man this really looks crazy to me at nearly full draw. tiller gizmos says ok but am i too stiff on the outer thirds? never tillered an asymmetrical bow before, so its just throwing me off and i need second opinions. im at 42#@28". Limbs are synced.
(http://i1308.photobucket.com/albums/s608/echatham/IMG_20130828_160113_161_zpsea1c466e.jpg) (http://s1308.photobucket.com/user/echatham/media/IMG_20130828_160113_161_zpsea1c466e.jpg.html)
(http://i1308.photobucket.com/albums/s608/echatham/IMG_20130828_160101_321_zps2f4f8c36.jpg) (http://s1308.photobucket.com/user/echatham/media/IMG_20130828_160101_321_zps2f4f8c36.jpg.html)
(http://i1308.photobucket.com/albums/s608/echatham/IMG_20130828_160248_064_zpse3e2f7f7.jpg) (http://s1308.photobucket.com/user/echatham/media/IMG_20130828_160248_064_zpse3e2f7f7.jpg.html)
Looks good to me. I'm sure many people with much more experience will chime in, but it looks like the outer thirds are working the correct amount (just a bit). Those tips are sweet! I'm glad it is still close on weight.
It looks ok but I don't care for the asymmetrical looks. Just me though, nothing wrong with your bow, Eric.. Looks nice.
Eric, posted this on the LW too.. it looks good. Maybe a tad stiff coming out of the bottom dip. But it should be fine if you don't want to mess with it and lose more weight.
Most importantly, it's towing the line of the string hand fulcrum, maybe just a hair to the left of the line? Hard to tell in that pic. Working the dip area of the bottom limb would bring it over ;) But a 'slightly' stronger bottom limb is not necessarily a bad thing in a bow with a shorter bottom limb. Your limbs are still close to optimum harmony, but your bottom limb is just a hair stronger than the top (in spite of what the braced profile looks like)...
So, what do you think of this tillering method so far? How about a picture of you drawing it by hand? How does it feel when drawn by hand? Shoot it yet?
That is how I would MUCH rather see folks draw their bows on the tree... the way they'll shoot them... not drawing them from the middle of the handle.
I was going to post a picture of the last recurve I did for comparison, but after I looked at it, thought perhaps I better not, it's a tri-lam, bamboo backed, with a lot of deflex, so the profile is quite different than yours, and I don't want it to mess with your tillerin' eye.
Nice work by the way. I'm working on a recurved osage selfbow right now too... VERY similar to yours :thumbsup:
its not left of the line, right on it. if you can see the line in the pic you got better eyes than me! i dropped a plumb line down from where i hooked to the string and attached my bottom pulley right on the line. then tied the string to the pulley hook. so i just have a white string for a line. works well. full draw pic tomorrow i promise!
(http://i1174.photobucket.com/albums/r607/jdscifres/echatsbow.jpg)
I think I would work the right limb in the middle and the left limb in the fade a little bit.
John thanks! I always like your picture magic. seeing that, i agree, but i want your honest opinion on this, would you do it if you wanted a hunting bow, and one pound could make the difference between a hunting bow and a target bow? what im really asking is, in your opinion, will it be just fine if left as is, even if it could be better tillered by your suggestion?
Jeff, post a picture of Raven, it's more like Eric's bow.
John how the heck do ya do that super imposed image, please?
Eric, ok, I was seeing things then. I thought I saw a faint dark line... maybe it was a shadow of the string or something? No, trust me, my eyes aren't what they used to be :(
That's even better yet, you went for it and sync'd them as best you could.
Yes, I would but I also have about 40 bows in the queue :) It will be fine like that if it shoots well.
Roy, I use Photofiltre freeware. Google it. I copy the right limb and then paste it back into the image. Make sure not to hit "Enter". Right click on pasted portion and click "Paste Options" set Opacity to 50%. Right click on pasted portion again and then hover over "Transform" and select "Flip Horizontal" and then drag pasted portion to align with other limb. You may have to rotate it slightly. Rotate by right clicking and hover over "Transform" and then click free...
Fine movements can be done with the arrow keys. When it's how you want it, hit "Enter".
That clear?
