Pyramid bow Tillering approach

[RayMO]

I have made a half dozen BBO (Dean’s method here) and several flat self bows using hickory staves, some have been shooters but I really have not been satisfied with any of them. So I am looking for a simpler approach that results in a good bow. I know that some may argue that dropping trees and splitting staves and pulling on draw knives is great fun, but all it every did for me was make me sore.

Here is an approach I have been thinking about, have not tried it just thinking about it, what do you think?

1.   Get de-crowned board from saw mill (not to hard to do in Mo and a lot easier than splitting logs). Any good hardwood would do here, (Ash, cherry, maple, etc.)

2.   Layout the Pyramid shape on the board, going down to 3/8 on the knock end. I am thinking 2 inches at the widest point, but the exact dimensions are not that important to the procedure, say 68 inches long.

3.   Leave the cut out blank maybe 1/2 inch thick (uniform thickness no taper)

4.   Here is a part I am not to sure about, I would like to put bamboo (maybe hickory) on the back also and glue in about 3 inches of reflex. Not so sure how that will work without a tapered blank?

5.   Here is the part that is a little different: From what I understand the Pyramid should bend to a good circular tiller (assuming a uniform blank) and draw weight should be achieved by uniformly reducing the thickness of the belly. It is my plan to simply use a jointer for this (looking for easy here, no facets no bowers edge).

6.   If all goes will (that’s funny) I will have a bow at this point. But a circular tiller with whippy ends is not my idea of a sweet shooting bow, so I would then plan on adding an overlay to the grip and overlays on the belly ends to stiffen up the ends and the middle.

Anyone every tried an approach like this?

[**DONOTDELETE**]

I did a Pyramid style bow from a home depot board I tapered from fades to tip, tips being .5" thick. I didn't back it nor did I reflex it.

If Your adding reflex I would taper it so you can get the bend of the reflex, well that is what I had read. O I did my with Red Oak.

[**DONOTDELETE**]

My Avatar is the same bow after I finished it. It is sitting at 51#@24" and is 70" N2N

[RayMO]

mysticguido

Thanks for the input, nice looking bow. I was thinking the same thing about the backing. Anyone else?

[George Tsoukalas]

Pyramid bows should have a circular tiller. Wide near handle wood should be doing a big share of the bending as opposed to the tips. The trick to tiller such a bow is to not tlet the handle bend too much as that might make it shocky. Mysticguido's bow is an example of an elliptical tiller. Jawge

[John Scifres]

1/2" is too thick. Start with 3/8 and make sure your profile is perfect and you shouldn't have to do a lot of belly tapering.  Most of the tiller in a pyramid bow is accomplished through the taper in the sides.  If your wood is good, desing is solid and your technique is flawless, you probably won't have to belly taper at all.  I made a pyramid red oak in about 10 minutes coming straight off the bandsaw tillered.  It was 1/2" but 72" long.

[RayMO]

Thanks Jawge, I was hoping you would jump in here. Leave the handle wood thick during the weight reduction process, got it.

What's your thoughs on backing? Not to do or not to do, but puting in reflex during glue up.

RayMO

[RayMO]

Just saw your post John. Ok, 3/8 and not 1/2. That is exactly what I was thinking also, just use a jointer to reduce evenly along the limbs and no tappering on the belly thickness.

[Glenn Newell]

Ray if you are going to use bamboo for a backing I find it best to shape up the bamboo to it's finished dimensions and pre-taper the bamboo down to the bow tips before I glue it onto the bow. It might be easier to use the hickory as backing for the first one as you can shape it up when it is glued onto the bow, unlike bamboo...Glenn...

[RayMO]

Thanks Glenn,

It never occured to me that you could shape/reduce a hickory backing after it is glued. I have only used bamboo so far and you are pretty limited with it after the glue up.

I am kind of confused on the backing issue.

Most agree that the thickness should be tapered if you are going to put reflex and a backing on. However, the Pyramid bow gets most of its shape (tiller) from the shape of the limbs and I wonder what a taper in thickness would do to the tiller of a Pyramid bow? To me the advantage of the Pyramid design is that you do NOT have to mess with a taper in the thickness.

I guess somethings you just have to try.

Anyone made a Pyramid bow with backing and some reflex at glue up time???

[John Scifres]

You are making this harder than it has to be.  Start carving.  Stop thinking.  The beauty of a pyramid bow is its simplicity.

I wouldn't necessarily back it.  I prefer a selfbow.  If you are doing bamboo get Dean Torges' video, "Hunting the Bamboo Backed Bow".  

