Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: LittleBen on October 15, 2012, 09:04:00 PM
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Hello to all my fellow bowyers here on TG. I decided to try and do a little build along. I'll do my best to fight my inherent laziness and actually post photos as I work.
I'm building a 3 piece takedown recurve bow, I'm shooting for something wround 64-66" ntn and maybe 40-50lbs. The limbs will be Hickory backed Jatoba, 1.75" wide at the fades and tapering to 1/2" tips. The riser will be laminated Jatoba thinwood and probably some figured maple or laminated hickory thinwood on the belly side of the riser. Probably going to do 10-15 degrees deflex of the limb pockets.
Here are some pics of the recurve form I just finished, as well as some pics of the limbs just off the forms.
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-48.jpg)
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-49.jpg)
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-50.jpg)
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-51.jpg)
To make the limbs: first I steam bent each of the hickory backings to the form and let them cool and dry, then the same for the jatoba. Then I laminated the pre-bent lams on the form using TBIII. Form is thoroughly oiled so that the glue wont stick much. FYI the hickory backing is 3/16 and the Jatoba is also 3/16.
To make the portion of the limb which will attach to the riser thicker I will cut 6" from the base of each limb and laminate that piece on the belly side so that its layared Hickory-Jatoba-Hickory-Jatoba and then taper them over the last 3" to fade into the limb. (Pics to come)
Since I did not use any tapered laminations I will need to thoroughly tiller the limbs once the bow is assembled. I intend to remove wood form the belly and backing side of the limbs to maintain the 1 to 1 ratio of backing to belly wood.
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Forgot to mention. Unfortunately the hickory has a large amount of grain runoff. I figured I wound just give it a shot, anyone have experience with poor quality hickory failing due to grain runoff?
Maybe I will have to back it again. maybe I could use really thin edge grain maple or something, or really thinned out good hickory. Any thoughts? I guess theres always sinew ..... or rawhide?
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Pretty cool- I'll be watching this one!
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That looks like something I'd like to try too. I'll be watching.
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my first hickory board bow, had bad run off on the bottom limb- possibly a growth ring runout about every 3 or 4 inches.
it is still shooting well to this day- many many hundreds of shots- and i geuss i can now say that the tiller was a little( ahem!!) less than perfect- beng only my second bow an all!!
gave me faith in hickory!
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ps. not saying that my bows now, are of perfect tiller- i think that they are just a bit better!
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Hope it works for ya. Interested in seeing how it finishes up
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I'm very interested!!! More please! :thumbsup: :thumbsup:
Dave.
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This is gonna be neat to watch.
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Very interesting thread. There won't be any fiberglass?
Definitely something I'm interested in as well.
Thanks, LittleBen.
:campfire:
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Looking forward to this. I ask this question if this would work or not, and got few replies. Good luck.
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Looking nice, can't wait to see more.. A tip for you, wrap your limbs with plastic wrap before glue up, that will keep the glue from running down over your form and clamps.
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redhill, no fiberglass ... just wood ... and maybe sinew if the runoffs get too scary.
Roy, I havent wrapped the limbs because I was worried the TBIII would not dry if it didnt get good air circulation. Have you tried this with TBIII? I'd be interested to keep things a bit cleaner .... and Im sure my girlfriend would prefer I dont **** up the porch everytime I have a glue up.
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the other more lengthy alternative , is to varnish the form, and then apply multiple layers of fiberglass release wax
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I never used Tb glue. You could just cover the form and area adjacent to it with plastic wrap, or freezer paper with the waxy side towards the limb. The limbs would lift right off the wax paper.
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Where did you get the 3/16 Hickory and 3/16 Jatoba? Did you order it or cut and plain it. I have built a hickory/Bamboo backed long bow & a few Red Oak long bows. This is just what I was planning for my next project. I will surely be following this.
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James? or Jim?
Anyway, the hickory I ordered as "hickory bow backing strips" most of the suppliers are cutting them 1/8-3/16. The Jatoba ... I found at a sawmill up in NY that was in an area that used to have alot more demand for high end woods, market fell out with the economy. They were sitting on lots of what they called "scraps" of some exotic woods .... jatoba, ipe, cumaru, sanotos mahogany etc. I think I got like 2-3 board feet of Jatoba, 2-3bf of ipe, and like 1bf of cumaru for like $10. The jatoba was already s4s and between 5.5mm (3/16) and maybe 6.5mm (7/32). I ripped it into 1.75" wide strips.
Now I really need to get to building a lam grinder so I can get some core tapers etc.
