Bow #2 Status

Sorry no pictures for this post.

This is a quick update. I am calling bow #2 done - all except for the cosmetics part. I have it at about 48 lbs at full draw of about 28 inches. That is a little too much for me, but I plan on working through it. I've shot about a dozen arrows with it and got serious left arm bruises as a result. I'll be buying an arm guard soon.

Bow #4 (Emily's bow) is not going to work for Emily because her draw is too long for a 60 inch bow, which is what #4 is. So, it's going to be in the hands of a grand-kid soon. The problem there is that it's still too strong for an 8 year old by quite a bit. I think.

I had another kid's bow in work and it exploded on me. So, it is in pieces now. Firewood. My mistake was a poor gluing job on the handle. The surfaces were way too smooth and consequently when I had it on the tiller and drew it about 10 inches the handle popped off and the sudden pressure on the stick bent it violently and it exploded. I needed to rough up the surfaces a lot so that all that glue in there actually made the bond that it was supposed to make.

In the meantime, my 3 year old grand-son (one of them) said, "Grandfather, can you make me a tiny bow?" So, I've got one near ready for him. It is probably too strong yet for him to pull all the way back to his 15 inch draw, but that may not matter, since he won't care as long as the arrows fly, which they will. At 10 inches it has about 18 pounds of pull. He should be able to do that.

Bow #2 Getting close

Here is a photo of bow #2 strung (braced) at a draw of 25 inches pulling at 42 pounds or so.

I'm glad I have this photo to look at. Now I can see much better that there is more tillering work to do. I had thought I was basically done. But now I can see that the right limb (which was the one I had weakened too much initially) is too stiff from mid-limb down to the tip. And the last foot or so of the left limb can use some bending as well.  I've pulled it all the way to 28 inches and it reads around 50 lbs of pull. That is probably more than I want for myself and so hopefully taking off more wood to even things out may get me closer to the 40-45 pound range.

I have to get this thing done since our church has an all-church-last-Sunday-of-the-month meal this upcoming 29th and my bow is supposed to make an appearance there. I don't mind the bow being shot by anyone and everyone, but I do wonder how many of my arrows are going to be lost. We'll see.

Meanwhile, I've made significant progress on bows #3, #4 (which cracked and is now retired or in moth balls) and #5 and #6. I'll give a report on those later. Basically, I've got 4 bows all being worked on at the same time. 

Here is the latest photo showing the progress on bow #2.  You can see that it certainly is bending a lot further. I actually thought I made another bow-ruining mistake. I got quite impatient trying to get to the milestone of moving the limbs 10 inches at 30 lbs. of draw weight. It seemed that no matter what careful belt-sanding I did, I made zero progress towards the goal. I eventually got more agressive with my technique on the belt sander and got there. Unfortunately, I way overdid it on one of the limbs and introduced a very noticeable hinge in the right limb. So, I had a gross imbalance plus I thought I might have overdid the one limb just like I did the bow #1.

This photo is after I worked on just the stiffer of the two limbs, leaving the overworked one completely alone. This helped even things out. I also then took a little off the weaker limb but scrupulously avoided the overworked area.

Today, I went to the woodshop and using my tiller stick, the long string (i.e. the bow is not braced with a short shooting string) I carefully removed wood in just those areas that weren't bending as much as in the weakest areas. So, now I think I have a pretty good tiller. In fact, what was the weaker of the two limbs is now bending a tad less than the one that was formerly the stiffer of the two.

On the tiller stick with the long string, I have it moving about 17 inches. I don't know the poundage but I don't really care that much about it right now. I just want to see a more or less perfectly smoothe bend in each limb. Again, I just got this work done and don't have a new photo. But I think it is pretty good. I actually strung it with the short string and pulled it all the way back as if to shoot it. It is definitely harder than 40 lbs. Probably closer to 50. I expect that 45 lbs. is a reasonable draw weight for my physical capabilities. 

I am not able to put up a photo (I haven't taken any photos of them yet)  showing the nocks and the tip overlays. I have discovered that my nock work is weak. If you look at photos on this site, the same one I referenced earlier, you can see what nice nock and overlays look like. Mine are pretty crude but hopefully not beyond hope.

Also, I've begun bows number 4 and 5. I dreamed up a design for kids bows that uses a maple core sandwiched by two strips of Ipe wood. The core is one-quarter inch and the strips are 3/32 inch thick. The idea is to emulate the way that typical fiberglass bows are made. But in my case here, the Ipe is being used in place of the fiberglass. Ideally, when everything is glued up, the result will be an easy-to-draw kids bow that requires no tillering.  I discovered that these dimensions on a 56 inch bow result in a bow that is probably too hard for an 8 year old to pull. The solution, rather than scraping or tillering is to use a thinner maple core. So, bow #5 has a three sixteenth inch core. Hopefully, that will bring the bow weight more in line with what a kid can pull. If that doesn't bring it close enough then I will go with an even thinner core of maple or maybe leave off one of the Ipe strips (on the belly) 

Stay tuned for photos on those bows. 

