Primitive Archer
Main Discussion Area => English Warbow => Topic started by: orangputihkgu on June 30, 2013, 10:42:22 pm
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Hello to you all! :)
I have seen lots of Tri Lams. Why are there so little Quad Lams? ???
According to EWBS description a non-historical bow may have up to 4 laminations but somehow this kind of bow is rather a rare species. I can only recall a pictutre of a 4 Laminate made by a member of the EWBS-NZ.
So why are there no more of this kind of warbow? To difficult to make? No real advantage having a fourth lamination? Any difference in performance compared to the Tri Lam?
Did anybody has hands on experience in shooting a Quad?
Any input and information appreciated!!! : :)
-cheers.......CHRIS
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Aside from looks, what would be the benefit of an additional lam?
The back is tension, Belly is compression. The core is shear strength and stiffness.
Making the core 2 lams increases the likelyhood of a delam b/c the glue line is under extreme stress(it is right where the wood wants to shear)
Just my 2 cents, from a person who has never made a laminated bow...
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Maybe us bowyers are just lazy
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Aside from looks, what would be the benefit of an additional lam?
The back is tension, Belly is compression. The core is shear strength and stiffness.
Making the core 2 lams increases the likelyhood of a delam b/c the glue line is under extreme stress(it is right where the wood wants to shear)
Just my 2 cents, from a person who has never made a laminated bow...
+1
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Making a quad lam would be no harder than a tri lam. Just slightly more labour intensive. You'd have to make sure your lams weren't too thick, especially the core lams. I often make tri lams, because I can make more bows with less wood. I need less precious belly wood to make a bow. They also look very nice with contrasting woods.
Proper glue lines are not weak. If done correctly, they're stronger than the surrounding wood. I've never had a glue line failure on any bow, including heavy warbows. The wood itself always fails first. You'd also have to watch that your limb's physical weight didn't get too high using dense core layers. I don't believe there is any advantage to making a quad lam over a tri lam.
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I don't see any advantage to having additional lams. Howard Hill bows are routinely made with 4 lambs and sometimes up to 6, however.
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It is pretty much just for looks the way most people make them. However adding extra lams under perry reflex may have some benefits but you have to do 3 glue-ups.
Why on earth would a 4 lam bow by more likely to fail at a glueline??? If you prepare shoddy surfaces and then expect the glue to hold it all together fair enough but if they are well prepared and you follow the way the glue should be used - no problem.
I quite often make quad and more lam longbows. It just starts getting tricky to 'fit them all in'. The best way to do multiple core lams is to taper them all......which can be a pain but does look pretty special!
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I have been making some reflex deflex bows lately with a good about of bend in the glue ups. I notice when comparing a glue of just a backing to a belly, it will not hold it's reflex too much right out of the form. I mean as soon as I take the bow out of the from the limbs come down a bit loose some reflex. When doing basically the same bow but with 2 belly lams instead of one, it holds it's reflex a lot better right out of the form, and doesn't seem to loose any at all. So might these observations of mine be indicative of added stability/stiffness?
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No it's just that it takes less force to bend thin lams to the shape of a form than it does a thicker belly lam and a backing. Equal and opposite reaction and all that.
If you don't thin your belly lam when doing a perry reflex glue-up as you remove bellywood the reflex increases....now that's a fun situation.
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It sure does. Mike, you are one of the few I've heard recognize the 'reflex gaining' phenomenon. It can be quite the adventure. The more wood you remove, the more reflex it gains, making the limb appear 'stronger' than the other on the tree, so you scrape off even more.... etc. It hasn't happened to me since I began carefully pretapering my pieces and got a bettet feel for how much material I needed to be closer to final thickness after glue-up.
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Many years ago I had a bunch of yew that was already cut into thin 1/16" sheets for glass bow laminations. So.... I decided to make a bow with a ridiculous amount of laminations just to see what would happen. It has 8 laminations of yew, (not including the handle riser). Then a back and belly lamination of the evil glass stuff. At an overall length of 68", 66"NTN, it pulls 110# @ 30". She's a real sweet shooter and flings an arrow like a rocket down range. I still have her.
G
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I'm sure it's an awesome bow, but once you add FG to the lams, everything goes out the window. The core lams (regardless of how many) just become a platform for the FG. The tiller and draw weight are only determined by limb profile and thickness.
