Primitive Archer
Main Discussion Area => Bows => Topic started by: arachnid on February 24, 2014, 09:06:25 am
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Hi Guys.
I found a board of Ipe with straight grain and I have some white oak left over
so I decided to go for a white oak backed ipe reflex deflex bow.
The Ipe board is about 61" long and 1 5/8" wide.
I`d love some suggestions about the optimal dimensions (if there are) for that bow please.
I`m shooting for 40-45lb bow.
Thanks in advance.
Dor.
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How long do you intend to draw it?
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Oh sorry... I forgot.. my full draw is 26"
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anyone????
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anything backed ipe is going to be thin, you dont need much ipe to make a bow, Often people suggest 1 1/8" width or less if you dont want much weight, you could probably do a pyramid taper from 1 1/8 inch to 1/2 inch and then the last six inches of tips could taper from whatever width to like 3/8ths or even 1/4.
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Thanks a lot.
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go 1 1/4" with a 14" center section then taper to 1/2" tips
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61" is pretty short, even for a draw length of only 26". Make is bend through the handle and a tad wider than normally with ipé. I like Bubby's suggestion of 1¼" wide. Glue it up wider of course, but the final width should be around 1¼". Don't glue in an excessive amount of reflex/deflex. A little goes a long way. I just finished a BBI R/D with a mild profile (picture to come this week).
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I think somewhere between bubby's and muffin's dimensions will get you close ;) Just keep an eye on your thickness while tillering - if it starts getting too thin, start tillering from the sides. It doesn't take much ipe to make a bow.
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The problem with this board is that after 61" the grain starts to run off.
I can make it a bit lighter (mabye 35-40lb)/ For the handle, thought of gluing several laminations
to make the handle bend a bit.
My plan so far is:
61" total length- 7" bending handle + 2 limbs, 27" each
deflex-reflex design
Pyramid taper, width of 1 5/8" tapering to 3/8" or 1/4"
Limb thickness tapering from 7/16" to 1/4".
Is this any good?
Any suggestions will be most welcome.
P.S
How long should I make the reflexed tips?
Thanks.
Dor.
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For the handle, thought of gluing several laminations to make the handle bend a bit.
What do you mean by this? If the ipé is thick enough, you don't need to add more wood to it. If the ipé is thin, like 7/16" or so, then a powerlam glued between the ipé and the bamboo, will add sufficient thickness to make the handle a bit stiffer. Only if you want a stiff handle (which I don't recommend given the short overall length), you should consider glueing down several laminations. A little bit of additional thickness goes a long way in stiffening up the handle! What thickness is your ipé lam?
A limb thickness tapering to 1/4" is way too thin. You need about 7/16" total (boo included) at the tips. The width can be 1/4" though.
How severe is the grain run off after 61"? You could perhaps make the bow 64" or so, since the last 3" with grain run off are in the stiff tips anyway, so a bit of grain run off won't matter nearly as much. But it's hard to judge without seeing a pic of the grain run off.
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A stiff handle is very doable still for your stats given its the correct design,and more importantly the execution of the design...it all depends on you and what you want...you can do either stiff handled or bendy/semi bendy handle with it...plenty of examples out there showing you what can be done...do some Google searches for ideas...I know David Knight and plenty others nave made some sweet bbi's with the length you have to play with and stiff handles drawing 28"...
Can you post some close up pics of your ipe please,and show the runouts and be specific as to where it is on the board? Like jorik says you might have more length than you think? Which in case if you do I'd def go stiff handle
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I hope you can see it clearly in these pictures:
https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-ash3/t1/p206x206/1380135_581903881899340_727286735_n.jpg
https://fbcdn-sphotos-f-a.akamaihd.net/hphotos-ak-prn1/t1/1620903_581903911899337_1994406329_n.jpg
The first one shows the runout, the arrow points at about 61".
The second one show the rest of the board beyond 61".... looks nasty!
Its the first straight grained Ipe I found, so I really want to do something with it.
DarkSoul- I meant gluing 2-3 laminations, 1/8" thick each and get a semi-bendy handle. Will it stiffen the handle
so much?
And about the limb thickness, you meant 7/16" all over (uniformal thickness)?
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I've made a hickory backed ipe bow a while back. It was 68" tip to tip, 1 3/8" wide tapered down to 1/2" at the pin nocks, and 1/2" thick at the fades tapered to 7/16" at the nocks, and it came in at 30# draw at 28". I hope this helps!