Bow #2 Installment 3

Bow #2 is now a bit further along. I've tapered down the belly (and sides as well). I used a big old belt sander at the wood shop. The wood shop I'm referring to is the very well equipped wood working club that is owned by the Seven-Oaks community association where I live. I pay $240 per year and one of the things it gets me is access to all of the clubs sponsored by the association. The wood working club has everything I think I'll ever need to make bows. I will still do most of my work in the garage, but for many things the shop is a godsend. I'll use the table saw, radial arm saw, drill press and belt sander quite often.

One of my stringing booties ripped right through. I knew its days were numbered, and yesterday it ripped. So, I either had to fix the bootie or make a new one or cut nocks in the bow and use a real string. I chose the third option. I then made my first serious mistake on this bow. I cut one of the nock groves backwards. It didn't finish the whole cutting job, but I cut a pretty deep groove with my three sided file. I decided that the damage, while certainly at least cosmetic, could also cause a potential structural problem. Therefore, I glued on my first pair of tip overlays. These are probably mostly cosmetic in themselves, but in this case they are going to shore up the damage my mistake caused. See the next installment for a pic.

As for bending and tillering, I don't think there's a whole lot of change happening there. I did fix my pulley system problem. I installed the pulley too high up on the 2x4. See pic below.

I busted it off the 2x4 today and moved it down as low as it will go. Now I have room to pull the string plus the draw scale, hopefully, to the full draw length of about 30 inches. We'll see.

Bow #2 Continues

Here's my jig in action. This is the glue up of two Hickory backing strips on what's gonna be bow #3.  You can't really tell but what's going on here is actually quite orderly. 

Below is a close-up of the jig. What you see here is a trough 1.25 inches wide in which the Ipe bow belly fits snugly. Those bisquits there (I subsituted plywood strips in place of these bisquits since these were pretty flimsy) are spaced exactly 1.5 inches apart. That means that the two butted up Hickory backing strips will be squeezed in place, exactly centered on the belly. The belly actually is taller than the top of the trough so the strips hang out in thin air over the edge of the belly. The problem with my first jig (this is my third attempt at making a jig) was that there was nothing to keep the belly centered under the stips. We tried, as we frantically were gluing things up, to keep the belly centered and the strips over-hanging equally. We didn't succeed. Consequently, bow #2 has backing strips that aren't centered very well on one of the limbs.

Now this design solves the centering problem. One thing you have to make sure of is to not glue the bow to the jig, what with all the excess glue all over the place. We addressed that with painter's masking paper.

This is a bow #2 at 30# and 5 inches of string draw. I believe I see that the second half of the right limb is a bit stiffer than the corresponding area on the left. What do you think? 

At this point, nothing has been taken off the belly. Note the leather booties at the ends of each string.

Bow #2

This bow deviates in one significant way from the failed bow #1. This one has a wood back. The first one's back was dry wall tape. Also, the first bow is made out of Red Oak. This second bow is made out of Ipe for the belly wood and Hickory for the backing reinforcement. 

As of this writing, I am about 1/3 into the project. And I have been at it for almost two weeks. This time my bow woods, both of them, are hopefully going to benefit from the fact that Hickory and Ipe have a pretty straight grain. 

The dimensions of this bow are 68 inches x 1 1/4 inches x 1/2 inch approximately.  Of that 1/2 inch thickness, the Hickory back contributes 1/8 inch. The Hickory board from which the backing strips came was 3/4" thick. The 1/8" strips were quarter sawn from it and thus are 3/4 inch wide. Since a 3/4 inch wide strip won't cover the back of a 1 1/4" wide bow, I decided to get a little crazy and laid two strips butted up against eachother as a backing strip.  However, two 3/4 inch strips are 1/4 inch wider than the 1 1/4 inch Ipe plank. On top of that, my Hickory strips, to be butted up next to eachother are not 68 inches long. I could only reasonably cut strips long enough for half the length of the bow. 

This makes for a tricky glue up of 4 Hickory strips to the back of the Ipe. In fact, its nearly impossible for a two handed person. 

So, I made a jig that holds everything in place while the strips are glued on. Actually, the jig I made is only long enough to do half a bow at a time. 

I'll provide some photos in the next installment so you can see what things look like.

First (failed) bow

My first bow, which I began sometime in early February 2009, was built step-for-step after the plans detailed by Sam Harper here.  I'll tell you right up front that it ended about 2 weeks later in failure, as the bow developed a crack on the middle edge of one limb that went up through the back. There were other problems that would have probably doomed this bow for other reasons had not this crack appeared. Actually, one of the problems with this first bow began before I even got the Red Oak board home from Home Depot. It was a lousy piece of wood. Although I pored through the stack (while the guy with the orange vest stood by wondering why I couldn't decide on a simple piece of wood) there just weren't any sample there that really stood out as suitable. Not that I am an expert, of course. However, the one I picked just didn't have very straight grain.  For that matter, there weren't any there that weren't warped in some way or another.

Below is my tillering rig. I opted for the pulley system mostly for the convenience. Some say that tillering on a stick which you hold in front of you with notches on which you hook the string can be dangerous. I don't really buy that especially as I get better at making these things.

The other failings of this bow were a severe twist along both limbs that probably amounted to 10 degrees. There was no solution for this problem. Also, one limb had a nasty hinge that I introduced due to careless tillering. That too was fatal, since to get rid of it would have resulted in a bow way too weak to be of any good.

Lessons learned from this build were to plan more carefully and to proceed more methodically.

My next bow build will be posted shortly.