Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: bowhunter15 on September 21, 2015, 02:15:00 PM
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For anyone didn't follow my last build-a-long on here, it was a big success thanks to the help of people on this forum. It was a 68" R/D BBI. I may make another one to trade to a friend of mine for a nice shotgun.
For my next personal bow, I want to go short. I see designs of bows 54" to 58" that look intriguing, like the Big Jim Thunderchild, Super Shrew, Cari-bow Wolverine, etc. The reason is I want a bow that's easier to maneuver in my typical tree stand setups. I can make the 68" work, but often find the string hitting my thigh on close shots.
It appears that most of the bows I've listed are made of glass and wood laminates, with forward handles, a bit of deflex, and lots of reflex. Is it possible to make an all wood bow like a BBI or BBO with similar dimensions and 60-65# @ 28"? If not, would it be possible with a tri-lam? I'm guessing the amount of pre-glue bending that an osage or ipe belly can withstand is somewhat of a limiting factor. Can a short bow be made asymmetrical, or should the handle be centered to maximize the working length of the lower limb?
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Yes to bbo... and yes to tri-lams. I've done it 56-58" long with bamboo and Osage, 60-70#@28", shorter bottom limb. Deflex/semi-recurves are especially nice for this application.
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Originally posted by Bowjunkie:
I've done it 56-58" long with bamboo and Osage, 60-70#@28", shorter bottom limb.
That may be what I try then. Any change you have a build along for that one? I see 3 Rivers has osage boards on sale right now, but they are 5/8" thick. I imagine they'd need to be tapered, which is something I don't yet have the best tooling for. Could get close with a bandsaw/beltsander and tiller from there I suppose.
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Here is a 66" build, just make yours shorter..
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=012149#000000
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Are those parallel lams that you started with or tapered? Seems like when I look online, you can either find full length parallel lams up to 0.060" thick or tapered lams at 36" long, which obviously wouldn't be right for this type of bow.
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My bows are all wood. The belly lam is parallel, core lam is tapered from 1/4" thick at the riser to 1/8th thick at the tips. I start out with 36" long everything. Depending on what length bow I want, I just cut some material off the riser end. These lams also need to be Z spliced together. So that will shorten the 36" up by 4 inches.
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You can go pretty short, but you need to go wider if you're gonna try and keep the draw weight up. FWIW a really well made 40#er is deadly accurate and will kill deer just fine.
Here are two I built. Both forward handle, almost all mine are. The 40#er shot 140something FPS with a 500gr arrow at 25-26" draw. Not a rocket, but easily comparable to most 50# selfbows, certainly the dog-ish selfbows I have built lol.
Ipe is pretty good stuff, but in my opinion probably shouldn't be made narrower than osage.
Both these bows are pretty wide at 1.75" at the fades.
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=012112;p=1
http://tradgang.com/noncgi/ultimatebb.php?ubb=get_topic;f=125;t=011930;p=1#000000
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I have a 54" horn bow that's no wider than maybe an inch. The design doesn't seem to need bent and spliced siyahs, just a core lam with thicker ends, horn and sinew. Pulls about 50#@28", easily handles 32". Might be worth looking at. Weighs nothing as well...
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LittleBen, based on the pictures of your bows, it looks like you glued up the core and belly first, then added the tapered handle pieces, then glued up the backing strip over everything. Is that correct? Looks really nice.
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Rule of thumb for wooden bow length is drawlength x2 = 4inch handle and 2 inch fades = 64 inch.
Making a bow a tri lam instead of two lams won't help in getting more draw length.
Halfseminole has a point about making a hornbow but have you got a couple of years to get a handle on making them!?! You could make a Turkish bow at 42 inch for a 28 inch draw. :)
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Originally posted by bowhunter15:
LittleBen, based on the pictures of your bows, it looks like you glued up the core and belly first, then added the tapered handle pieces, then glued up the backing strip over everything. Is that correct? Looks really nice.
This is how I term the parts from back to belly side:
Backing, riser, core lam, belly lam and handle block. Everything except the handle block gets glued up together, then the handle block is glued on once the bow comes off the form. But you could do it in multiple steps if that makes it more manageable.
Also, all the lams were tapered to .002" before glue up. This doesn't give you a lot of room to belly tiller though so I'm hesitant to recommend this approach. The stack thicknesses im using are very specific to limb length, amount of reflex, and side profile (r/d).
@Mikekeswick, maximum draw on these bows is approximately 110% to 120% of limb length. So 58" bow - 12" riser = 46"/2= 23" limbs for up to 26" draw. The lighter bow is closer to 60" but with a 14.5" riser. I haven't torture tested wither so they might survive more draw but who knows.
