ELB build along - osage

[Shaun]

This stave was about 1 1/8" square by 72 1/2 long. I drew a grain follow center line - this piece is clear but wavy. Then I marked 5" increments from the ends and laid out profile with each segment 1/8" less in width. This makes the center about 1 1/16" tapering to 1/2". The first pic shows this profile cut and the same taper laid out on the side profile.  I cut the top lay out square to the back (chased ring) surface.

 

Make the same tapering layout on both sides and cut with approximately 10 degree lean of the back surface. This prevents cutting too deep on the opposite side where the wood is twisted. After making cuts from both sides you will have a ridge in the middle of the belly.


 

Application of power rasp (edge sander) removes this ridge and general shaping towards the arched belly shape and general view towards leaving a tapering in both width and thickness from center to ends.

 

With the bow flipped back side up you can see that this stave is not straight. Since we are headed for a rounded shape (ELB rule is that the bow can be no more than 8 to 5 ratio of width to thickness) it is MUCH easier to tiller a straight stick. A flat bow resists bending sideways - much less so in a rounder shape.

 

So, onto the cull with heat gun and clamps.

 

[Shaun]

I like to use a piller tiller system before brace height. This allows me to get back and sit looking at the arc, then mark with pencil and take off wood where there is less bend, flat spots. Here is the stick off the cull with induced backset and nearly straight.

 

My belief is that you can do little harm to the stave before reaching brace. The bar clamp allows continuously variable draw and is more solid than using a long string on the tree or a tiller stick. Here is the first bending. As always, stop as soon as you can see a flaw in tiller and correct.

 

I see flat spot in the center and about 1/2 way out the right limb.

[Shaun]

Correct and repeat process until the arc is pleasing.

 

Still a little flat in the center, just to the left of center, and last third of left limb, but getting real close. At this time I return to the heat gun as some of the original waviness has reappeared  during tillering - this is common with heat adjusted wood. These smaller and area specific adjustments are made one at a time on the bench.

 

[Shaun]

After re straightening, continue adjusting tiller on the posts. I switch from 40 grit to 100 grit on the edge sander and start to work on smoothing and tapering in both width and thickness as the tiller progresses.

 

When it gets this close I cut string nocks and try first brace. I use the pillers to brace as the bow is still to heavy for push pull hand stringing. Love the moment of first brace!

 

With this method 90% of the build is completed before the bow is ever drawn past first brace. Now is the time to put it on a tiller tree and/or start shooting it in. As the wood is worked it will change and need re adjusting of tiller. This is also the time to check draw weight and start reducing towards desired finish weight and refining aesthetic lines. Also, minor adjustments of limb alignment will be needed by either heat or tillering (cutting material from off center of the width will make the limb bend towards that side). Here is the bow nearly complete - needing finish smoothing and more shooting in with minor adjustments as they appear.

 

 

This bow is still slightly heavier than the mid to low 50's I want, but final tiller adjustments and sanding will bring it in. Time to shoot it a bunch and get the wood to finish settling in to its working shape.

 

Another note; I mentioned the ELB ratio of 8/5. The center of the limb is under more twisting stress than the hand held center or the tips, so this area is often shaded more towards the 8/5 flatter profile and the handle and tips left round. This makes the limb cross section progress from round center to flatter mid limb and back to round at the tips in most ELB bows.

[Shaun]

Further thoughts on piller tiller system: Before bending past fistmile brace height little set or fiber damage is likely because so little deflection has been made. It is yanking a bow back to 20" while it shows tiller flaws that induces set and hinging. By correcting tiller flaws in the very early stages of bend this is avoided. It does leave the wood untested and further bending will create new flaws as the fibers stretch. These need to be corrected as soon as they show during the working in by shooting (short draw) or working on the tiller tree. In the first brace picture on the posts, the arc looks nearly perfect. This will change as the wood works - that is the last 10% of tillering required until full draw is reached.

[K.S.TRAPPER]

Pretty cool Shaun    

You make it look easy  :D  

Tracy

[4est trekker]

Love that tillering idea!  I've never seen it, but it does make a good deal of sense in many ways.  Thanks for sharing.

[Dan Landis]

Thanks for the build along Shaun, I'll be trying the piller tiller on my next one.....Dan

[Stiks-n-Strings]

Great build along Shaun. I'll have to try that tillering method (minus the sander, as I get in a hurry to often as it is)

 Can you post some pics of the 2x4 stands and give us some measurements?

[KellyG]

that is one great looking bow.

[coaster500]

I've got a chunk of Sassafras to practice on...  I'll give it a try.

Thanks again for posting  

[snakebit40]

 Really cool way to work out your tiller. Thanks for sharing!

[Buemaker]

Thanks for sharing, I must say it is an interesting tillering method, I am gonna give it a try. Bue--.

[4runr]

Sweet looking bow Shaun.

A local fella has got me thinking about building another bow. I like your method.

[Walt Francis]

Shaun,
That is a great build along.  I love the tillering method and will give it a try this winter.

[Osagetree]

Me too!

[mwosborn]

Thanks for sharing - I to am going to try the piller tiller method.  You do make it look easy!!

[Roy from Pa]

Shaun, that is fantastic. I love the concept, a very ingenious idea. I will be trying that real soon. Thanks, Roy

[Living_waters]

Thanks shaun!
I just brought home some white oak staves to make some incised decorated Delaware bows out of and the bendy handles have been my nemesis, either I end up whip ended or too stiff in the handle. This looks real promising as a solution for me.

[cooper2003]

Nice build along. This is the type of bow I am hoping to make as soon as I master a few board bows.