Looking for a little help with this Serviceberry bow

[burtonridr]

So I have a bad history of failing during the final tillering of small diameter sapling bows. I'm not sure if it poor design and trying to get to much out of it, or if I'm messing something up during the final tillering after stringing.

I've just roughed out this bow, it is 56" long, 1.5" wide limbs for the first 12" (from end of fade to beginning of taper)of the limb and then tapering to about 3/4" wide at the tips. The handle is 4" long, fades are 3" long. The limbs are about 0.64" thick along the entire length. Because the stave was about 1.5" to 2" diameter to begin with, the back has a crown, the belly is flat at the moment, so "D" profile.

right at about where the taper begins, each limb has a natural deflex (away from shooter) in it.

With the current thickness of the limbs they bend, but it is still fairly stiff. I have not strung the bow yet.

I guess what I'm hoping for is an explanation of how to tiller the limbs from this point without ending up with a weak bow or a compression fracture like the last locust bow I tried. I've had good success with other styles of bows, I just cant get these small diameter saplings to come out right and I'm not sure why.

Thanks in advance.

[mikekeswick]

Unfortunately your stave is too short.
A 56 inch bow with a stiff handle would be maxed out at around 24 inches or so.
Find a stave about 68 inches long to start with. This is for a 28 inch draw.
It sounds like you are descxribing reflex in your bow not deflex. Reflex is a curve that makes the back concave when viewed from the side and a deflex would be a convexity.
to learn how to tiller any bow I would suggest buying the Traditional Bowyers Bible vol1. It has an excellent chapter on tillering.

[LittleBen]

I think mike is right on as usual.

For comparison sake, I built a hickory sapling bow years back that is about 1.375" wide, 54" long, very short stiff handle, maybe 4". Steam bent recurves, almost no reflex, carefully tillered, and I was about to squeeze out about 40#@25". Might even be a pound or two less.

The limbs of this bow are around .4" thick at the fades, and maybe .25" - .3" at the tips.

You can definately make a bow from a short sapling, but you're going to have to compromise somewhere.

I suspect if I tillered my hickory bow down to maybe 30#@28" it would probably survive and shoot OK. Yeah ire not going to get a stiff handled, full draw, durable, hunting weight bow from that stave .... just ain't gonna happen.

[burtonridr]

Ok, well I guess this will be a good opportunity to make a new bow for my 13 yr old. He needed a new one anyway

I will have to measure his draw length tonight and see if it will be a good fit for him.

I appreciate you guys confirming what I wanted to deny so badly. I really would like to get a full draw bow around 56" with at least 40lb, but it sounds like I need to look at either bend through the handle or maybe much wider limbs?

I've seen a few of the bows zion built from service berry, but his descriptions don't usually include all of the dimensions and details. So roughing out this bow has been slow because I wasnt sure where to slow the process down. I got a little lucky and made an educated guess to start slowing down at around 3/4" thick. I got the limb thickness down to about .8" and started to really slow down, switched from a sure form rasp to a course bur style rasp, started checking for propeller twist, really dialing in the limb thickness across the whole length to make sure it was even and free from possible hing points, etc. After all that, I'm now at .64" and starting to see a noticeable increase in flex with each pass on shaving wood off. I'm trying to be really careful not to tear a grain or anything that might cause a hing at this point in the process. Working service berry has been interesting with its twisting grain, really have to pay attention to how you shave the wood, it really wants to tear if you shave with the grain.

[burtonridr]

Unfortunately your stave is too short.
A 56 inch bow with a stiff handle would be maxed out at around 24 inches or so.
Find a stave about 68 inches long to start with. This is for a 28 inch draw.
It sounds like you are descxribing reflex in your bow not deflex. Reflex is a curve that makes the back concave when viewed from the side and a deflex would be a convexity.
to learn how to tiller any bow I would suggest buying the Traditional Bowyers Bible vol1. It has an excellent chapter on tillering.

Thanks for clarifying the reflex vs deflex, I always seem to get them mixed up.

I've borrowed TBB v1 from the library before, it is such an awesome book and the section on tillering is awesome. I really should buy the book, I would reference it a lot.

[burtonridr]

I think mike is right on as usual.

For comparison sake, I built a hickory sapling bow years back that is about 1.375" wide, 54" long, very short stiff handle, maybe 4". Steam bent recurves, almost no reflex, carefully tillered, and I was about to squeeze out about 40#@25". Might even be a pound or two less.

The limbs of this bow are around .4" thick at the fades, and maybe .25" - .3" at the tips.

You can definately make a bow from a short sapling, but you're going to have to compromise somewhere.

I suspect if I tillered my hickory bow down to maybe 30#@28" it would probably survive and shoot OK. Yeah ire not going to get a stiff handled, full draw, durable, hunting weight bow from that stave .... just ain't gonna happen.

Thanks for the info on your 54" hickory bow, did you keep the limbs full width out until about half of there length? Or did you begin the taper from the fades? Was it a pretty high crown on the back?

[burtonridr]

Just a quick update, I finished tillering the bow tonight. Came in pulling 30lbs at 24" which is perfect for my son

I'm not super happy about the tillering job, I think it might be off a little.... I had to eye ball it because my dog ate my tillering jig. Maybe I will post a pic tomorrow and get a few opinions.

I will have to cut some more staves this weekend.... I will have to see if i can find a 68"+ stave like mike suggested, but they are tough to find that size. I may have to experiment with splicing at some point.

[aaron]

One option for the next bow is to make it bend in the handle. I make almost every bow bendy handled. This increases the working limb and lets you draw further than a stiff handle. I often build up a cork handle to make it fit the hand and retain it's bend. With a good sapling and good tillering, a bow like this could be as short as 62 and still draw 28. In theory, you could go as short as 59, but you would need an exceptional sapling and perfect tiller.