They are relatively wide (1.75") thin (<.5") limbs, and have the side profile to reduce stack.
I wouldn't be so bold on a straight limbed bow, and I would warn the OP that although it can be done, these were not 28" draw bows and they weren't my 2nd or 3rd or 20th bows.
Give it a shot, but stick with it if the first try doesn't turn out. At the same time, your first was great work so I have faith you can pull it off.
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you got some pics of that bow ED
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http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=125;t=011195;p=150
Last pic on the page. Need to spin it a new string.
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Hmmm, guess I'm making bows I shouldn't be makin ;) Best part is, they're the best I've made.
Yes, I did a build-along on another forum. I'll see what I can dig up when I get home.
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Rule of thumb for a straight limbed bow! Nothing in this game is set in stone ;) I've made plenty shorter too but you just get closer to the limits - I guess it also comes down to what your precise requirements are too. Adding deflex out of the riser will certainly allow for a longer draw. Wider, thinner limbs can bend further. Highly elastic belly woods will allow more bend without excess set. The list goes on and on....but a general rule of thumb is still a useful thing.
The easy way to make a short wooden bow is make it bend (a shade)in the handle and sinew back it.
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Maybe that's the easiest answer ... A bendy handle bow would make that draw and length no problem.
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Mike, I didn't think we were in a discussion relegated to straight standing bows. That would surely change things.
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Jeff, quit yapping and start posting some of your RD bows! Lol This guy wants to see what's basically the ambush bow!
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(http://img.photobucket.com/albums/v312/Jeff_Durnell/Raven/BYO60_zpsd31a6ff1.jpg)
Here's a profile that will allow you to do what you're asking. This is a tri-lam. Bamboo back, yew core, and osage belly. 58", 57# @ 28", asymmetrical. It's 1 1/4" wide. I've done the same thing with various profiles, hybrids, full recurves... and some very similar with two piece layups. i.e. boo-backed osage.
I kept this one relatively short in the handle area to maximize working limb length, while maintaining the stiff handle section. It has a 4" handle, 1.5" flares, and 1.5" fades for a total of 10"... and it's actually a little less than that after the dips were finessed.
I have a full build along of this bow, but posting pictures on this site is a pain :(
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Nice profile on that bow Junk. ;)
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Yep Ben, basically ambush bows. I was just fondling this one as I was taking measurements and holy crap she's a little temptress... just BEGGING to be hunted with. Had a lot of bows speak to me, but none thataway. Probably the best-balanced bow I've ever held, and best balanced I've shot. But when I hunt, it's selfbows I carry. I'm cursed :rolleyes:
Ya know I might... might, consider taking her to the mountains in a couple weeks. For what I'm doing, she's actually perfectly suited in all ways.
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I tried posting more pictures but my computer is old and tired and photobucket isn't jiving with it. Sure wish we could post pictures directly here.
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I guess it's ok uncle bow junk... LMAO :)
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Cool, so I think I've got a pretty good start with shape and construction now. For wood choices, I want to do bamboo and osage for the back and belly, however, I really like the contrast in the core and handle like the bows that Ben posted. I found that there's a couple stores near my place that stock exotic and domestic boards in 1/8" thicknesses. I want a nice dark wood to contrast the lighter back and belly, and complimenting the yellow of the osage would be a plus.
The woods I like on their site are: walnut, padauk, purpleheart, bolivian rosewood, katalox, and wenge. Would any of those work just fine for core, tip overlay, and possibly riser? Seems like they range from medium to very dense. The purpleheart might give it sort of a Minnesota Gophers theme. Gonna have to buy some colored pencils and start brainstorming how I want everything to look lol.
This will still be a bit down the road. I haven't bought a sander or band saw yet.
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I'm thinking maybe a profile like this?
(http://i83.photobucket.com/albums/j308/teenathlete3030/Longbow%20Profile_zpswqlfktuj.jpg) (http://s83.photobucket.com/user/teenathlete3030/media/Longbow%20Profile_zpswqlfktuj.jpg.html)
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Profile looks good. But I can assure you a riser as thick as pictured is a recipe for trouble.
I would shy away from the heavier core materials. It's not life or death, but walnut is going to give better performance than wenge for sure. Cherry or maple also look good and work well as a core.
FWIW, if you don't already own the core material it might be worth just buying a pair of laminations which are already ground to a taper like .002. It's not critical because you're going to have to tiller it anyway, just means a little less scraping. A set of walnut (or other domestic wood) tapers shouldn't cost much ... Maybe $10-20.
Generally core materials should be light, and riser materials and tip overlay materials should be very strong.
