Primitive Archer
Main Discussion Area => Bows => Topic started by: paleryder on February 19, 2013, 01:15:42 am
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Okay, not really but each one feels like the first one. I'm actually referring to "Your First Wooden Bow" in the TBB4. I'm building the bendy bow. I haven't built one in a while so I wanted to start out with a solid plan. Bow is to be a gift. Shooting for 50lbs. Okay...
I get it down to dimensions and weigh it. It's 19.2oz. I was referencing the mass principle chart and it is suggested that the target mass for a 50lb bendy bow is 14.5oz for a 70" bow at 28" draw. It's not a primitive word but have I "hosed" myself here? I have less than 5oz and I haven't even tillered the bow yet! I may have gotten too aggressive on thinness taper. Not sure what I've done. I rounded off the back of the handle as instructed. Maybe I took too much off.
Has anyone else built this bow out of red oak? Do I have anything to worry about or am I just being a nervous nancy?
Todd
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How about some photos and/or measurements? You may be able to thin the limbs out towards the tips toi remove mass without changing tiller much.
And my favorite line from the movie, Pale Rider, "I do like a good piece of hickory."
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Great line!
Here we go:
70" ntn
middle two feet: 1 1/2" wide. Tapers to 1 3/16 inches wide at mid limb. 1/2" wide nock.
Handle section 5"long and 3/4" thick. Book said to round the back corners off the belly side to allow the arrow to set against the bow. Did this so it is not rectangular in the handle on the belly side. May have overdone it.
Each limb then fades from 3/4" down to 5/8" about 2" out from the handle then to 9/16" thick at mid limb. It's then about 9/16" thick to the tips (about another 17.5"). Actually one limb is combing in at 9/16 towards the tip while the other is at a solid 1/2" thickness. Looks like I came in a little under each measurement, like a 1/64 or something. I hope the beginning dimensions are so senstive that 1/64 will blow it.
I'm really feeling the handle bend when I floor tiller. Yikes. My fear is that 5 oz is too little and I'm going to have to remove a lot more than that to get the bow tillered and I'll come in significantly under 50lbs. I haven't paid attention to mass before so I don't know how much 5oz is once you start tillering. Is that a lot or a little?
Thanks guys.
Todd
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Eh, I blew it. 35lbs. It wasn't because of only having 5oz to go after roughing out- not by a long shot. Three problems:
1) haven't made a bow in a couple of years and I'm really rusty.
2) first time using a tillering tree (pulley set-up) instead of an old stick. The damage was done by the time I braced it. Not being familiar with the feel of the tillering tree w/pulley, I overestimated how much weight it was taking and had reduced it too much. My goof.
3) I was shooting for a target mass of 14.25oz for a 50lbs. I left waaaaaay too much on the tips and the mass dropped to 16.1 oz and I'm done- well, overdone really! I was deceived. I should have reduced the limb tips earlier I suppose. They're about 1/2 x 1/2 at this point.
So, bow is 69" n-t-n, just under 1 1/2 wide for middle two feet, bend in the handle (somewhat rigid handle) bow. Weight 16.1 oz. So, it would seem that for a 35lbs bow, I'm seriously overweight as far as mass is concerned. What can I do?
A. keep it at 35lbs and live with it. Make a new bow.
B. monkey with the ends to reduce mass to improve performance
C. pike it and/or heat treat it to get to my original target of 50lbs. I know I've been warned about heat treating red oak. Not sure how much increase in weight I can get shortening it.
It has only 1/2" string follow on each limb and one of the limbs started with 1/2 string follow. I feel pretty bad at the moment. This was to be a gift for a friend. Hope someone has a miracle cure.
May it be blessed,
Todd
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I like B and C. I think I would pike it down to a 66" overall length and maybe flip the tips a little. I have never toasted red oak, but I know that white oak loves it. Good luck with it.
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I'm a little late with a reply, but I would agree with taking an inch or 2 off each end and heating it. I also have not used red oak, but it works great on white oak, elm, osage, mulberry, maple.
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Thank you, both. I'm definitely going to cut it down. I'm going to have to ponder the heat treating.
Todd
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If you got 70" of bow, you can take off plentyof limb length and still turn in a 28" draw length. You maya even be able to go as low as 62-64". You may bet a bit more set in the limbs, but that's life in the big city. Trim an inch off each limb, check tiller, minor adjustments as necessary, repeat as necessary.
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Well, I finished the bow. Sort of. I have it strung and shooting and do not anticipate any more tillering. Pretty much all I need to do is some finishing and I'm done. My target was a 50lb bow. Here's what I got.
Overall lenght: 66"
NTN length: 64"
Mass: 15.57oz
Draw Weight: originally weighed in at 46# but after shooting about 100 arrows, it weighed in about 44#.
