My first build: Oak board kid's bow

[WhistlingBadger]

Well, I decided to take up bow building, because I need another time-intensive, space-intensive hobby.  I'm sure my wife would agree.   

This bow is for my daughter, who is in desperate need of an upgrade from her worthless gl**s kiddie bow.  I'm making it from an oak board of less-than-perfect grain--that's what I have to work with and there's no prospect for anything better in the foreseeable future, so I'm doing the best I can with it.  53" ntn pyramid bow, backed with light linen canvas.  Going for 20# @ 20".   Right now I have it to 20# @ 15".  It feels bendy and snappy and I think it really wants to be a bow.  Sorry for the backlit images.  I'll try to take some more this evening when the yard is darker and the deck is brighter.

Braced:
100_0337 by Thomas Wilson, on Flickr


Pulled to 20# at 15":
100_0336 by Thomas Wilson, on Flickr

Couple questions: 
According to the gizmo, and good old eyesight, I have quite a hinge in the left limb.  I'm slowly rasping the stiff spots to even it out.  Correct?

The right limb looks stiffer than the left, but it's bending almost exactly the same total length.  Can someone enlighten me as to what's happening there and what to do about it?

A couple times this bow has made a *tick sound when I've strung it.  Should I be scared about that, or is that normal, or somewhere in between?

Any other advice/tips/cautions/wild accusations?

Thanks, boys!  Thomas

[George Tsoukalas]

Looks darn good. You should be using a scraper-like tool. Leave the last 8 inches alone especially on the left limb. Count your strokes, exercise and short draw and check with and tiller.
Excellent idea to back it for kids.
Jawge.

[George Tsoukalas]

I don't see a hinge.

The tick sound could be the string settling into the nocks.

Check the belly to look for chrysalis which are little lines across the grain.

Jawge

[WhistlingBadger]

No chrysals on belly, but there seems to be one small crack down the side of a limb, through some of the early wood, parallel with back/belly.  I was thinking about putting a wrap of linen cloth around it once the tiller is done.

[George Tsoukalas]

That could be the sound you heard.
I don't know how bad the grain was initially.
You could try to superglue and wrap it with Dacron set in epoxy.
But giving my daughter a bow with a crack scared me and I've done it.
Jawge

[WhistlingBadger]

So, looking at the picture more closely, it looks like I need to scrape on the middle of the right limb a bit to even it up.  Would you agree? 

I've been using a flat knife blade for a scraper, but the thickness of the limbs was very uneven, with a couple of pretty bad gouges in the belly (did I mention I roughed it out with a chainsaw and a kukri?) so I had to remove quite a lot of material.

Any other advice on how to proceed?  Now that I'm getting close I really don't want to screw it up.

[mmattockx]

So, looking at the picture more closely, it looks like I need to scrape on the middle of the right limb a bit to even it up.  Would you agree? 

I think so and I think I can see what you are calling a hinge, but trust George's eye over mine and trust the tillering gizmo.

Any other advice on how to proceed?  Now that I'm getting close I really don't want to screw it up.

Yes, go very slow and don't pull it any farther than you have until you are happy with the bend (I found this easy to disregard and it is IMPORTANT to fix the bend before moving on no matter how bad you want to keep going). You can perfect your tiller from where you are without ever pulling farther and you risk less that way. When I was finishing up the tiller on my maple mollegabet after shooting it in some I could see the effect of 3-5 light scrapes (so ~0.003-0.005" of wood removal, at most) on the bend of a limb so take very small steps to avoid overshooting where you want to be.


Mark

[WhistlingBadger]

OK, thanks, guys.  How important is it that the two limbs bend identically?  I'm assuming very important.  I won't take it past 16" until I'm happy with it. I scrape a little, put it back on the tillering tree, pull it to 20# ten times, then see how it looks.  It's weird, I do a lot of scraping with no observable effect.  Maybe I have an unusually stiff piece of oak.

[BowEd]

To even out all of those dips you mentioned you could use a 6" sanding block.Look down the plane of the belly at a low angle at a light source and you'll see where its' sanding and where it is'nt.I'd say 60 grit.You'll slowly lose draw weight then too.

[mmattockx]

How important is it that the two limbs bend identically?

It is more important that they bend evenly when drawn by the archer. Lots of guys make the lower limb stiffer (and/or shorter) because it is loaded more than the top limb when drawn by hand instead of on the tree. Before you get all the way finished have your daughter draw it and see how the limbs are bending in the hand. On mine I had one limb a bit stiffer and I didn't want to even them up until I shot it some. I put the stiff limb on the bottom and they evened out when drawn by hand (beginner's luck is a great thing). It was quite a noticeable change and after that I can understand why a lot of guys don't bother with a tree at all once it is bending ok.


 

I scrape a little, put it back on the tillering tree, pull it to 20# ten times, then see how it looks.  It's weird, I do a lot of scraping with no observable effect.  Maybe I have an unusually stiff piece of oak.

Mine didn't get really sensitive until I was nearly done. There was lots of scraping 30-40 strokes then checking with no real change before it started moving.


Mark

[WhistlingBadger]

Got a few arrows out of the bow this afternoon.  Meant to take some pics but we were both so excited I totally forgot.  She can't get it to full draw--I think I misjudged her draw length, so back to the rasp and scraper.  But it does indeed sling an arrow pretty fast, and it didn't explode, so that's exciting.

My original tillering goal was 24# @ 20", coming down to 20# after shooting in and finishing.  Changing that to 23". 

[willie]

There was lots of scraping 30-40 strokes then checking with no real change before it started moving.

seems like that happens more if you exercise the bow while tillering or already have it shot in.
but,  I think once the adjustments are done and the bow shot in, the chances of it going out of tiller with use are lessened.

Paul Comstock wrote about the belly being "compacted"

[WhistlingBadger]

Yeah, that might be it.  Snow in the forecast tomorrow, and I'm back to teaching (virtual) school, so we'll see how it goes.

[Eric Krewson]

I see the hinge in the picture, trust the gizmo, go slower on your wood removal.

[silent sniper]

Thomas, good to see the bow is holding together.  In my eyes I would soften up the mid/outer right limb and just a little bit on the mid/inner limb of the left.  You can measure the string to belly distance at brace height to compare the two limbs for which is bending more. . Overall it’s looking pretty good for your first 👍🏻
-Taylor