Trad Gang
Main Boards => The Bowyer's Bench => Topic started by: Trenton G. on November 03, 2016, 10:16:00 AM
-
Hi everyone. This is my first attempt at a laminated bow. I used the Bingham 60 inch recurve plan, and was shooting for around 55@28. Unfortunately, it came out WAY over what I wanted, and ended up around 83. I got it down to 75, but I was worried to remove any more material. I couldn't understand what had happened, so I called my buddy who had lent me the form. Turns out he had given me his form for a 58 inch recurve as opposed to a 60 inch recurve. I know that will raise my draw weight, but I don't think that it would cause me to overshoot by 22 pounds. Anyone have any advice that could help me later on?
I built this before I was a member, but I came on here daily and read all of the posts, so a huge thanks to all you guys for the useful information that you've put on here. Without it, I might not have gotten a bow at all!
Anyways, the bow is pretty simple, the riser is just strips of mahogany, sandwiching two pieces of maple with a strip of Brazilian Teak in the middle. The limbs are bocote.
(http://i1174.photobucket.com/albums/r618/trentongiem/bow1_zpsvetievnd.jpg)
(http://i1174.photobucket.com/albums/r618/trentongiem/bow2_zpslomfsh7r.jpg)
-
You did a very nice job on your first bow. The bright side is that you get to build another bow then another and another. Using your data and Stew Miller's stack calculator, you should be able to dial in exactly on the next stack.
Welcome to the gang from the Mississippi Delta.
James
-
I don't know about recurves but on a hybrid 2" will give you about a 5# difference... Nice bow but it looks like its bending a bit much off of the fades... I'm sure others will chime in who know more of recurves... Look at the bright side... at least you are able to draw it... I couldn't... :)
-
Thanks guys. I'm looking forward to building more and learning from my mistakes.
Shredd, I noticed that as well. I'm not sure if that's because of the design that Bingham has, or whether the form I used was not quite right. I don't shoot it a lot since I don't want to destroy my shoulder or anything. I shoot it once or twice a week or 10-12 arrows, then go back to my 60 pounder. Makes it feel light.
-
Great job especially for a first. Much better than the first few I built for sure. Only thing I can add is carefully mike everything before layup and keep a record book. This will allow you much more accurately predict draw weight on future builds.
-
Thanks Jess. When I built this one, I didn't fully understand stack, so I just asked the guy at Bingham to send me what would get me a 55 pound bow. I don't know if he sent laminations that were to thick or what. I will definitely start keeping records from this point on.
-
Looks good Trent. And yes the Bingham 1 pc recurves do bend hard off the fades....
The straight belly on the riser makes it a bit easier to glue up, but I like a more gradual bend there..
-
You may, I say MAY, have miscalculated your stack height for the draw weight you wanted. Having the back and belly glass be .01 too large could make a huge difference in draw weight.
-
You did a fine job!
I have both plans
how wide are your limbs (measure with calipers), and what was the stack, and is yours 58 or 60???????
58 is .264 for 1-3/4 limbs, .254 for 2" 55#
60 is .274 for 1-3/4 limbs, .264 for 2" 55#
The drawings show the limbs being 1-5/8" or 1-7/8" wide for 1-3/4" or 2" glass.
-
22" riser for the 60
21" riser for the 58
-
Very nice.. ^5
-
Thanks guys. I really appreciate all of the help that you guys unknowingly gave while I was working on this bow. I came on here every day to try and learn as much as I could. There's tons of great info here.
Mad Max, I measured the riser and it came out at 22 inches since I used the 60 inch plan. I'll have to get a pair of calipers tomorrow and check the thickness of the limbs. I started with 2 inch wide glass, do I guess my stack should have been .264". I'll do some measurements and let you know.
-
measure how wide the 2" glass is now.
-
I measured them and they are 1 5/8". I narrowed the limbs quite a bit hoping to reduce draw weight, but I was nervous to take off to much so I stopped there. I'll see if I can get a pair of calipers today and measure the thickness of the limbs.
-
You have a nice bow
1-5/8 is narrow enough.
measure the stack 12"from center of bow
-
I won't have access to a set of calipers until Monday. I'll get the measurements then. Also, any idea what happened to my photos?
-
I measured the limb thickness today, and now I'm more confused than before. :confused:
I consistently got between .244 and .242 inches. Even if I did make the bow 2 inches to short, according to the Bingham Draw Weight chart that wouldn't put me anywhere near 75#. Oh well, I guess I'll never know.
I'll see how the next one comes out.
-
next time get someone on here to grind your lam.
I know Big jims bow does them. and there are others.
It's still a nice bow.
-
Ok, I'll do that next time. I've heard of pieces of glass that are the same thickness having different spines, but I don't think that would cause such a big difference in weight would it?
-
If you measured stack 12" from center, you will have .024 more at lam butts. That's where Binghams measures. That and making it 2" short will add a lot of weight.
-
Ok, thanks guys. I think I'll just keep this one for practice every now and then. I can't shoot that weight accurate enough to hunt with anyways.
-
Originally posted by JamesV:
You did a very nice job on your first bow. The bright side is that you get to build another bow then another and another. Using your data and Stew Miller's stack calculator, you should be able to dial in exactly on the next stack.
Welcome to the gang from the Mississippi Delta.
James
I know of the spine calculator, but what stack calculator? I can't find anything relative when googling it.