energy you are getting is just blowing me away. I have done a few in the past semi successfully but htere was always something or other wrong with them. Ironicaly the first bow I ever built that didn break looked just like a wilcox duoflex, 3 laminations. I had tapered all three laminations and just glued it together, not a clue what I was doing, no tillering just cleaned it up and shot it. I just got lucky LOL. I am anxiously waiting to see how yours comes out. Steve
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(http://www.woodlandarchery.com/images/legolas5.jpg)
Your bow looks strangely similar to this bow from the LOTR trilogy ;D Bet they copied you though hehe
The bow is very nicely made and looks very fast! BTW are you canting the bow a bit in that pic? Maybe its just me but the top limb looks like its bending slightly more. ???
-Alex
This bow is simply cool. I love the round belly bendy handle version of the LOTR but I think it was rubber. I don't think I could get this form in a bow that fille dout the handle with out building up and be under 1000lbs. Not in Ipe or Hickory anway. Maybee hickory but not as thick and bulky as that bow.
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Very impressive Marc! Does ash have a stronger back than hhb? I've noticed you like to back your hhb with ash so I'm assuming that's the case or is there something else you gain from it? Awesome bow and looking forward to the final results!
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Excellent work, Marc! Jawge
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WOW! :o
This topic is over four years old!
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this will probably set record for the oldest topic still at the top of the menu :) nice bow!! can't wait to see it finished
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SWEETTT
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Marc: Your handle designs on these always intrigue me, and i can't get my mind to wrap around just how you get that done. Are there any threads where you elaborate on this? If not, could ya? ;D
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Very nice Marc, been woreking on something almost identical.
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so...it has been 11 years... how did that bow turn out? ...and the hickory backed osage? I do like the sound of that wood combination.
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Awesome bow Marc. I'd like to see how you splice your handle to. I've got a bunch of billets now and I've been wanting to attempt this design for quite some time.
Bjrogg
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By the way 18,026 views is pretty impressive thinking I'm not the only one interested in this bow
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thats a nice one,, thanks for posting and sharing the progress
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How thick would you make the hickory backing, and from heartwood or sapwood? I have an Osage in progress that I am sure will need backing.
Hawkdancer
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The HHB chrysalled after awhile so a more elastic wood would be better in this design but it sure was a fast bow. I think a Maple backed Yew in this design would be awesome.
I don't like Hickory as a backing, much prefer Maple. I always make the backing 1/8" thick unless the bow is more than 80#
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Maybe that's what I need to get my a$$ back in the shop. I've got some yew and some maple. I've also got bamboo which I prefer for no reasonable reasons. I tried kinda that much reflex with a plum selfbow and almost all of the reflex pulled out. if I glued it in it might hold. Think I'll print out those pictures and tape them to my tree :) :)
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Why can't you shoot the bow if its fully tillered to 28" ?