An experimental warbow

[markinengland]

I just started a new experimental warbow.
The belly is a nice piece of Ipe, the backing a good bit of hickory.
I'm aiming for 110lbs at 30 inches.
I've glued in 5 inches of reflex but tied down at about 2/3rds along each limb to concentrate the reflex more at the tips. I'm hoping this will avoid any possible hinges near the tips and allow me to carefully reduce the width and depth of the tips to get a nice smooth typical warbow shape at brace and full draw while maximising performance for distance. I plan on leaving the handle section stiff for about 12 inches.


This is the belly stave marked out. I covered the Ipe with masking tape so I can see the lines a bit more easily.


Here the belly and backing are shaped and rounded ready for glueing. The belly stave floor tillered well so I left it as it was.

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A bit hard to see but here is the belly and backing glued and bound with a rubber strip.


Here the bow is in the form. 5 inches of reflex at the tips but tied down about 2/3rds along the limb to 2 inches so the reflex is concentrated in the last part of the limb where it narrows and depth reduces most.

I should be able to take the bow out of the form on Saturday and unwrap it. I have a feeling it may be a bit of a monster but there is plenty of wood in depth and width that I can remove if necessary.

Will post more as the build progresses.

Mark in England

[duffontap]

Sweet.  Keep posting pics of your progress.  Good wood combo.

       J. D.

[DanaM]

What J.D. said.

[markinengland]

Steve,

I do actually have two nice almost black pieces of Ipe and some perfect bamboo with a view to making a record breaking flight bow. Within the time I have for bow making I have been experiementing to make a really good flight performing bow. This nice chap asked me to make him a bow like that a terribly long time ago, but I am getting worried he may now to too old to pull such a mighty bow! Would a flight record still stand if the bow were built as part of a Zimmer Frame and used a pulley system ?
The last bow I made worked well. Ipe with bamboo backing, out of the same piece of Ipe as this one. It could have made 110lbs but for a slight error in cleaning up through the line instead of to the line near one tip when cutting the basic tapers. Long central stiff handle with narrow relatively stiff tips making it a short bow on a long handle. It came out at 60lbs at 30 inches once I had allowed for this annoying tip hinge. The bow was outshooting others 20 to 30lbs heavier and it wasn't being pulled to full draw by a long way. This bow went to one of my brother-in-laws as a trade for a nice knife.

Mark

[markinengland]

I took the bow out of the clamps, undid the rubber strip and cleaned it up this afternoon.
Looks nice and has about 2 inches of reflex at the tips.
There is more than enough wood there for 110lbs at 30 inches.
Bow bends quite nice and I reckon tips will be just about stiff enough once cleaned up and worked a bit.

Mark

[Rich Saffold]

  Well that is looking a bit more "normal".

[markinengland]

Richard,
Almost dissappointing isn't it! Sometimes quite a few inches of glued in reflex can dissappear, but you can tell it is there by the increased stiffness of the bow. Of course every now and then just to throw you off you'll glue in five inches of reflex and it will still all be there when it comes out the clamps! I think that very small differences in the thickness or strength of the backing makes a big difference.
Glued on some horn for nocks this morning so will be able to shape them later on.
Also did some basic shaping in tapers for a 150lb Ipe warbow. I'll wait to see how this experimental bow turns out to glue that one up though.
Now off out to cust some dogwood for arrows.
Mark

[Badger]

     Mark, the bow is looking good, I am convinced that you don't need all that reflex for record breaking performance. My bows are getting straighter all the time and concentrating more on where to concentrate the bend and controlling the mass, Are you going to tiller this bow into the arc of a circle or with a stiff mid-section? How long is the bow?
    Mark, what you said about shooting off a frame is a good question. Present flight rules are more about the flight shooter and not the bows are bowyers so mush be shot by hand. A lot of us are more into building bows and want to see their potential. A hand-shot bow, shot by an experienced distance shooter or speed shooter can outshoot the machine shot bow considerably as the bow hand will be in motion adding up to about 20 fps to a shot. The only way I know to duplicate this for a test would be to shoot the bow through the machine and set is so a 4" spring is compressed against the bow when it is at full draw, even 1/2 draw would likley work, this would act like an active bow hand. You would have to check the speed of the bow shot in a static mode and then shot with the spring loaded bow to verify the actual advantage, I would set the spring to add about 10 fps as this would be average for a good flight shooter. Be kind of cool to start a registry for tested bows on both sides of the pond.

