Recently I came across the following discussion http://paleoplanet69529.yuku.com/topic/11885/Questions-about-really-fast-wooden-bows?page=1#.T69m8JOljb4 in the PaleoPlanet forum. Asking if anybody has made a so- called catamaran– bow in the same forum I got some comments focused on very fast wooden bows: http://paleoplanet69529.yuku.com/topic/50882/very-fast-wooden-bows#.T9YPeZOljb4 in general, but no comment about that bow. I guess nobody has made it to date.
Anyway I decided to give this design a try by modifying 2 bows I´ve yet done as flightbows. Maybe you remember my article “Making of a wooden flightbow- 2.5×2 double dragons” and this pic:
I chose the osage bow(2nd from above) and the euonymus bow( at the bottom).
The osage bow was 44lbs at 23″.
First I made a jig for to steambend the long non- bending tips of the bow into an about 30° angle. The bending worked well, osage is really one of the best woods for to be steambent. I left the bent tips in the jig for some hours, then I heat- treated them for to dry and to fix the angles.
Originally I wanted to split the tips with my small bandsaw as Tim Baker has posted it in his comment about the so- called catamaran bow. But when I braced the bow for to check its new tiller, I was heavily surprised by its power and springiness.
I´ve made my experiences with split- limb bows when being the bowyer of a research- project focused on the reconstruction of Boeotian and Egyptian bows. Cause there had been some problems with stability I decided not to split the tips. But for security reasons I added some string- bridges, they are thought to be removed when I´ve done the first shots with the bow.
The length of the bow is 45″, the handle is 51/2″ in length, the tips are 91/8″ in length. The limbs are 13/8″ at the handle and about 1/2″ at the nocks. The draw- weight has increased to 51lbs at 23″. I´ve left the tips in their grown shape. That´s it.
The chronos were done with a 155grs. hex-shaft made of cedar.
The following 8 shots were 240- 255f/s, one last shot for today.
I couldn´t help to do another shot, but ended up with 262f/s.
To chrono a bow is a somehow a tricky thing, it depends a lot on the release of the arrow, I don´t find myself to be very experienced in speed- or flightshooting, I´ve still to practise it much more.
I´ve to thinkover this design and this high speed,actually still enjoying it.
Some adds: I was really hesitating to post the high speed of the bow, cause I´m not quite sure what´s the reason for. I´m still thinking over it and above all I´ve to do more chronos for to confirm the results. And I hope the rainy weather we are suffering from since weeks will stop very soon for to make the flightshoots with the bow, I´m expecting shots at 350- 400? yards.
If I look at the working of the limbs it is very obvious that the further the bow is drawn the straighter the limbs become, so the long tips are not working like static recurves at all. Maybe my wife is right when stating that this bow is built up of 6 bows, 2 longer bows( main limbs), 2 short bows( the transition from the main limbs into the tips) and 2 stiff bows(long tips).
Next BowXplosion will be on the modifyied euonymus- bow mentioned above.
Don´t be to impatient with the crossbow, it is still in the drying state, cause I´ve had to add another sinew- layer for tiller- reasons.