String follow: Just after shooting, the limbs were at about 1 5/8" and settled in about 1/2 hour later to 1 1/4"
I started with Tim Baker's "First Wooden Bow" and had a 70" length. Since it came in at 35lbs, I cut it down twice to the current length. I didn't change the dimensions as I cut it down and mostly cut down thick limb tips. I ended up with this
Top limb: Tip 41/64w x 15/32t; mid limb (from handle to nock) 1 1/4" w x 29/64" t
Handle: 1 1/2" w x 3/4" t
Bottom limb: Tip 19/32 w x 31/32t; mid limb (from handle to nock) 1 17/64w x 15/32t
Here are some pics
Profile:
(http://i1039.photobucket.com/albums/a480/paleryder1/P1010283_zps3565dabd.jpg)
top limb side
(http://i1039.photobucket.com/albums/a480/paleryder1/Archery/Kevins%20bow/P1010284_zps6684f7b4.jpg)
top limb front
(http://i1039.photobucket.com/albums/a480/paleryder1/Archery/Kevins%20bow/P1010286_zpse7fc4f17.jpg)
bottom limb side
(http://i1039.photobucket.com/albums/a480/paleryder1/Archery/Kevins%20bow/P1010285_zps8a1431ce.jpg)
bottom limb front
(http://i1039.photobucket.com/albums/a480/paleryder1/Archery/Kevins%20bow/P1010287_zps202f8938.jpg)
I shot about 75 arrows at less than full draw length to break it in. I then took it out shooting just after weighing it in at 46# @28" using a string weighing 211gn (had a tail from when the bow was longer) and here's what happened.
Weight 1 2 3
1. 475gn 180 153 183
2. 481gn 152 155 157
3. 481gn 154 153 154
4. 481gn 153 153 152
5. 481gn 153 184 153
6. 489gn* 151 149 146
7. 492gn* 151 151 154
8. 481gn 150 153 155
*different make w/ larger fletchings
From what I can tell, it's performing well. I'd like to tweek it, if possible and if not too much trouble. I don't want to have to retiller and lose any draw weight. Like I said, I didn't adjust the limbs much after I cut them down twice. I did very little tillering. Maybe I should have! :-)
What can I do to boost my arrow speed without compromising the bow? I figure I'll lose a little weight sanding but I try to clean up the bow as I get close to final tillering so I don't have a big change.
Will narrowing the tips more make any real difference at this point? Will they require an overlay?
Thanks a lot for your help. You're all an invaluable resource.
May it be blessed,
Todd
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You might get a little improvement by narrowing your tips, or heat treating, but doggone it, you got a pretty respectable bow there, as is. I think I would just shoot it and call it finished. Picking up ten lbs of weight is a pretty good tweek already. ;)
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I can't figure out where all the mass is. If I were to reference TBB 4's table, it suggests a bend in the handle bow at 66" might weigh 12.5oz and a 64" might weight 12oz. (not sure if the chart is total length or n-t-n). I don't think there is 3.5oz in the limb tips. My guess it is in the handle somewhere. I'm not going to mess with that but if anyone can tell by the profile at full draw where that mass is hiding, I'd appreciate it. It might help next time.
I might narrow the limbs just so I can church it up a bit with a horn overlays on the tips. My bow is a gift to a long time friend and I'm going to decorate it up nicely...I hope.
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You might be able to narrow the last 4 or 6 inches a little. I am a believer in heat tempering. At this stage it might be the only way to bring the draw weight up, other than marming. Heat tempering is a lot simpler though. If you do heat it, make sure the heat doesn't get to the back and it will permanently darken the belly.
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I'm going to take Howard's suggestion and stop while I'm ahead and still have a bow. I thought about heat treating it but I think I'll leave it alone since it's actually shooting. I'll try heat treating the next time around.
Thanks for the advice.
Todd
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Well, here are the finished picks. Sorry about the quality. My camera's dead and I used my cell phone, which does not take consistent pictures.
(http://i1039.photobucket.com/albums/a480/paleryder1/Archery/Kevins%20bow/IMG00285_zps48e89def.jpg)
(http://i1039.photobucket.com/albums/a480/paleryder1/Archery/Kevins%20bow/IMG00286_zps0e3346e9.jpg)
(http://i1039.photobucket.com/albums/a480/paleryder1/Archery/Kevins%20bow/IMG00290_zps06c4e149.jpg)
Ever notice that wood has...grain? I must have forgot. I tried to write on it with a quill instead of using a brush. :-[ I used India ink to do all the decorations. Not sure yet how durable it will be. It dries very quickly but is difficult to fix mistakes. You can't see it in the picture but I goofed pretty badly on the bow name and it smeared. Couldn't quite get it all cleaned up.
(http://i1039.photobucket.com/albums/a480/paleryder1/Archery/Kevins%20bow/IMG00288_zpsd76613a0.jpg)
I had part of a nock start to split off one of the side edges. I used artificial sinew and some epoxy to fix it.
(http://i1039.photobucket.com/albums/a480/paleryder1/Archery/Kevins%20bow/IMG00289_zps21a86190.jpg)
Here's I'm drawing it with the bottom on top. Trying to figure out which limb should be on top.
(http://i1039.photobucket.com/albums/a480/paleryder1/Archery/Kevins%20bow/IMG00292_zps096fae51.jpg)
I'm still uncertain if I'm out of danger. Need to shoot it more.
Enjoy. Thanks for all your help.
Todd
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Tiller looks good but dont take my word for it. :laugh:
The reason for your nock problem I think is string angle. Try and make them 45deg plus, also best to leave the back of the bow along when making the nock grooves. Adding an overlay and re-shaping the nocks is east to do.
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Dwardo,
Thanks. So, I can just file the nock at a little sharper angle then and that shoudl fix the problem?
How do you cut the nock and not cut into the back?
Are suggesting I should do an overlay here? It sharted to peel off a corner on the back side. I'll round that off because it was at a sharp angle.
Thanks again for your input. Always helps.
Todd