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It was kind of funny almost, all those "scraps" were either perfect belly lams, or 1.25" x 3/4" x 6ft boards ... perfect board bow wood. Next time I'm up there I really need to go buy like all they're exotics. Down here in DC metro area its a wasteland of mediocre sawmills ... I much prefer the country sawmills ...
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LB.. Thanks for the info...Waiting on your riser design & build.
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Wear a helmet and safety glasses first time you draw her. I'm interested in how the limb wedges turn out.
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Form for the riser being glued up.
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-73.jpg)
Jatoba thinwood (~6mm) for the laminated riser
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-74.jpg)
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-75.jpg)
Maple for the riser
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-76.jpg)
Basic layout for the riser
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/riser.jpg)
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Apex, Why the concern? limb mounting, grain runoff? Just hoping to understand where you perceive the risk to be so I can avoid it ... instead of reliying on my helmet alone. Thanks!
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:wavey:
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Any updates on this build? Sure would like to see it finished, any bow thats just all wood interests me very much,
Robert
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Hey sorry guys, I've gotten a bit off track with this project. Probably wont have it finished for a while but I will certainly post the remainder of the build once I get there. Waiting on some parts from Bingham I just ordered, had to hold off cause the car needed a timing belt, water pump, tenstioner, idler pulley, serpentine, coolant flush, and and iol change. And being as I live in an apartment and can barely find parking, that meant the shop and big$. Anyway thatnsk for the continued interest.
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OK it's been a long time coming but I'm back on this project and making serious progress. Hang in and enjoy!
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-89.jpg)
components ready for to begin
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-94.jpg)
Riser laminated from maple heartwood and Jatoba. You can see the profile outlined on it.
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-90.jpg)
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-91.jpg)
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-92.jpg)
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-93.jpg)
After glue dried, and the profile was laid out, the riser was shaped, mostly, the ends near the limb pads are only roughly shaped, they will be finished once the limbs are attached so it blends nicely.
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Drille holes for the limb attachment. 5/16" hole through the limb for the limb bolt, and 1/4" hole 1/4" deep for alignment pin
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-100.jpg)
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-101.jpg)
Drill the Riser: 27/64" hole for threaded insert - 1 1/4" deep, 1/4" hole 1/4" deep for alignment pin. Tap the 27/64" hole for the threaded insert. Tiny bit of epoxy and screw em in.
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-98.jpg)
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-99.jpg)
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This part is optional and I suspect many of you will opt out, but for those interested:
Install sight/quiver mount inserts: Drill 1/4" hole 3/4" deep, tap and screw in the brass inserts.
Install arrow rest/plunger button threaded insert: Drill 27/64" hole 7/8" deep, drill the remaining thickness of the sight window to 5/16" for the plunger button to extend through (I screwed up and the 27/64" bit snagged the workpiece and busted through so ignore that the hole I drilled is 27/64" all the wasy through the sight window.
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-102.jpg)
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-104.jpg)
Also very very optional, Install stabilizer/wrist sling mount: drill 27/64" Hole 3/4" deep, 7/8 if you want the insert to be perfectly flush, I left mine so it protrudes by ~1/16"
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-103.jpg)
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I just saw this build. I'm interested in this too. Hope it works for you and you don't need the helmet and safety glasses after all!
:campfire:
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That bow's starting to look like a hardware store, has more nuts an bolts on it than I ever seen on a real bow. :laughing: :deadhorse:
But it does look sharp...
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I thought so too Roy. I think it's about 2lbs of wood and another 1lb of hardware. I like the way it's coming out but I'm going to have to build a few selfbiws after this to recover
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Most interesting, I hope it works for you and that the limbs survive the tillering process. Bue--.
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Bolt it together and admire it for a minute!
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-106.jpg)
In this picture, the limbs are still full length, I think they're 26.5" long not including the limb pad area, with a 14" riser, making a 67" bow, tip to tip.
Looking at those recurves, they look like they'll be too unstable and will be a bear to tiller properly, especially with the less than perfect alignment of the limbs.
I went ahead and cut 1.5" off each limb, to bring the bow to 64" tip to tip, and added tip overlays of black phenolic and hickory. Then shaped them a bit. You all know how to cut string grooves so I won't bore you with that.
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-107.jpg)
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Now is a good time to talk about tillering as it applies to wood recurve bows. By no means is this the only way to do it, but here are some of my experiences and advice.
In general the long tillering string lies, so we liek to get to the short string quickly (but still safely and carefully). With recurves, theres an additional problem which is that with the long string, they tend to be very unstable, and I've had more than of flip around and come flying off the tillering tree.
