Primitive Archer
Main Discussion Area => Bows => Topic started by: radius on September 18, 2009, 01:22:41 pm
-
i see that usually, recurves are made short. If i make a static recurve, is my draw length limited to the length of the limb which is NOT included in the recurve? What i mean is, if, after the handle and recurve i am left with say, 23" of available bending limb, should i limit my draw length to 23"?
-
what type of wood you will you be using?
-
white oak...limbs 1.75" wide
-
board or stave? Generally you will have the same amount of working limb with a straight or recurved bow. The recurve allows you to bend the bow farther, adding more strength to the limbs but also stressing the limb more.
One of the osage recurves I built is 60"t/t with a symmetrical layout. I use a 4" handle and 1 1/2" fades. I generally leave the last 5"(average) of each limb stiff also. This gives me 4"(handle)+ 2"(fades[only a portion will remain stiff])10"(tips) = 16" subtracted from 60"(bow length)=44" (working limbs) divide that by 2 = 22" and I tillered out to 28". Adding the recurves really stresses the bow so the tiller has to be right on and the wood has to be able to handle the stresses.
-
thanks Pat
i recurved the 54" piece yesterday, both tips. It's quarter-sawn white oak, so no chasing rings or anything. The tips are about 5/16 thick, but i left them an inch wide, tapered down over 6 inches from 1.75"...
in a week or so i'll get back to it...
do you think the 66" recurve is a reasonable idea? too much? maybe i could get a 75# er out of it???
-
I have never recurved a board bow. With the extra stresses a recurve imparts I think I would back it with something.
66" is fine for a recurve for 28" draw. Much more length than that you loose the recurve advantage because of limb weight and less highly stressed; like with a sinew backed bow. Keep them on the short side to take advantage of the overly stressed limb.
-
will do, none of those 7 foot recurves like in Lord of the Rings...
a 66, a 60, and a 54...that's the current experiment
-
Considering you've just made all those Holmies... you should be able to answer your own Q as it's geometrically similar..
I havn't done the geometry and my maths is pants... but intuitively, one would think the additional limb length would add slightly to the available draw length.
Hmmm maybe I'm going to have to break out the drawing board and compasses before my brain explodes.
You are a very bad man to ask such seemingly innocent but feindishly difficult questions :'(.
Definite maybe I reckon...
Del (the visualisation centre of my brain is frying now...beam me up Scotty)
-
Considering you've just made all those Holmies... you should be able to answer your own Q as it's geometrically similar..
I havn't done the geometry and my maths is pants... but intuitively, one would think the additional limb length would add slightly to the available draw length.
Hmmm maybe I'm going to have to break out the drawing board and compasses before my brain explodes.
You are a very bad man to ask such seemingly innocent but feindishly difficult questions :'(.
Definite maybe I reckon...
Del (the visualisation centre of my brain is frying now...beam me up Scotty)
Del, you from Britain, man? I'm going there in the winter for a bit, and then again next spring. Yorkshire...
Anyway you are right about holmies and recurves being similar. Both flatbows. I learned from the holmies that heat-induced reflex stays in the bow better if it is done when the limbs are thinner...less of the tempered wood is removed...So i did that, for the two shorter bows...the longest-limbed bow, i epoxied a chunk of rosewood on the back of the handle, so i don't wanna apply heat there and lose the bond. Then again, i can try to get as close as possible and use and ice pak on the handle to prevent the wood from overheating. I did that yesterday to protect the glued-on belly overlays, meaning that one of the bows is heat-tempered about 2/3 of the limb, beginning at the fade...
i'll download some pics in a minute
-
some pics...
so i picked up another quarter sawn white oak board...all told, 55 dollars for 6 bows worth of wood...
deciding (from the holmegaard experience) that 1.75" would be plenty to make the bows i want (about 40#'ers), i ripped 3 sections off the board. These i cut to 66, 60, and 54 inches. With the advice i just got from Pat B, i'm going to tiller these out to 28"...yikes! the 54" bow is probably too short...but i'm gonna try! Tim Baker says white oak breaks AFTER hickory, so that's encouraging. Also, i have firsthand experience of how well it can hold up under pressure, even surviving a horizontal little crack across the back. 40# should be okay...
So i cut each one out with the hobby bandsaw, cleaned up and recurved the tips...added some belly underlays (of rosewood...necessary because of some damage the bellies took while bending them)...and heat treated a couple...now i have a few days to let them sit and wait...
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture013.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture015.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture021.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture026.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture028.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture029.jpg)
-
good lord!!! Talk about heat treating the bellies!!!! Looks kinda like the toast I made for breakfast this morning LOL. :) Good idea on the reinforcing of the recurves. Looks cool so far. Wish I had enough time to make 3 bows at a time :'( Keep up the good work. :) -josh
-
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture030.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture031.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture032.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture033.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture034.jpg)
(http://i283.photobucket.com/albums/kk314/NomadArchery/oak%20recurves/Picture036.jpg)
AS you can see, i've turned the longest of these bows into a deflex/recurve...we'll see how that goes.
-
Making 3 bows at a time is an excellent idea. I bet it's much less time consuming then making one at a time also.
(I just wanted to post something to easily find this post later)
-
Del, you from Britain, man? I'm going there in the winter for a bit, and then again next spring. Yorkshire...
Yup, Im in Harlow which is just north of London, long way from Yorkshire (well by UK milages). Yorkshire has some nice scenery. Leeds is up that way, the Royal Armouries are there...some incredible armour to see there and some decent Indian food too.
If you ever go to London, let me know, it'd be fun to meet up.
Del
-
Del, you from Britain, man? I'm going there in the winter for a bit, and then again next spring. Yorkshire...
Yup, Im in Harlow which is just north of London, long way from Yorkshire (well by UK milages). Yorkshire has some nice scenery. Leeds is up that way, the Royal Armouries are there...some incredible armour to see there and some decent Indian food too.
If you ever go to London, let me know, it'd be fun to meet up.
Del
i'm pretty sure york and london are very close by canadian standards!
i will definitely look you up, dude, me and you can go to derby or wherever and check out pip bickerstaffe's bowmaking workshop...
cheerios
-
making 2 or 3 at a time is a good idea and saves down time (if you like to make lots of bows, like i do!)
you can rough them all out at once, with table saw and bandsaw. Then if you heat-temper one, you have others to work on while it acclimatized, etc. Also, the way i've been doing here, you can make them all similar but with some differences, and see what you like the best. For instance, with the holmegaards, i determined that the best general ratio for lever:limb is 1:1, with variations for high poundages or low.
Today or tomorrow i'm picking up a red elm board (i had to special order it, it better be straight like i said, or no buy-ee!) and depending on how wide it is i'll cut it into 3 or 4 staves. Apparently elm is the bomb for recurves, so i'll make one or two elm recurves, and a holmegaard or two, using the 1:1 ratio...
elm is about 5.40 CDN per board foot. that translates to approximately 7 or 8 bucks per stave...hours of fun...cheap cheap cheap