Tillering Check and a couple of questions - continued....

[mwosborn]

Here is one of the bows I am currently working on.  Hackberry static curve - 64" ttt, 1.75" to midlimb then currently tapered to 3/4".  Stave was cut and sealed in 2011.

Pictures are at a brace of 4.5" and then drawn to 13".  Currently 36# at the 13".  Final picture is immediately after unbracing.

This is my first static and I am going very slow with the tillering.  Have been very careful to keep limbs bending very similar as I reached this brace.  Have not exceeded 40# and have slowly exercised limbs after each wood removal.  It looks to me that the outer 1/3 of the limbs need to be bending more - wanted to get opinions on this as I not sure on a recurve like this.  What you think?


Secondly, the limbs are starting to take some set (even being careful)  the right limb more than the left.  My original plan was to make an unbacked bow.  However, it looks as if I might be better off putting some sinew on the back.  Opinions on this?  I need to get to 27" draw and I am shooting for a 45-50# bow when finished.

I plan on narrowing the tips when I get closer to finished - will be asking questions about this if I get that far.

Thanks for any help!

Mitch

[Pat B]

Mitch, I've not worked with hackberry but everything looks pretty good. Both limbs from mid limb out could bend more.

[huisme]

Yep, I think the outer limbs could to bend quite a bit more, which might help your set problem.

As long as you leave them nice and thick you can make the tips as narrow as you're comfortable with. I think my current project for my grandpa has tips 1/8th at the knock, but they're twice as thick as the outer working limb. Nice and light.

[IdahoMatt]

Yes mid to outer.  Right side looks a little more stiff than the left.  Can't wait to see it done.  Looking great so far

[Danzn Bar]

What Pat B said........
DBar

[mwosborn]

Thanks for the quick replies guys.  Guess I can head back to the garage and work on those outer limbs!

[mwosborn]

Removed some wood from mid limb to curve.  Increased brace to 6" and pulling 38# at 16".  I think it is bending better.  Still stiff in the outer 1/3 from what I see.  Left limb is a little weaker than the right.  Increasing the brace caused a tiny bit more set.  What you say?

Thanks - Mitch.

[burchett.donald]

 Did you heat temper the belly?

[H Rhodes]

I was going to ask if you toasted the belly too.  It seems like you are really taking your time and it looks like it is coming along good.  If it were mine, I would keep on tillering until you are within a few inches of full draw, and if the limbs are bending evenly, give it a good toasting and a slight reflexing. 

  It reminds me of a sinew backed recurve that someone posted a while back that turned out good, but 64 inches is too long for a sinew back to me.  You sure have some good looking hooks bent into that one.  Good luck with it.         

[MWirwicki]

As it stands your bow is between 60-65 lbs, if you were to pull it to full draw.  Don't pull it there yet, but this should give you an idea of how much wood removal its going to take to achieve your 45-50 at 27".  You're very close and your tiller is beginning to look real good.  It may be just a matter of evenly removing a bit more wood to get to your desired poundage. 

Yes, many of the guys who do a lot of hackberry toast the belly, on a form.  It helps the hackberry maintain its profile with minimal set.  I'm not sure though if its not too late to do this.  Maybe some belly toasters (Marc St Louis, Blackhawk, Pearl Drums, Ryoon) will chime in soon on that topic.  See the chapter in TBB-4 on the topic.  Good luck!

[PEARL DRUMS]

Id suggest tempering it now. If you don't? You will have excess string follow and set and wont be happy with hackberry. I think the left limb looks nice and right is stiff half way.

[SLIMBOB]

Sweet looking bow!  Temper it now and take the set out as you do.  Very nice.

[Mark Smeltzer]

First of all that is coming along really nice. I think the advice to get the outer third working was right on and also heat treating the belly but I would only heat treat the inner third. Hopefully stiffening up the inner third of the limbs will transfer more movement to the outer third where it needs just a touch more bend.
Just my 2 cents, I've done it before and it has worked for me.

Mark

[mwosborn]

Thanks for the suggestions! 

Pearl - i used a lot of what you have in your build-along to help me - good stuff!  I did heat a little bit of reflex into the limbs after I had it roughed out (didn't toast it dark like in the build along - just afraid I would burn the crap out of it).  In hind sight, I think that the limbs where still to thick when I heated - they where probably about 5/8" or maybe a bit more.  Would it be ok to still go ahead and toast the limbs now?

Mitch

[PEARL DRUMS]

Thanks Mitch. Id toast it now if I was working it. No more bending until you do though. You cant really burn the wood if you don't try to. It takes a bit for the wood to start turning color to start with, burning it takes much longer. My pics where from a junk camera I had at the time, it wasn't that dark in person. Make it look like an over-done marshmellow. I hold in one spot 3-4" away until it starts darkening nicely, then slide the gun ahead about 1" and repeat. It keeps the heat even and the added stiffness even. It will take about an hour per limb, roughly.