Here's the bow Roy's talking about. It's a tri-lam, bamboo, yew, osage.
(http://img.photobucket.com/albums/v312/Jeff_Durnell/Raven/BYO60_zpsd31a6ff1.jpg)
(http://img.photobucket.com/albums/v312/Jeff_Durnell/Raven/BYO79_zps66606e05.jpg)
(http://img.photobucket.com/albums/v312/Jeff_Durnell/Raven/BYO80_zps8e4b1ae1.jpg)
Jeff thats awesome. was planning on trying a tri lam next, but im not 100% satisfied with this one so i may try again to make a selfbow i am really happy with. hey did i ever say all you guys are the best? well ya are. feel like im standing on the shoulders of giants. :notworthy:
i mean how many bows did you guys build before you knew half of what you have taught me?
i mean how many bows did you guys build before you knew half of what you have taught me?
Just one for me:) :laughing:
Thanks, John. I will check it out.
A BUNCH... :)
Roy you're an a$$! :laughing:
Well thanks, SquidyBoy:)
Actually, I've been timing my bow limbs since early on. It just made sense. I didn't have a thorough understanding of it back then, in fact bows still hold many lessons for me. I tried to fully comprehend everything Dean was talking about, but it just took me some time, experience, and experimenting of my own. Early on, the main thing I was trying to do was build a bow that sent an arrow without porpoising, built-in good tuning, because I reasoned that was a bow's entire reason for existing in the first place... to shoot an arrow well, but eventually I learned it was much bigger than that.
Eric I think that bow is looking really good.
Jeff, also really like the look of that tri-lam. I'm working on a form now with a very similar profile I'm hoping to use for some boo backed bows and also maybe for a glass bow if I get the itch.
Eric, I just saw some pictures of your stave that brings something to mind and thought I should mention it... I noticed an area in each limb that looked 'weak', so as I usually do before I give tillering advice, I looked to pictures of your bow unstrung, their 'starting line' before I judged them. How EACH limb bends, and appears as it's being drawn, is, and should always be, relative to IT'S unbraced profile. In other words, if they are different unstrung, those differences should still be detectable at brace, full draw, and anywhere in between. If an odd shaped, humpy limb is tillered to form a perfect arc, it does not have stresses distributed evenly along its length.
As I looked at your pictures, I saw both the one prior to ANY heat correction, with a big hump in one limb near the inner limb, and a big hump in the other more towards the outer limb... and the unbraced picture after the corrections, with much of those humps gone, but not all.
While I think the double image picture is a great tool for bows with limbs of same-profile, your bow is a good example of one which may not be the best candidate for its use, since your bow's limbs should NOT be tillered to the exact same shape... in order for each of them to have their stresses evenly distributed.
Does that make any sense?
One more thing... though it might seem your bow is taking some set if compared to the picture of it fresh off the caul, I think it's actually some of those big humps trying to come back a little bit... which is hard to avoid. They were some big humps. Nothing to worry about... just saying.
(Edit)double post.
This one was a mirror image of the other one :)
Jeff it makes sense. thanks. put about 30 shots through it yesterday. feels good. little light but i will get over it. its gonna be very quiet when its all finished and string silencers and all. sorry no full draw pic yet, i can only play with bows when im all alone, and its hard to get a pic taken. i will get one.
(http://i1308.photobucket.com/albums/s608/echatham/101_2681_zps825a3a65.jpg) (http://s1308.photobucket.com/user/echatham/media/101_2681_zps825a3a65.jpg.html)
got a little over a hundred shots through it and tiller hasn't changed. verified the timing too. gonna start finishing now.
Nice. She's sittin' good and square in your hand, so you must have your holds mimicked pretty close on the tree.
Good job, man!
Can't wait to see her all dolled up.
Can you post an unbraced pic? That lower limb is working a whole lot midlimb. Is set concentrated there?
Eric, post a picture for John of that stave before you did any heat corrections please.... and an unbraced pic of it now too if you could.
I was just re-reading Vol. 4 of TBB (page 135) and came across the part about using combed flax to regain lost weight, and thought of this bow. If you do end up changing anything and lose weight, that might be worth looking into. Sinew too, I suppose...hopefully you can avoid either though. It's a great looking bow!
