Backing Help

[David Holt]

OK...workin on red oak board bow #2. This one is 65" NKN, 2.5" at the fades to 1/2" tips. It pulls about 46# @ 27" right now. The problem I'm having is that it is taking alot of set/string follow. Unbraced overnight it has about 2" on one limb andn 3" on the other. When I brace it and shoot it a few times the string follow shoots up to over 3". I poured through the TBBs and I think I may have braced it too high initially and it doesn't help that it's like 100% humidity all the time here in SE Georgia (84 degrees today). I went and bought a heat gun and put a little reflex in the limbs and heat tempered the belly. first time doing that so I probably didn't do a good job. I then left it on the front porch overnight to soak up some moisture (might as well have been green again the next day). The heat tempering did't help a bit. I have put it back into MORE reflex and heat tempered the belly for longer this time and left it in my garage.
 
 
 

My plan WAS to let it sit overnight and back it with rawhide from a chew toy I've had soaking for 2 days:
 

But....It was glued together too well and the long center piece was all glued together and didn't make it through the unwrapping phase  . Not sure what to do now. I have brown paper, satin and some kind of silk blend I can back it with but i don't want to brace it again until I get it backed. Any takers?

[Pat B]

By the time a bows gets 3" of set it is too far gone to change much on a permanent basis. Sounds like you overstressed the bow while you were tillering it. Time to set this one aside and move on to your next. If you learned any lessons from this bow it is not a loss.

[David Holt]

Thanks for the info Pat.  I checked Lowes and none of there new stock is worth a hoot. I guess I'll use this bow and do a little experimenting.  Other than knowlege, I can't let it be a total waste;)

[George Tsoukalas]

David, my first shooter took 5 in of set. It was too wet and badly tillered. Set actually makes it easier to get a bow. Looking at your design I bet it does most of its bending mid limb on. IMHO pyramid bows should be appear rounder in the handle than elliptical. They should do most of their bending where the wood is the widest which is near the handle. Bows that are the same width to jsut past mid limb should be tillered elliptically. Bend should just start past the fades and increase out to about 6 in before the tip. Finish this one up and sweat the set. Set happens.    Jawge

[2treks]

To add a bit to what the other guy's said(I agree 100%) the backings you mention will only aid in protection not performance.
Chuck

[4est trekker]

Actually, the pyramid bow should have elliptical tiller to maintain optimum performance (this according to both Mark Baker and my own finding.  Here's a link to a thread that contains Mark's comments on this very subject:   http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=40;t=000085.    It's a few pages long, but has some nice information in it if you search it out.)  I built a lot of pyramid bows early on with arc of circle tiller and experienced bad set.  Once I started following Mark Baker's advice, my problems disappeared and performance rose considerably.  Arc of circle tillered pyramid bows are easier to make, but I've found they just don't perform as well.

 I suspect David's board had a high MC due to the climate and/or, like Pat said, that it was overstressed during tillering.  I believe that had David's bow been bending more near the handle, the bow would certainly have taken more set (or rather string follow) because set here is much more drastically manifested at the tips.  

Just my opinion.      

[4est trekker]

Hey, David...I see a oak pyramid bow on the bottom of that bow rack in the picture that also looks like the design from the build-along.  Who did that one?  That one doesn't appear to have the excessive set issues you're having on this one.  Was the wood purchased at the same place from the same shipment?  The answer  could be telling of the problems you're having with your bow.  For example, if they're from the same lot, then they would have had very close, if not identical MC at the time of purchase.  If one bow takes excessive set and the other doesn't, then the issue can very well be overstressing during initial tillering.

[David Holt]

Thanks everyone for your comments.  I am your humble sponge!  My wife can't understand how I can stay up to the wee hours reading through hours of threads.  I can't understand how she can read through hours of facebook!!

4est: That is the first bow I made off your buildalong. It is from lowes but not from the same shipment.  Mark (SSBNDOC, pink bow for his daughter) made our first pyramid bows in my garage.  The bow in the rack was made to the specs in the buildalong but it is a little thin do to the aggresivness of my new bandsaw blade.  It is only 40# @ 27" but shoots like a champ.  Im on 65" tall so I tried to make this bow to the specs of your turkey bow. I think I should have exersized the limps during the tillering process.  I pretty much went from band saw to mirroring the limbs with calipers to brace and my brase height was like 7".  I think I just stressed it out to quick.  The excessive set was gone by morning but was back after about 3 arrows.  Still shoots nice, just bothers me to see all that string follow.  I was prety worried about the heat tempering being that it is kiln dried wood and i had never done it before.

Here are pics of the bow after i took it off the board tonight.  I put it in reflex and heat tempered the belly night before last.  I know PAT B said the wood is already trained for the string follow it has taken but it's got some pretty good reflex in it.  It looks so good I'm afraid to put a string on it    

 
 
 

Should i sand down my tip overlays?

 

A few pics of the 40# bow.  I am very happy with this bow.  My first real success!

jaege
would this be an elliptical tiller?
 
 
 

[David Holt]

The yarn string silencers I found in another thread work awsome.  This bow is quiet!

[4est trekker]

David, that bow in the pictures looks fantastic!  Full-draw tiller looks great.  I'm so glad that you've had success!  

And not to answer for George, but that is elliptical tiller.  I designed the bow in the build-along to tiller exactly like that (so good job!).  

Again, great work!