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Main Boards => The Bowyer's Bench => Topic started by: Martin Schutte on March 20, 2015, 11:58:00 AM
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Hi guys
I`m new to bow making and is a hobby knife maker from South Africa. Thanks for all the info and great bunch of guys on this forum.
I am trying to make a tri-lam of some sorts hopefully Bamboo back(see pic),ash core and white oak belly(see pic)
Now to some needed info, as the subject stated I received some 2.4m long (6.5cm like in the picture) bamboo(moso,muso).
(http://i1380.photobucket.com/albums/ah181/Martinschutte1/Martin%20bamboo/Bamboo1%206and%20half%20cm_zps0u74xv36.jpg)
(http://i1380.photobucket.com/albums/ah181/Martinschutte1/Martin%20bamboo/Bamboo2_zps6mrslg4e.jpg)
(http://i1380.photobucket.com/albums/ah181/Martinschutte1/Martin%20bamboo/White%20oak_zps913ziv6n.jpg)
1st Question: I need to split this boo but not sure where to begin??
2nd Question: If I get it split, can i flatten it some with "steam" so that it can be a wider backing for my bow??
3rd Question: if I go with a 70 inches knock to knock 31 inch draw(scary long monkey arms) bow for a 45-50 pound preferably 50 with some reflex.
What must I make my dimensions for this length of bow the width and thickness and must I taper the core wood!?!?!?
4th Question: Is it necessary for a powerlam??? And can I use some of the wood mentioned for the power lam and what must my handle dimensions be with this beast??
Well I hope I covered everything, sorry for all the rambling but I want to get this spot on so that I can start to feed :banghead: this bug that got me under so much tension and vertigo!!
Thanks again Martin
this is me all fancy shmancy before my wedding last year
(http://i1380.photobucket.com/albums/ah181/Martinschutte1/Martin/1256_zpsxsfkint3.jpg)
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Split the boo into at lease quarters. I large butcher knife will work.
You'll want to reduce the backing by grinding(sanding)flat. That will tell you what width to make your bow. Probably 1 3/8" to 1 1/2" wide. Its not necessary to taper the cores but you can.
The power lam only keep the handle area stiff and almost any wood can be used for that. I've never used a power lam so someone else will have to help with that.
When I make handles I make it 4" with 1 1/2" to 2" fades.
No suggestions for that mug of yours though. :D
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Thanks Pat that is some solid advice, I do appreciate it. So then I can actually glue up the whole Shibang, form the handle apart and glue the handle in later on, like in Roy`s build along!!! Hmmmmmmm seems easy enough NOT!! Thanks again
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Hey Martin,
Welcome.... It's great to see more and more South Africans here. Where are you based?
Have a look at poorfolkbows for a number of really good build alongs.
Thanks
Pete
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Is the bamboo 6.5 cm or 6.5 inches in diameter?
6.5 cm might be too small to work with. Anyway, like Pat said, a large knife will split it nicely. Once it's split into sections, it will need to be flattened. I use a jointer, but a belt sander will work. Once it's flattened on the inside, I cut it to width (1 3/8 to 1 1/2") as well as to the bow's dimensions, then I will plane it to final thickness. About 1/8" in the middle tapering to about 1/16" at the tips.
I'm not sure how thick your core and belly lams should be. I build my bows with a wood or bamboo core and a bamboo belly lam. For my last bow built this way, I used a 3/8" cherry core that tapered to about 3/16" at the tips and a bamboo belly lam with the same dimensions as the back. I also toasted the belly lam with a torch. You can't glue the riser to the belly like this because of the bamboo, so I cut the belly lam in half and glue it to the belly side of the fades.
This bow came out at 57# at 28".
(http://i1177.photobucket.com/albums/x349/1wood1/IMG_0578_zps5cc4e625.jpg) (http://s1177.photobucket.com/user/1wood1/media/IMG_0578_zps5cc4e625.jpg.html)
(http://i1177.photobucket.com/albums/x349/1wood1/IMG_0577_zps325d84d1.jpg) (http://s1177.photobucket.com/user/1wood1/media/IMG_0577_zps325d84d1.jpg.html)
I hope this helps.
Dave.
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Sorry, the bow in the pictures is not the one I described. I don't have a picture of that one.
Dave.
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Hi Pete I`m from Pretoria and will have a look at those build alongs!! Waar is vandaan?
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Hi Dave
6.5cm that is the largest bamboo I can get this side and import is out out the question with our currency as crap as it is and our post office system always busy busy with a slow go or on "industrial aerobics"(striking).
So for now I must deal with 6.5cm (2 9/16inch) or can i steam the bamboo and flatten it that I have a wider piece to work with??
Thanks Martin
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6.5" yes, 6.5cm maybe but probably no.
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That piece of boo will be very close. You can get away with 1.5 inches wide after it's flattened on the inside walls. Maybe just split that in half, then cut it down with a band saw and see how wide it ends up.
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If it was 6.5 inches, I'd be extremely jealous of you. :) One thing I discovered is that bamboo will cup outward when it's heated. This will help you get it a little flatter. Plane it flat, then heat it, then plane it again to finish flattening it. I don't know about steaming it, but it would be worth a try. What do you have to lose? Let us know if steaming works.