If you use a relatively thick riser like I do, you need to REALLY REALLY make sure the fades are ground very smoothly down to PAPER THIN! If not you will get hinging at the fades. You can hedge your bet a little by ALSO adding a very thin (maybe only .125") power lam maybe 3-4" longer than the riser. With a riser like that it would also be wise to use a gap filling glue like Urac or smooth-on.
I might recommend a riser of 10-12" and a very thin power lam of say 14". But others might have other ideas.
Lastly, adding a thick riser like that is a bit of a challenge in itself to get right. It might be worth considering just building this one the way you built the first one in terms of riser, and focussing on a clean tiller since the bow will already be much shorter and thereby more challenging. There's always next time to add more complexity.
Sorry for the essay ...
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Thanks for the essay. The riser is deceptive in its thickness I believe. I drew it so that its depth from the belly to the deepest part of the handle is 1 5/8", which is exactly the same as my last bow. The difference is, my last bow had the handle entirely on the belly side and no riser (similar to Bowjunkies pic too) whereas this one is more "forward handle" in design. Do you think that if I simply shifted that entire region towards the belly (meaning less riser thickness and more handle thickness) that would help and make it easier to build? The only reason I was thinking forward handle was to model it after other short bows on the market. It's my understanding that forward handle is more forgiving, but standard handle is faster because of the brace height differences. If the riser is longer than the handle, doesn't the riser itself act as a power lam? I could split the riser into multiple pieces instead of one big block.
I've got no issues with ordering tapers. Looks like Bingham has a decent selection in the $16-23 range + shipping unless anyone has other vendors they like. I found a post by Bowjukie from a couple years ago:
Posted by Bowjunkie (Member # 482) on July 20, 2011 07:26 AM:
I've used cherry in glass bows as well as backed them with hickory. I love that stuff... works easily and doesn't load up or dull tools, not oily and glues up and finishes readily, very pretty flat grain under clear glass(sometimes looks a lot like yew), diffuse porous rings with moderately closed grain, readily available. No problem with weight, it holds it's own. The last cherry glass bow I made was 70# @ 28", as predicted.
In selfbows or backed all-wooden bows, it's barely acceptable in my opinion. The good thing about THAT is, it will force you to refine your design and tillering skills.
I haven't done it yet, but I'm guessing it would be the perfect wood to put between boo and osage in a tri-lam.
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I was just wondering how many bows you've made?
Is this your first foray into this sort of design?
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Garrett, yes if the riser is longer than the handle it acts as a powerlam. The reason I suggested an additional power lam is because grinding out the fades of the riser can be a bear to get right. A thin powerlam in addition which is longer than the riser helps smooth the transition into the bending limbs.
And yes you could just shift it towards the belly side.
I only made the point about the thickness of the riser because I've built many like this and it is a real pain.
I think you need to take one step at a time. Build a short bow first, then add then complication of the fancy forward handle later on another build.
That's just one man's .02
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Originally posted by mikkekeswick:
I was just wondering how many bows you've made?
Is this your first foray into this sort of design?
I've made one 68" R/D BBI. First attempt at a tri-lam or a shorter bow.
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Originally posted by LittleBen:
Garrett, yes if the riser is longer than the handle it acts as a powerlam. The reason I suggested an additional power lam is because grinding out the fades of the riser can be a bear to get right. A thin powerlam in addition which is longer than the riser helps smooth the transition into the bending limbs.
And yes you could just shift it towards the belly side.
I only made the point about the thickness of the riser because I've built many like this and it is a real pain.
I think you need to take one step at a time. Build a short bow first, then add then complication of the fancy forward handle later on another build.
That's just one man's .02
Okay, would you still suggest a power lam anyways if I move the handle all to the belly side? Something a few inches longer than the handle between the backing and core, .125" in the center down to a feather taper, made of the same hard wood as the bulk of the handle? I need to have some protection from the handle popping off. My last bow had fades build into a thicker 8" center that I glued the handle onto.
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Yes to the power lam. I'd probably go thicker than .125" in that case though. Maybe 1/4" ....
Anyone who uses a lot of power lams wanna comment?
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Makes sense LittleBen to use the power lam.
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Another quick question... if I have the belly lams stay on the belly side of the handle, as shown in the sketch below, would I still need a power lam or are those two options basically there to solve the same problem?
(http://i83.photobucket.com/albums/j308/teenathlete3030/IMG_20151118_223726_zpsemyqt25g.jpg) (http://s83.photobucket.com/user/teenathlete3030/media/IMG_20151118_223726_zpsemyqt25g.jpg.html)