Pretty nice, Eric. You have come a long way in a short period of time... ^5
(http://i1308.photobucket.com/albums/s608/echatham/IMG_20130821_093253_619_zpsc43b5c6d.jpg) (http://s1308.photobucket.com/user/echatham/media/IMG_20130821_093253_619_zpsc43b5c6d.jpg.html)
(http://i1308.photobucket.com/albums/s608/echatham/IMG_20130830_190917_002_zps7fdbb43f.jpg) (http://s1308.photobucket.com/user/echatham/media/IMG_20130830_190917_002_zps7fdbb43f.jpg.html)
not sure how i feel about these different length limbs. probably going to go back to same length limbs on the next one. thinking about trading my fedora R/D bow for a stash of staves. my bow wood guy thinks he wants it. going to ohio first week of Oct to hunt with him. just don't have any interest in glass bows any more.
I don't look at it like having different length limbs. I build bows from the fulcrum, The upper limb and the lower limb start at the same point and they are even length, There may be less wood bending in the lower limb but it is still the same length.
Eric, just keep making bows. Lots of bows. Of all different types. Don't make your mind up just yet.
I'd hold off on getting rid of the glass bows. If you liked 'em once you probably will again. Let the puppy love with wood wear off before you go doing anything you might regret later.
There's tons of osage in Ohio. Find someone who will let you cut a tree or two.
It's all good and it's all fun...
Unlike what John said, I love wood bows and I don't care for making glass bows. But hey, that's just me...
John, i did like em once.... but i think it was just a stepping stone. i bought my first ever traditional bow, a recurve, in November last year. sold my brand new compound a month or so after. then i bought a longbow and loved it more than the recurve. recurve has been on the shelf since then. then under Roy's guidance i built my first wood bow. theres no going back for me. i know theres plenty of osage in ohio, and i already talked to Matt about cutting a tree, and he said we could, but im probably gonna be to busy hunting.
Eric, I think you should make a symmetrical bow now and use your new tillering tree methods and understanding to build a bow with synchronized limbs and then make some comparisons between the design styles with regard to static and dynamic balance and shifting fulcrums. Some new things will try to reveal themselves.
I look at limb length like John does... "I don't look at it like having different length limbs. I build bows from the fulcrum, The upper limb and the lower limb start at the same point and they are even length, There may be less wood bending in the lower limb but it is still the same length." That was well put.
I dont know where youre at in Ohio, but the places I cut osage in Ohio grew excellent stuff, wayyyyyyyy nicer than anything I've ever seen here in Pa just two hours away.
John, did you take notice of the unstrung profiles of his bow? And do you see why I wouldn't advocate tillering them to the same exact drawn profile?
well im going to stay a week with Matt Fout in Waverly. you guys might even know him. goes by Whitefeather on the LW. both my staves came from him, and the next probably will too. Jeff next one is going to be be symmetrical and i will definitely pay attention. hey this is off topic, but while i got all you pros tuned in, i always want my bows to be straight after shooting in, no string follow.... just something i wanted to be able to do and haven't pulled it off yet. is there some guideline you guys use when heating in reflex to end up with a straight bow? for example my kid's bow here:
(http://i1308.photobucket.com/albums/s608/echatham/IMG_20130802_233412_573_zps7cfe1917.jpg) (http://s1308.photobucket.com/user/echatham/media/IMG_20130802_233412_573_zps7cfe1917.jpg.html)
thats hickory and only about 20@20", but it ended up straight and stayed that way after several hundred shots... i want my bow to do the same! :banghead:
Eric, building a bow that stands straight after being shot-in isn't as simple as heating in the right amount of reflex. It often helps, but there are a bunch of other factors too that need to work together to make it happen. You can reflex the livin' snot out of a stave, but if too many other factors work against it, it may follow the string in spite of your efforts. Some of these other factors include, but are not limited to...
Moisture content of the wood: If it's not adequately dried, it's gonna take unnecessary set... even if everything else is done well. Here I'd like to add proper care of and storage of wood after being cut. Whitewood especially, can degrade quickly after being felled if not properly cared for, which can lead to unavoidable set.