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IF I'm seeing things correctly I'd think you can eek out at least 3 more inches out of it... and in that case I'd def go stiff handle if that's what ya wanted, or bendys still fine...64" is plenty for a 40ish pound bow at 26"...and with that length either stiff handled or not I'd lay it out 1 1/8" wide at the fades and run that length anywhere from 6-10-12" out or to mid limb(pending on quality of wood, n how severe n extreme of a design) and then taper to 1/4" tips...and use tip overlays so you can get your tips that narrow...its crucial you do with woods as dense as ipe...if ya lay out your handle section parallel thickness a half n inch all you'll need is a powerlam(1/8" at its thickest)to make it a slight bendy or bendy handle bow..and that leaves plenty of meat for what ya want...or if you have more than a half inch thickness start a hair thicker thru the handle section...how thick is that board? Can ya rip it into two and get two bows? Lots you can do with this..up to you what ya want?
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Thank you all guys.
Blackhawk-
I think I`ll go on with your dimensions. Just 1 thing I didn`t get- Is there no taper at the thickness?
Is it 1/2" fades to tips?
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if you want a bendy handle and want to add thickness to fill your hand you can use strips of leather glued together and then shape or us cork, I have used both and mostly use the cork and the handle will still bend
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Arachnid, I still would like to know the thickness of the ipé board. It's apparently over 70" in length, 1 5/8" wide and what thickness? You may be able to get two bows out of that board.
There is obvious grain run off, but not terrible enough to render the end useless. I think I'd personally cut the board to 66" for now. After the glue-up, the ends probably need to be trimmed so you'll end up with 65" or so. I'd make it a bendy handle, but that is personal.
One powerlam (about 14" length, very gradual taper from zero to 1/8" thickness in the centre) will really stiffen the handle of the bow. If you would add three or even two lams of 1/8", you will have a stiff handle. So, do you want a stiff handle or a bendy handle?
There will be some thickness taper, but that needs to be determined during tillering. For the glue up, start with about ½" of ipé. Floor tillering probably requires ½" total thickness (bamboo included), tapering to 7/16" (total thickness again, ipé+bamboo). Most tillering will be done in the area from mid limb out to the tips, where the thickness will end up to be lowest. But you shouldn't worry so much about the thickness, since that is determined during tillering and is different for every bow. You just need a figure to get you started with the glue up, and that figure is ½" ipé (and max 1/8" bamboo).
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The board thickness is 3/4". But even if I wanted, I can`t rip it since I don`t have a bandsaw nor a tablesaw (and a jigsaw is not suitable).
I`m not going to back it with bamboo but with white oak, 1/8" thick. I`ll cut it a bit longer (say 64")
and go on from there.
I`ll start in the next few days and keep you all posted.
Thanks a lot guys. It`s so good to have such a supportive community!
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Yes you want to thickness taper all your lams backing included...guess ya only got one bow in there then,unless ya wanted to make a tri or quad lam ;)
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I`ll stick with ipe & oak for now. Its my first run with ipe, I want to
keep it as simple as possible.
Just one thing you guys didn`t mention- how long should I make the reflex? I don`t what something too extream,
just to add some speed and looks.
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If you want it simple just make it a straight bow.
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I meant as simple R/D bow as possible....
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if you don't thin the epe before glueup you wont get a d/r, it's to friggin' stiff, if you want some reflex at that starting thickness glue it up and with the w oak down place a 2x4 block under the center section of the bow and clamp the tips down, that is if you use tubes as clamps, simple reflex with simple tools, Bub
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I`m planning to thin down the ipe, make sure it bends a bit and only then glue up the oak backing
and give it the reflex.
I think I`ll make a build along so guys can see the process.
What Say thee?
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I have been following this thread closely. I have a bunch of Ipe but didn't think of using red oak to back it. Hope your build is a success.
Patrick
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it's a white oak backer, humongous difference between white oak and red oak
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Patrick, Its my first time with ipe and I`ve seen people back it with white oak so I thought- "Hey, why not?"
If we already mentioned the white oak, I have strips, 1/8" thick, sawn from a straight grain board.
It should do as backing, right? I don`t have to use any "special" backing strips, right?
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white oak is a great backer as long as it has straight grain, quartersawn or flatsawn?
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it's a white oak backer, humongous difference between white oak and red oak
Thanks for pointing that out. I meant white oak, but now I know red is not as good as white for backing strips.
Patrick
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white oak is a great backer as long as it has straight grain, quartersawn or flatsawn?
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Can`t remember, I had it for some time now.....
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Well, an interesting thing happend today.
I have a jigsaw table that I built for my Bosch jigsaw and thought I`d use it to thin down the ipe.
When I got to the middle of the board, I noticed it cut it fairly well (for a jig saw) so
I decided to go on and try to rip the board.
Long story short- I ended up with 2 staves of ipe, each one 1/2" thick.
Guess I can make 2 bows after all (just need to find something to back the second one).
I`ll never think the same about jigsaws.....