Mulberry stave with questions

[Fred Arnold]

This split was from a larger stave that I still have seasoning and I took this section down to these dimensions over a year ago and let it dry on my rack. I've now decided to spend some time trying to get a bow from it.

75 1/2" L X 1 1/4+" W X 9/16" D. It's well dried and chased to 1 sapwood ring on the back.

The thickness at the sides doesn't   include the crown that I left remaining on the belly. You can see the shape on the end in the first pic.

I've been reading some posts in regards to the mass principle and will readily admit that I don't completely understand it. Figuring that I end up reducing this from it's current weight of 23.5 oz and lose 25% during limb taper (just a guestimate), that would only leave approximately 17 to 18 oz mass weight.

I guess my question is, can I achieve a 45# bow with these specs?

All suggestions in regards to design and how to proceed appreciated.
Thanks, Fred

[PEARL DRUMS]

My advice? Drop the numbers and mass principal stuff and just build the best bow you can. You don't need scales to tell you how well a bow shoots, or doesnt. The only time I weigh a bow is when I think it feels incredibly light, curiosity gets me. Yes, you can easily get a 45# bow from that stick. At that length you have a lot of options. What kind of bow do you want? Long and slender? Or a bendy? Recurve?

[JonW]

I'm with Chris. While the mass of a bow can tell you a lot, so can shooting one. There is nothing wrong with using or not using the mass principle.

[Badly Bent]

Fred, if you want to tiller using the mass principle as a guide I believe that you won't want to take it into consideration until you have it on the short string and bending out to within maybe 6" or so from your target draw length. Then with your draw weight and draw length targeted, and having a general idea of what the mass weight should be for your design (bendy or static handle), you can determine if more wood should be removed from sides to drop mass or from belly to reach full draw or a little of each all while watching draw weight and tiller closely.
Not sure if I'm right about this so if I'm wrong maybe someone will set you on the right path, this is just the way I've processed the info in my mind and again it may be all wrong. I'm more like Jon & Pearly in my approach to building bows but I do weigh mass on each one when finished out of curiosity and to give me a guideline on the next similar style and same length bow I make.

[SLIMBOB]

Same as Pearl, jonw and BB. The mass on a bow you are building can be spot on perfect, and if the tiller is wrong, you got a dog. Mass is off but the tiller is spot on and you got a shooter for the next 20 years.

[Fred Arnold]

PD, Jon,BB, and SB / Thanks for the input I generally try to leave the limbs a little wider with less depth. With a 28 1/2" draw I've been limited to how short I can make the limbs and have been successful with 60" bend in the handle bows but prefer a bulbous stiff handle so the majority of mine have been 64 + NTN.

I have limited experience to know what works and what doesn't. I'm not new but certainly  haven't mastered the craft.

This stave seemed to dictate a long narrow design and I'll have to be carefull to leave more wood on the belly than I have in the past or I'm afraid I'll be way under intended draw weight.

I do have a tendency to end up at the bottom of the scale when finishing bows, meaning that trying to attain 50-55 it'll generally be 47-52.

[JonW]

Fred 1 1/4" is right on being a little narrow for Mulberry IMO. Try an oval cross section on the limbs and you should get what you want.

[Josh B]

I'm assuming that's some of the male mulberry that you harvested a while ago?  If so, it's pretty light in density and 1 1/4" is a bit narrow.  Luckily, you have plenty of length to compensate for that.  45# is doable.  At 28" of draw, I would use a slightly rounded off rectangular cross section  70" ntn with the center half of the bow being the full 1 1/4" width and then straight taper the outer half of the limbs to the tips.  I would use an elliptical tiller instead of full compass to get better all around performance.  Not whip tillered mind, but definitely elliptical.  Your handle cross section will probably be pretty close to square at those dimensions, but that's just a guess. You'll want it to bend a little through the handle, but you can build the handle up with leather or cork to get your bulbous handle.  Josh

If you want to tiller it full compass bend in the handle you can shorten it to 66" ntn, but the longer elliptical will shoot better......usually

[Josh B]

I just noticed the 9/16" thickness part.  Forget the 70" long bit.  Not nearly enough thickness.  I really have doubts about the 66" making weight.  Sorry about that Fred.   I really should pay more attention.  Josh

[Fred Arnold]

Greg, Thanks for the PM.

Jon, the bow is awfully light in the hand compared to other woods I've worked with and I'm going to try the cross section you are referring to. I have an old Keasey yew ALB that has similar tiller.

Josh, I remeasured the limbs and found the top begins to narrow a little sooner than half the distance but it's only about 1/16" so the 1 1/4" will work out from probably the fades to 15" out. I'm going to utilize your recommendation as close as I can.
The black walnut bow you helped me with awhile back turned out to be my fastest bow to date.

I got the heat gun out this morning and did a little correction to align the tips and take some minor twist out of one limb. Then a little rasping and scraping to even things out. I had the stave ready to work and with some floor tillering thought I was ready to look at it on the long string.

My floor tillering skills are poor at best but I seem to be getting better.
Limb on the right is the top limb. It appears to me that the top limb is a little stronger right in the fade area but the bottom limb seems to appear stronger overall.

Josh. I was typing when you posted. It's going to be a bow no matter what and I'll have to take what I can get as far as weight goes. With 14 grand kids there's ways somebody around needing a lighter bow
 

[Josh B]

I'm glad that walnut bow turned out good for ya.  Those dimensions I gave you are just general guidelines.  For the most part, small variations in width are irrelevant.  Just be sure that you keep them in mind when your tillering so narrower spots don't end up being hinges.  That Cobra skinned bow I posted a while ago had a section on each limb where the the width narrowed from 11/16" to 1/2" and then flared back out to 5/8".  As long as you leave more wood thickness through the narrow section it works out fine.  I just used that as an example that small variations are negligible if handled correctly.  Just use what wood you got and It'll either work or it won't!  I hope it works for you.  That sapwood back is gonna be quite striking when the heartwood darkens!  Josh

[Joec123able]

Have a mulberry in the works right now also one ring of sapwood if I didn't have a painful headache right now id be working. Mulberry is a pleasure to work and is super light the heartwood is very pretty and darkens very well