Good luck with your build.
Dave.
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looks a little small in diameter.
I know you can straighten bamboo arrows with dry heat.
I wonder if you can flatten the curve with dry heat and pressing it flat progressively down the length?
That's sorta bending things the opposite way..maybe it'll work?..maybe it'll split.
...maybe even if ya do flatten it the boo won't be good for a backing anymore..
...what do I know?...nothing really..I do know that. :knothead:
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Hi Guys
I went and split it in half(not very well I must add) and then split one of them again, ground it flat it is now 1.18" 3cm at widest part. The nodes makes it look wider(some stick out on the side) but must flatten it I think?! So maybe I can get a medium descent bow with this backing, let the chaos and head scratching begin, one observation i have never worked with bamboo but this piece of bamboo got more flexible while thinning it thats my conclusion
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Dave maybe I will try steaming it and them flatten it as a test to see what I can expect, or try the "heat cup" method you suggested!
Martin
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Thanks Roy for chiming in so got it to 3cm/1.18" so now I must figure out what to build hmmmmmm??? Maybe I can pull something out of the magic hat!
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Also got to measure the bamboo thickness after i ground it,its 5mm or 5/32 of an inch I hope my convertion is correct from mm to inches! Imperial confuse the hell out of me!
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1.18 is narrow, but some type of bow is possible. Maybe not a higher poundage bow but certainly 40 at least. You could make the belly lam wider and taper the sides of it in towards the boo backing on the back, while leaving the edges wider and rounded off..
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I had a failed attempt last year because I didn't taper my core and the bamboo enough. It would've worked if I went from 1/8 from the center of the handle to 1/16 at the tips. Just wouldn't want you to have the same problem I had. I over powered my belly lam. I think the thickness was around 1/8 to 3/16 on my back and core lam(not tapered at all). Tillered til it blew and the belly was paper thin at that point.
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Hi Guys
Now that its weekend, and the hectic week is over I can focus on this build of mine. I took some time and drawn a "rudimentary" :D pic of how my small mind thinks on how thick my lams must be the bamboo is already at 5/32" and I don't think its necessary to taper in thickness??? The White ash(Actually picked up some yesterday with some very purdy massaranduba for my next project/s) I must taper from the centre(1/8") to tips(1/16").(Taper measurements from Kevinnator11 thanks)
So now the white oak is round about 3/4" thick after purchase and can thin it down if need be what thickness do you guys think I can use!!
So Mr. Incredible (Roy) on the belly lam i`ve drawn a rendition what I understood on your comment taper towards the bamboo(bottom part of pic) did I capture it correctly??
Thanks for all your patience sorry for me being a bit slow :bigsmyl: !! I`m a kinda monkey see monkey do person until it clicks and I see the bigger picture!!
(http://i1380.photobucket.com/albums/ah181/Martinschutte1/Mobile%20Uploads/IMG_20150328_085236_zps42jxqqlm.jpg?t=1427440010)
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Yes Martin, that should be fine.. But I would round over the belly lam edge a little more so as not to have a crisp edge on the belly of the bow. But leave the sides exactly like your picture shows.
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Thanks Roy I see what you are trying to tell me and will round the sides more to make it almost look like a oval/egg :knothead: . Thanks for the pm!!
On the belly lam is 3/4" too thick??? or Must i thin it to get a bit of bend in the glue up!!??
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3/4" is fine if you want a 100 pound bow.. LOL
Oval/egg shape is perfect..
I would make the belly lam and core lam both 1/4" thick. Leave the belly lam parallel, taper the core lam from 1/4" thick at the riser ends to about 1/8th thick at the tips.
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I think Roy's suggested dimensions are right on. Looking forward to seeing this turn out
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Hi guys I got the wood planed at a friend it ended up 7/32" not 1/4" as planned but it will have to do! I also decided to plane the massaranduba while having the opportunity. Note to self a very important note use a respirator for this wood. I wanted to die, this stuff gave me and my buddy a violent asma type attact, it burns you're throat and nasal cavity like pepper spray/mace :scared: ! So soon a bow on the way!!! :bigsmyl:
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Big 10-4 on the respirator.... And gloves and eye protection..
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Thanks Roy will take that under serious consideration but the bow is on the way! Hopefully after fixing the brakes on my car tomorrow I will be starting slowly to taper the core lam!
Thanks for all the encouragement will keep you appraised of my slow progress :) I am officially slower than you!
Martin
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Hallo Martin,
Goed om nog Suid Afrikaners hier te sien! Jy kan ook vir Derek Nourse in Natal probeer kontak as jy raad soek. Hy het self al heelwat bamboo backed boe gemaak. http://norsemenarchery.co.za/historical-bows/bamboo-backed-osage-longbow/
Groete
Johan
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Dag sê Johan dankie vir die raad!
A quick update my free hand attempt on grinding the tapers on the core lamination ain't gonna work so need to mod my grinder, I spend my morning surfing the interweb and after some head scratching came upon the "jig" that will make my headache of free hand grinding dissolve into a massive grin! I will put the results into this post.
Martin