Why do you want to back it?  If you want simple, selfbows are it.  If you do the selfbow, go with 1/2" thickness.

[Glenn Newell]

Ray if you do any bow with bamboo I think it is essential to shape it up so that you can pre-taper the bamboo and take the stress off the outer bow limbs and reduce some string follow. Bamboo is probagly one of the harder backings to work with but it does look and perform nice that's for sure...Glenn...

[George Tsoukalas]

Ray, I never did a bamboo or a wood backing. Like john, I like selfbows too. I do back some bows if needed. I prefer silk, linen, burlap and rawhide. Again pyramid bows need to get that near handle wood bending quite a bit. Jawge

[Glenn Newell]

George I like all of my bows bending near the handle. The bow will store energy if it bends near the handle the most and bend all the way to the tips but bend gradually less, some styles of bows will vary on this but basically I like to see them bending coming off the handle. For pyamid bows I prefer a selfbow myself.
I do find it hard to get the near handle timber bending when the width of the limb flares out to it's widest measurement only 2 inches up from the handle, I like to take the flares up to 5" above the handle it is more gradual transition from the handle and not as abrupt, I find that style much easier to get the near handle timber to bend...Glenn...

[RayMO]

Thanks for all the great input I really appreciate it.

I had an old hickory stave in the basement that I took the back off of years ago. I cut it out in a Pyramid shape Saturday. 68" long 2 1/2 wide to 1/2 inch. Have not done anything with it yet.

Last hickory bow I made that was a shooter was back in 2001. The lower limb exploited on me. I always felt that the wood got too dry in the house during the winter (it was sealed). Made me wonder about the durablility of selfbows without backing.

Oh well, I also have about a half dozen hickory selfbows from years gone by that have too much string follow and at least a half dozen of Dean's BBO which the tiller is less than perfect on. I keep thinking one of these days I will get a wooden bow that I am satisfied with, but then maybe that is not possible.  :D  

I have always liked a bamboo backing because I believe the stuff makes a bow more durable, but the bows I have backed with bamboo have all been 64" (osage belly) and less so I don't have much experience with 68" and longer.

I am not going to back this lastest attempt  :D  here we go again.


RayMO

[Linc]

Ray,  Is the reasoning for the hickory backing to induce reflex to the limbs? If so, you don't need thickness tapered backing. Parallel is perfect for a pyramid bow. Just glue it up into a reflex. Then shape and tiller as you would for a straight limbed pyramid. Just my 2 cents worth.

[RayMO]

Yes, linc I was just trying to stop the bow from taking a set. I could steam a slight reflex in but that would actually put more stress on the back of the bow.

I was trying to accomplish the following:

1. A bow that is very easy to tiller, hence Pyramid shape. I was even thinking board bow and tiller (really just reduce weight) with a jointer. Simple and repeatable.

2. Put the backing on to prevent set and add duability to the bow.

Now, I know there are a lot of different opinions about this by guys that know a whole heck of a lot more than I do. In the TBB it is sort of concluded that backing is not need for bows 66" and longer, I don't know....??? I guess when you have build 68" bows and had one break and several others take sets you begin to think backing is a good thing no matter how long the bow is.

The real bottom-line is that I am just trying to come up with a "good" shooting bow that I can count on and reproduce each time. With a lot of guys it is the challenge to take a stave with a lot of character and by great tillering and patience come up with a great shooter. My objective is kind of the opposite here.

Anyone???

RayMO

[John Scifres]

A tapered bamboo backing on a pyramid bow should accomplish your goals.  Once you get the process down, it is more of a science of assembly than the art that stave bows generally are.

However, a glass bow is superior in ease of manufacture, consistency and durability to any wooden bow or composite.  If your primary goals are those, you might want to reconsider your desire for an all-natural bow in general.

[RayMO]

Thanks for your input John. I have made some glass bows also, they are ok but I am not that happy with them either; however, I have drawn blood on more than one occasion with them. You are right that what I am suggesting is more of a science than an art. And you are certainly right about a glass bow being easier to make. Just depends on what you want.

Anyway it is just all talk at this point, after the season I think I will get busy trying it out.

The challenge I am proposing is somewhat different:
   

I am just trying to come up with a "good" shooting bow that I can count on and reproduce each time.

Again, thanks John

RayMO

[John Scifres]

I'd certainly say the Bamboo Backed whatever will do it.  As for "good" shooting, most well-designed and constructed bows can accomplish that.  Most shoot where they are pointed.  In fact, I'd argue the shooter does the shooting, not the bow.  What is it that you don't like about your other BBOs?