"SweetGrass" - Finished r/d all bamboo build along

[Jeremy]

I glued up a nice tri-lam r/d all bamboo bow this week.  68" total length (66-1/4" NTN), 1-3/8" at the fades, 1/2" tips.  The boo backing has a gentle taper to midlimb and the taper increases to the tips.  The boo belly is the full 1-3/8" out to midlimb and then tapers to the 1/2" tips.  The result is a limb that gets progressively more trapped out to midlimb, and less from midlimb out.

     

     

She came off the form with about 2-1/2" of reflex and after floor tillering and longstring tillering out to 10" still has all of it.  She's 60# at the 10" and ready for the short string.

As this is my first r/d bow I'll be posting tillering pics as I go from here out.  She's starting to come round, but still needs more work midlimb out... at least that's what she looks like on the longstring - we'll see what the short string tells us.

[Jeremy]

For anyone interested in what type of form I use and all that, check out my previous thread... I used the same form and methods, just added some pieces onto the form to get the profile I wanted.

 http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=015896;p=1

I cleaned the shop... so it won't be confused with the mess that is Scifres shop!        

Not sure how much I'll be able to work on her this weekend, so be patient with me guys.

[Huntrdfk]

That's has a nice look to it Jeremy.  Looking forward to watching this one.


David

[mich-mtnman]

i had some problems last week with a heavy weight bamboo lam project.
 im looking forward to seeing this thru as well.
 great start !

[Jeremy]

First stringing at a low bh:

 

Upper limb (Left) is stiffer than lower.  Needs work midlimb especially.
After a little work here she is 50# @18":

 

[Jeremy]

I like the way the lower limb (on the left in bottom pic) is coming around.  The upper limb still needs more work midlimb... it's also still too stiff - just under 1/4" negative tiller at midlimb at brace.  Most of that should be fixed by getting the middle 1/3 bending more.  Sill looking good at the fades and out at the tips though (to me anyway).

Tillering these r/d bows takes some getting used to!  Anyone see something I'm missing (or think I'm dead wrong)?  Mr. Scifres I'd appreciate your input... I'm headed to your site now to see what these things are supposed to look like!

[Jeremy]

Worked on the upper limb a bit more and increased the bh to 5".  Here she is at about 20":

 

Upper limb still a bit stiff, but only 1/8" negative tiller now.  Another few rounds of the Bowyer's Edge later I increase the bh to 6" and here she is at about 22":

 

The tiller is dead even here.  The upper limb still needs work midlimb out.  What I'm seeing (I think) and not liking is the wood working too much right past the fades.

I'll work on it a bit more midlimb out on both and try getting the bend out more toward the tips.

[Jeremy]

Actually, I think I'll hold off on working too much on tiller until some others weigh in on it.  I'll start getting the tips ready for the phenolic overlays.  

My wife tells me we're going to a movie tonight, so there may not be any more pics until tomorrow.

[Slim Buttes]

looks good, I'm know expert but it looks like the right limb is stiff mid limb, and the left is stiffer at the fade. If the limbs are even length, the right tip is lower than the left tip. I think that is do to the stiffer area at the fade on the left limb.  

Hope I helped, if not, I WAS NEVER HERE.

I got one in the shop that I'm going to post pics of later today.

[Jeremy]

The lower limb is shorter... I think by 1-1/4", though I'd have to go measure to be sure.  Also, b/c of the flat area on the handle the bow is slightly tilted toward the upper (right) limb.  That kind of screws with how it looks.  The left fade is actually working more than the right; I've had a big "W" at that spot since I initially thinned the limb when floor tillering.

She feels good in the hand while short drawing.  She does want to pull toward the upper limb a bit, but the tiller is dead even so that'll be fixed by getting positive tiller on the upper.

I'm happy with the way she's looking at this point.  I still have room and weight to spare to bring her into tiller, so I'm not too worried (yet).  Just need to get more wood working midlimb out on both...  if I screw it up you can be sure I'll delete the thread quickly!  

[horseapple]

If I squint realy hard I can see tiller:)  other than that you need to put something behind the bow so we can get a better view of both limbs bending without all the distractions from behind... how about a white bedsheet...

Joe Don

[Keith Deters]

Jeremy,  It's looking real good so far.  You've been working the right spots as far as I can tell.

I don't think the fades are bending too much.  The deflex sometimes makes it look that way.

Tips are a little stiff at this point, might not be at a longer draw.

[Jeremy]

I (mostly) shaped the phenolic tips - that's tough  stuff!! - and worked on the outer limbs some.  Here she is braced at 6":

 

And 55# @24":

 

[Jeremy]

To me, midlimb out on the lower(left) limb is looking a little flat.  The tips on the upper limb could probably come round more also.

Hope the cardboard behind the bow helps some JD... my wife may not let me back into the bedroom if the good bedsheets disappear!  :(  

After a thorough workout on the tiller tree and a half dozen shots at about 24" draw, her tips are dead even with the handle after unstringing.  There's 1/8" positive tiller on the upper @ midlimb and she's well behaved at release.

[Jeremy]

All the selfbow guys out turkey hunting today or are you    ??      

After a bit more scraping and finishing the tips - I really need to thin the phenolic down before gluing it on next time    - here she is at 26" draw:

 

[Jeremy]

I think it's about time to put away the bowyer's edge - possibly even the scaper - and bring her into final tiller with sand paper.

The outer 1/3 of both limbs could use a little more work, I think.  But she's downright sexy with her gentle curves      

That'll probably be all the tillering for today.  I'll smooth out the handle a bit more and maybe glue on an arrow rest.

[mich-mtnman]

very cool, im still watching.

[Keith Deters]

I like it.  It looks like the upper limb is on the left?

I think you're right about putting down the edge tools.  

I looks to me that you could move your clip on the string more towards where the arrow nock would be.  That may weaken the lower limb a bit.

The outer limbs of these bows usually show a bit stiff.  I like to leave them thick and narrow them to get the mass weight off them.

How are you doing on draw weight?

[Jeremy]

Keith, the upper limb is the right limb.  Going back to the original pic on the camera I see the clip is a little low, so the upper limb is actually a tad weaker than the pic shows.  There's about 1/8" positive tiller at brace.

She's somewhere between 55-58# @26" right now, so I'm on track to making weight... it's nice when that happens!

I'll shoot it a bunch tomorrow and see if/how the tiller changes and then ease her to the final draw and tiller.

[John Scifres]

She's stiff from just outside the fade to almost midlimb on the left.  Your right tip starts getting pretty stiff just outside midlimb.  Left is stiff just a bit farther out than that.  Right limb is stronger than left.