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I'm sure it's an awesome bow, but once you add FG to the lams, everything goes out the window. The core lams (regardless of how many) just become a platform for the FG. The tiller and draw weight are only determined by limb profile and thickness.
I have to agree, once you add the glass, the rest is for " looks". You could get by with one or two Lam's for a functional glass bow.
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You just end up with the possibility of more glue line failures. More wood to glue. My first bow was 5 lams, because I thought it would be better. Wrong, a tri lam would of been sufficient. The other reson was I had a dozen or so lams cut at a very thin margin. The next bow I'll try a mild R/D having 2 lams. Either 2 maple or Oak & Maple. Backed or unbacked....
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When you glue up lots of laminations would the glue start to add excess mass?
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I don't think so. The amount of glue left in the glue joint would be negligible. With TB3, the bonding action takes place at the molecular level. A good glue line shouldn't be a line at all... it should just look like the two (or three) pieces of wood are touching each other.
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here is the reasoning I followed-
if you have a glue line, with a 2% likelyhoood of failure... and you add another to make a trilam... you double the possibility- 4%. If you add another- 6%... I don't think I have ever seen a properly prepared glue-line fail on here though...
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The surrounding wood will fail before a properly made glue line.
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here is the reasoning I followed-
if you have a glue line, with a 2% likelyhoood of failure... and you add another to make a trilam... you double the possibility- 4%. If you add another- 6%... I don't think I have ever seen a properly prepared glue-line fail on here though...
I agree 100% ~~~~~ a properly prepared glue-line should never fail, but sometimes haste makes for mistakes that's what happended on my last build. I glued up a tri lam, totally sloppy glue job, sure as crap it broke in the most likely spot......A Big Glue Gap...!
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Lesson learnt. Never rush preparing laminations! Rehearse your glue-up without the glue if you aren't confident.
Squirrel - have you done any study on probabilities? Are you sure you end up with a 6% chance of gluelines failing.....
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mikekeswick- All I am trying to say is that the more glue-lines, the more chances for you to make a mistake.
i doubt its 6 percent for a quad lam bow....
And yes, i have done some in both geometry, alg 1, and we are starting with it in trig.
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mikekeswick- All I am trying to say is that the more glue-lines, the more chances for you to make a mistake.
i doubt its 6 percent for a quad lam bow....
And yes, i have done some in both geometry, alg 1, and we are starting with it in trig.
I couldn't disagree more. Unless your glue lines are very poor, there is absolutely no reason to think the bow is more likely to fail.
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Do something once.Chances are you will get it right.
do something 100 times. chances are you will screw one or 2 or maybe many more up.
this is my reasoning- even though a properly prepared glueline almost never fails.
Those of you who have made laminated bows- have you ever had a glueline fail? How many have you made?
Lets stop this bickering(come on, we are acting like high school girls) and just agree to disagree.
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As mentioned in a previous post, I've made bows in the hundreds... mostly laminated, and I have NOT had one glue line failure. I've broken bows on the tiller plenty, but not one has broken as a result of a glue line failure.
Sorry, I don't agree with you. Practical experience tells me otherwise. Disagreeing is not bickering... it's just an opinion that differs from yours. I do try and base my opinions on experience.
Do something once, it might be good... do something 100 times and it'll likely be better.
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As mentioned in a previous post, I've made bows in the hundreds... mostly laminated, and I have NOT had one glue line failure. I've broken bows on the tiller plenty, but not one has broken as a result of a glue line failure.
Sorry, I don't agree with you. Practical experience tells me otherwise. Disagreeing is not bickering... it's just an opinion that differs from yours. I do try and base my opinions on experience.
Do something once, it might be good... do something 100 times and it'll likely be better.
sounds good.
just every time I try to glue up more than 2 layers for anything i botch the glue-up.
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Quad lam - 4 laminations - Why not more?
here is a bow that was made by the guy who taught me a bit about bow making. not sure on the order but it has 5 Laminate tapered longbow made with Bamboo purple heart Pau Marello and Lemon wood.