[markinengland]

Steve,
This bow will be a basic full arc bow, or as close as I can get it as this is what David wants. I will leave the centre slightly stiff.
I am slowly building up my knowledge for the "record breaker" or at least what I hope may be one.
I recently made a 60lb longbow with a 20 inch stiff handle and it worked well. Out of the sister stave for this one with a bamboo backing. Came out of the glue up flat though I put in a couple of inches of reflex. It was a swap for a knife from Danny, one of my brother-in-laws. The bow seemed to perform very well in terms of distance. Danny also did quite well with it first time out at our field club so the formula must be failry stable to shoot.
I guess we could agree a standard shooting machine. This would allow some comparative tests and results on both sides of the big pond. Could be fun. It would have to be failry portable so I could transport it to the filed I can shoot in.
Mark

[Rich Saffold]

Mark, I think it will end up faster,and I think the original reflex would be good on a fast 40# bow that long.  My experiences are the same as Steve's, even though we can compare bows on occasion at the S. Cal. gatherings. I find my fastest bows are very close to straight as well.

My latest slender longbows have been r/d in fashion with the bend concentrated closer to the handle than usual with very straight outer limbs..

I can see this shooting machine looking like a big crossbow with interchangeable limbs

Rich

[Badger]

Mark, just for the heck of it I figured out what I would shoot for on mass for that bow, with a 12" semi stiff center I allowed for a 6" center stiff. For a self bow it would be about 34 oz, for a backed bow I take off about 10%Which would put it close to 31 and then if you are making it for flight I would try and get it down to about 28oz or 29 oz. Do you know what the stave weighs now untillered? Steve

[Justin Snyder]

Mark, Steve and Rich, thanks for posting this.  It is exciting for me to watch someone build a bow, but for you guys to post your thought process as you go through it is immensely profitable to the rest of us.  I wish I could understand the thought process a little better in the design and building for better performance. I understand Steve's mass formula, but it is such a small portion of the process.  Thanks again, Justin

[markinengland]

Richard,
I'd be interested to see some pics of your RD longbows.
Steve,
Right at the moment the bow is at between 29.5 and 30 ounces. I'm guessing some will come off that in tillering but not too much, but there again it may be underweight! The bow is somewhat overlong but will be safer in use for it. I hope the weather is good enough tomorrow to get outside and do some more work on it.
Justin,
I love the making of bows and the shooting of them, but one of the best things is that you can think them through during any work day. It is interesting to see if the thought process actually works out in practice, and of course mistakes are good learning chances, even if they do get a bit boring at times! I have spent quite a time thinking strange thoughts, putting a lot of hours in and made some lovely broken bows  So far these have all been experimental ones I have made for me, which seems a little unfair.
This bow should be failry safe, it will just be interesting to see how light I can get the tips with the etra bit of semi-recuve reflex at the ends.
Mark

[Badger]

It is kind of facinating trying to figure out what makes these things tick. A year ago I built an osage elb about 140#, didnt take any set to speak of but had lousy early draw weight. Since that time I have built many others whith much lower draw weight but having much higher tension at brace. I am convinced that the key to good performance with these bows is to not overstrain them durring tillering, wether or not it manifests itself in string follow is irrelevant compared to the brace tension we maintain. Steve

[duffontap]

wether or not it manifests itself in string follow is irrelevant compared to the brace tension we maintain. Steve

Wow, that's so simple but totally true.  This is interesting guys.

       J. D. Duff