Input needed for tillering

[slathrop]

Aloha everyone!  I'm new to this board but have been building bows for a while now.  I'm currently building a 60 inch ipe with maple backing and a handle 6 inches long.  The maple is 1/16 inch thick at the middle with a slight taper to the ends.  I put a slight recurve in the bow and am now tillering the bow.  I have included a photo of the bow on the tillering tree and would really appreciate any constructive input from others.
I think the right limb is a little stiffer than the left limb which looks to me like it's curving correctly at this point.
Any thoughts?

Mahalo

[n2everythg]

yep I would agree. right is bending a bit more.
Looks like you are still on a long string. I would brace it low now the tiller might change a bit when you do.
If it stays the same I would scrape the left limb mid limb a bit to even it up a bit.
then I would go back to the right limb and scrape it a bit right out of the fade and the outer 2/3rds as it is almost looking like it wants to hinge in the right limb. Might look a lot different braced tho. do that first.
How much weight you got right now?
looking good so far though.
wade

[slathrop]

mahalo for the input.  I did like you suggested and used my cabinet scraper and 50 grit sandpaper to take both limbs down concentrating on mostly taking out the stiffness in the one limb.  Here are some pics of the after with the short string on the bow:

[n2everythg]

that is looking pretty darn good.
I think you haven't gotten many replys yet cause this is posted in the 'how-to's and build along section rather than in the bows section.

but I think you are getting close now. bend looks pretty good.
what are you pulling it? I would guess at 17-20 inches now?

in the drawn pic (last pic) your left limb is stiff about 2/3rds the way out. get that bending a bit more.
remember to exercise the bow each time after scraping.
do you know what weight it is now pulling at that dist?

you are getting close. keep working it.
wade

[Chadwick]

In the braced and drawn pics, the left limb appears to bend closer to the handle than the right limb. I'm betting you'll need to work on the outer third of the left limb, then the right limb to even them out.

[slathrop]

That's it, I quit!    This one broke about a 1/3 of the way from teh tip on that limb that had the stiffness.  This is the 4th bow I've broken and I seriously can't take anymore.  I really thought this one had a chance too.  I shaved down the stiffer limb with my cabinet scraper and could see the curve coming out really nice when I put it on the tillering tree.  I then shaved down the other limb to get them to start matching.  After doing another round of shaving on the one limb, I exercised the bow and then put it on the tillering tree to take yet another photo to see how the bend was coming out.  Just as I opened the door to the house, SNAP!  Right where the bend of the recurve is on the one limb I needed to keep working on.

I tell you, I just can't do it anymore!  I put hours upon hours into these freaking things and they jsut keep breaking!  I don't know what I'm doing wrong!

[AKmud]

Bummer!  That looked like it had potential...

Don't give up, maybe try another wood combination.  I made several red oak board bows backed with fiberglass sheetrock tape and then went to unbacked hickory.  I have also done a few out of unbacked ash.  Out of the 12 bows I have built now, I have only blown up 3 and 8 of the 9 remaining have been shooters! 

Keep trying (and posting pics!)

[slathrop]

Bummer!  That looked like it had potential...

Don't give up, maybe try another wood combination.  I made several red oak board bows backed with fiberglass sheetrock tape and then went to unbacked hickory.  I have also done a few out of unbacked ash.  Out of the 12 bows I have built now, I have only blown up 3 and 8 of the 9 remaining have been shooters! 

Keep trying (and posting pics!)

I'm trying to stay positive and I've never quit on anything in my life, but man it really breaks my heart when this happens! 
When I first started using maple to back my ipe bows, I learned that the bakcing was too thick at 1/8 inch so I started cutting the backings to 1/16 inch with a taper to about 1/32 at the tips.  My father in law is a carpenter and he has recommended I use a marine epoxy instead of titebond III to back my bows as he says that the oiliness of the ipe may be causing a problem with the adhesiveness of the titebond III.
Do ipe bows really need backing?  Or are they strong enough without?  Also, what do you think of backing an ipe bow with silk or linen?

Mahalo Nui Loa

[DustinDees]

it is suggested to wipe down ipe with acetone or something similar before gluing. personally i like hickory for beginning the stuff is really tough, and the only failure i have had with hickory was because of really low moisture content and a rough back, red oak is good as well and can be found at many hardware stores cheap. dont give up. and remember dont pull the bow another inch untill the tiller is spot on. the first inch that u see a difference in the limbs stop at that spot and if you cant figure out why they look different take a pic or step away from it for a few, but take it off the tiller tree, dont leave the bow on the tiller stick/tree for any length of time that it doesnt have to be there. keeping the bow drawn can damage the wood. make sure round the corners on the back, any sharp edge can lift a splinter easier than a smoothed backing. im falling asleep and im sure im rambling, good night. Best of luck.

Dustin D

[Far East Archer]

Hello

If you look carefully you can see the break going along the grain run out side.
This is reason for break I believe....also, maple wood is relatively light backing, it should be used with similar density wood or lighter like juniper or cherry.

Ipe wood is very compression strong, so, I think it may have overpower the maple and cause break...
You should use hickory wood or bamboo as these work very well with ipe

[n2everythg]

Dont give up.
Know it is frustrating as H@#$!.
Most of us here had multiple failures during the learning process.
I broke or ruined my first 5 bows before I got my first shooter. Now I got a stack of decent bows in the corner.

A couple of suggestions.
Get rid of that tillering stick. when you are tillering and pull the bow to whatever length and leave it there you are putting a lot of strain on a bow that probably isnt ready to be held in a drawn position yet. make a new tilering stick with a pully and a rope. that way you can stand back. see where you need to work and hold the bow in that position no more than 30 sec.. I usually hold it much less.

second. you never told me what weight the bow was pulling at that length.
My guess is you didnt know. You have to know how much weight you are pulling and never pull more than the intended draw weight. I usually pull much less as you can figure out approx how much weight is left by calculating roughly 3 lbs per inch. so if you are pulling 15 inches at 30 lbs you know if you take no more wood off and are going for a 30 " draw you will have 15"x3# more weight or 45 more #s so you now have a 75# bow.

those limbs look pretty thick to me. course you are kinda narrow in width. try getting a bit wider and spreading the forces out on the next one.

keep with it. I think you got pretty close on this one.
luck and later
wade

[DustinDees]

ok its the next morning and im not all zoned out. looking at the break closely i do believe you had a grain run off in the maple, whatever material you have for a backing CANNOT have grain run off. the grain lines have to be as straight as you can find them all the way from end to end. on the belly grain is way less important, but on the back the tension will split any weak spots. hope this helps.

Dustin D

[George Tsoukalas]

That right limb in the first picture just was not bending well. It was bending too much off the fades and the last 10 inches were way too stiff. A couple of observations- (1) take the tillering stick and use it for a tomato stake for the reasons N2 gave. Nice job, N2. Make up a rope and pulley.  (2) Never pull a stave beyond what it takes to expose a problem. (3) Go get yourself a nice straight grained red oak board. After long string tillering back it with silk, burlap or linen because you are a beginner. (4) Don't get discouraged. It took me 14 tries to get shooter. There a buildalongs on my site and info on boards. Jawge
http://georgeandjoni.home.comcast.net/~georgeandjoni/