My advice is this, get it floor tillered, pull it s few times with the long string, and just brace it at 1" or w/e. With bow like this that has a pronounced deflex, a low brace puts almost no strain on the limbs. Also, since this is a laminated bow, the limbs are going to be within say 50 thousands thickness before any tillering occurs.
For this reason, amongst others like my laziness, you will not see pics of the long string.
With that said, before we get to tillering, go ahead and cut those string grooves in the tips, and cut some string alignment grooves in the belly like this:
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-109.jpg)
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i can't see any pictures, just a red x in a box
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I don't know why that is. Anyone else having problems seeing the images?
OK, I'm going to keep on moving here, if the images comtinue to be an issue I will go back and make the necessary corrections.
OK few more things before we get to tiller. As I mentioned previously, there is ALOT of grain runout in these hickory backing strips ... maybe 1 per inch. I'm hoping the fact that the limbs are wide and thin (i.e. alot of surface area on the backing to take the load) that it will be strong enough.
To help the hickory out, first sand the backing thoroughly and round over the corners, 80, 150, 220 or 300 grit etc. then burnish the back with a little piece of hickory rubbed against it. This should help to keep down any splinters.
Then go ahead and blend the limbs into the riser as below. This can be donw now or later, or never as you choose.
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-111.jpg)
ignore the fact that some of the riser has finish on it ... I was impatient waiting for th hardware to arrive and tried some out to see the final color.
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can't wait to see more! keep it coming :) !
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Gave it a few pulls with the long string, then once things looked ok, I got it to a low brace height. Here it is at about 3-4"
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-108.jpg)
I was having a little difficulty judging the tiller because I'm much more used to straight limbed bows, or recurves that only hve flipped tips. This bow, as you can see from some earlier photos, has slight reflex along the whole limb, and the curvature increases as you move towards the tips. So to have even work along the limb, the inner limbs will appear to be bent more than the outer limbs.
After much staring and head scratching, I decided that there were weak spots at each of the fades. So for the rest of tillering they will go untouched.
I worked on the mid-outer limb areas of both limbs, as well as weakenging the lower limb slightly to match the upper limb.
Since I started with only ~.350" limb thickness, this will be slow going with very careful wood removal. Wide, thin limbs will lose alot of weight if I accidentally hinge a spot and have to tiller down to remove it.
Alot of you will probably scorn me for this, but I do most of my tillering on a belt sander. Yup that's right. I don't recommend it if you're new to the game. Then I move to using a scraper on the braced bow. Alot of that has to do with the fact that I dont have a workbench on account of being an apartment dweller, all of this needs to be done while holding the bow.
Usually I use a really coarse belt, especially for bows with limb thickness in the .500"+ range such as longbows. But for this I'm using a 120grit belt and very light careful touch.
All the super fine tillering, and final sanding is done by hand obviously.
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Did some more work on the tiller. Got things bending more evenly. Once the tiller looked balanced between the two limbs, and the limbs had no hinges or obvious weak spots, I began reducing the weight slowly, and increasing the draw.
I usually like my bows in the range of 50-60lbs @ 28" (40-50 @ 26") but for this bow my main concern is the runout in the hickory backing. My number one concern is having something to shoot at the end. Plus I have a stash of Jatoba lams (.200") ready to go for some matching R/D longbow limbs which will get better backing strips. So I can always shoot for some more weight from those.
Here we are at 20" (I think) of draw. Still looks liek some slight weakness just after the fade on the right limb. I'll leave that spot alone as I continue tillering, and reducing weight.
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-110.jpg)
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Your sure are pouring a lot of time and effort into a skeptical backing coupled with an over stressed design. Good luck at the finish.
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PD I really had some doubts about it too but if there's no risk there's no reward. Fortunately even though the backing was questionable, and the design highly stressed, I must have been in the favor of the gods because I managed to eek out a bow.
Here it is late in the evening just before I had to end for the day, drawn to 26". No frets, no splinters ... Knock on wood.
Ended up at about 45# @ 26". Had to heat some slight limb twist out of each limb but it was quick work. Just be careful not to overdo the heat or the correction.
Now it's time to put on a few coats of finish on it.
(http://i1212.photobucket.com/albums/cc450/Benjaminklein/photo-112.jpg)
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Might wanna shoot that a good hundred plus times before ya go sealing it up...n right limb is a hair flat mid limb by about ten+ more scrapes
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Good catch thanks! I'll scrape that a bit before I get it finished. I would like to shoot it before finishing. Well see because the range is a good drive from here.
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wow that is cool!!
would a light silk backing add security for the backing lams- or would the extra weight be an issue