(http://i1316.photobucket.com/albums/t614/bowslayerjez/5laminations1_zpsf76bd127.png) (http://s1316.photobucket.com/user/bowslayerjez/media/5laminations1_zpsf76bd127.png.html)
(http://i1316.photobucket.com/albums/t614/bowslayerjez/5laminations2_zpsee7912fe.png) (http://s1316.photobucket.com/user/bowslayerjez/media/5laminations2_zpsee7912fe.png.html)
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As mentioned in a previous post, I've made bows in the hundreds... mostly laminated, and I have NOT had one glue line failure. I've broken bows on the tiller plenty, but not one has broken as a result of a glue line failure.
Sorry, I don't agree with you. Practical experience tells me otherwise. Disagreeing is not bickering... it's just an opinion that differs from yours. I do try and base my opinions on experience.
Do something once, it might be good... do something 100 times and it'll likely be better.
sounds good.
just every time I try to glue up more than 2 layers for anything i botch the glue-up.
Why? How can I help?
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i dunno. i have managed to make a 2-layer(RO and 'boo or cane, really dunno which cause 'cane is a species of boo)...
it delammed cause I left it outside on the woodpile in the sun and rain(glued with tb1)...
I have tried to pull off a trilam. it didn't work. then i tried to do a 2 layer tip overlay on a bow for a friend. it also failed(in a rather spectacular manner)...
i think its just me. I shall stick to selfbows and not have a problem.
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If you can do a bi-laminate, you can do a tri-lam! The gluing process is no different. If you're using TB glues, your surfaces must be clean, flat and fit exactly. Eliminate 'gap filling' from your vocabulary! I use 2" wide lams, and stack them in whatever combo I'm wanting. Wrap with bicycle inner tubes, and you're good to go. The backing and core lams are usually 1/4" thick, and the belly is whatever thickness is needed to make weight.
Stop leaving laminated bows in direct sunlight!! >:( That's not the bow's fault, that's your fault!! If you treat your bows like firewood, that's exactly what they'll become. :o
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yep- the overlay was kept in the basement.
The trilam was my 2nd bow.
and i treat my red oak longbow like firewood with no issues... it seems to like it ;)
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I think above four is ridiculous. The wood would make the limb very heavy and think about this.... Glue is 2x the weight of wood. So if you have a lams worth of glue in the bow it will be slower. Just my 2 cents
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If you can do a bi-laminate, you can do a tri-lam! The gluing process is no different. If you're using TB glues, your surfaces must be clean, flat and fit exactly. Eliminate 'gap filling' from your vocabulary! I use 2" wide lams, and stack them in whatever combo I'm wanting. Wrap with bicycle inner tubes, and you're good to go. The backing and core lams are usually 1/4" thick, and the belly is whatever thickness is needed to make weight.
Stop leaving laminated bows in direct sunlight!! >:( That's not the bow's fault, that's your fault!! If you treat your bows like firewood, that's exactly what they'll become. :o
got a question about trilams-
do i glue it all at once? Cause that is what I did!
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Yes. Definitely. Smooth the glue on all binding surfaces and bind 3 layers with wrapped inner tubes. Same as a backed bow, only you're adding an extra lam.
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Here's a video I made a while back showing how I do it. The video production is not the greatest, but you can get the idea of how it's done.
https://www.youtube.com/watch?v=0a3nhYpq6cY
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Thanks, Cam!
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Here's a video I made a while back showing how I do it. The video production is not the greatest, but you can get the idea of how it's done.
https://www.youtube.com/watch?v=0a3nhYpq6cY
Saw this post referred to in the Tri-Lam thread and so I watched Cameroo's YouTube video on glueing up. My wife wanted me to complement you on your selection of background music. She said, and I quote "...it doesn't get Eddie Vedder than that!" ::) ;D :D (...she claims to be his biggest fan!)
Onebow
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In my opinion, the nature wood fibers especial yew have the least energy loss or heat loss. that's because the natural selection. the more lams, the more glue is included in the bow, which as a buffer raises the heat loss. some body may argues that why most tri or quad lams bow has the higher speed than self bow. 1.Not each wood fibers could be excellent as yew. 2.using denser belly wood and powerer backed lam such as bamboo can reduce mass. 3.more important point is that the lams give the reflex, which stores much more energy than a straight self bow. that's why in a warbow flight competition the straight lams bows didn't show too much advantage than self bows and why a recurve horn bow has higher speed than a self yew bow, but supposing the poundage is up to 150 or more, the higher heat loss would be a significant negative factor.