Design specifics: If it's too narrow, thick, or working limbs are too short and such relative to draw weight, draw length, abilities of the wood, etc... it's going to take additional set.
Inherent quality of the individual PIECE of wood: If, for instance, you have two pieces of osage, and make identical bows with them, with the only difference being ratio of early to late growth in the annual rings, the bow with the higher percentage of more dense, clearly defined late growth is going to take less set than one with more early growth saturation and less dense late wood.
Tillering: If each inch of limb isn't contributing equally to the work being done... if some is working harder than others, the overworked areas will be under more compression and tension which can cause set. Also in regards to tillering, if a bow reveals an area that is too stiff or too weak during tillering and you don't address it, but draw the bow farther, you're causing unnecessary set in the areas that are forced to work too hard. ....So it stands to reason, the more your eye for tillering develops with experience, the sooner you'll recognize problem areas, get them corrected, and the less set your bows will take in the end.
Wood species vary in their ability to deal with tension and compression stresses, but if designed accordingly, many of them can be made to take little if any set in a finished bow. The less they're able to deal with this stress, the wider, thinner, and longer they have to be to accomodate certain design, draw length, and draw weight requisites.
That's why I prefer osage and yew. Generally, I like short, narrow, deeply radiused bows, of 60+ pounds, and osage and yew can deliver the goods if I do my part.
I don't mind my bows taking a little bit of set... that way I know I'm not overbuilding them.
Keep in mind during these discussions that 'set' and 'string follow' aren't synonomous. You can induce 4" of reflex into a stave and if it stands perfectly straight after shooting-in, it took 4" of set, but has no string follow.... so you still could have done things differently, if you wanted, to minimize the amount of set it took.
Our ability to coordinate and balance all the factors involved in making wooden bows that are neither overbuilt or overstressed is dependant on, and develops with, the skills and understanding gleaned through attentive, inquisitive, experience.
do you mean to say that theres more to this than tillering?! :biglaugh: :laughing: just kidding i know theres alot to it... more than i understand yet and maybe never will. but i do learn alot from every bow and my mind is on the next one as the finish dries on the current one. you know what i can't understand... the guys that come on here and build one bow and disappear. how do you not get addicted to this? I know its not for everyone i guess.
QuoteOriginally posted by Bowjunkie:
John, did you take notice of the unstrung profiles of his bow? And do you see why I wouldn't advocate tillering them to the same exact drawn profile?
Honestly, not really. When I digitally overlay a pic like I do, it isn't necessarily to say the limbs should be twins. In fact, it would be impossible for them to be. It is merely a teaching tool I found useful as I learned to tiller as a reference for even bend throughout the limb. On this bow, the lower limb is bending disproportionately in the middle third. The inner and outer limbs aren't doing their part. Because it is osage, it will survive and I am sure be capable hunting tool. And if shooting manners are good then it is fine as it is. There's lots of ways to skin this cat.
Yeah, most folks don't get crazy about it like some of us. It's not for everyone though. I've found a number of guys are enamored by the notion of making their own bow but when they find out about the learning curve, and the personal investment required, they tend to shy away.
I just came up from the shop. I glued up a symmetrical hickory-backed osage. Glued in just a little reflex. It's a test bow and I want it pretty much straight when it's done.
Also pondering the next upgrade to my tillering tree and have some parts ordered.
Ah so your gonna make a symmetrical bow? Did you over build the top limb slightly? What's the specs on it? Looking forward to this build, Jeff..
I see you shoot three under, Eric. You did have the tree setup for three under tiller I assume? After looking at the full draw shot again, the bottom limb seems a tad flat right out of the fade. Or is it just my old eyes? :)
Eric is your head spinning yet? LOL
Geeze, Old man, calm down. It's just two flat pieces of wood glued together so far. Quartersawn hickory .100 thick and pretapered quartersawn osage about 7/16 to 5/16. Might get the handle glued on later today, but it's not gonna be a quickie. I've got an 80 hour work week kicking off tomorrow :(
Ouch on 80 hours.. Think I might take next week off and build anutter bow:)
alright guys its done. starting a new thread for the finished pics.