- Hits: 2310
Making your own bow part 7: Construction of a laminated reflex-deflex longbow
In the seventh article in this series, Cleve Cheney finishes his discussion how to construct a reflex-deflex longbow.
> Figure 1: Use a coarse wood rasp to remove hardened epoxy.
OK so your bow has been curing in the laminating oven for eight hours. Switch the oven off and allow it to cool before attempting to remove the laminating press.
Remove the bow form from the heating box. Deflate the pressure hose by pressing on the valve. Unbolt the top half of the form and remove the hose and metal pressure strip.
Now you can remove the bow from the form after cutting the insulation tape holding it in place. You might have to insert a blunt knife under the bow to "pop" it from the mold. Now be prepared for a shock – the "bow" looks a mess but don't panic it always does at this stage.
< Figure 2: 'True' one of the bow side on a belt sander.
Remove as much of the cling wrap and insulation tape as you can, but DON'T take the masking tape off the face and back of the bow just yet. You must leave it in place to protect the bow during the shaping process. Epoxy will have squeezed out between the laminations whilst being compressed by the inflated hose and will have hardened on the edges of the bow making it look a real mess. The next step is to clean this up.
> Figure 3: Draw a centre line along the limbs.
Use a coarse wood rasp to remove most of the hardened epoxy. Switch to a less coarse file as you get closer to the wood surface and remove the epoxy carefully until the laminations become visible. See figure 1.
Now sand one side of the bow absolutely true using either wood files or on a belt sander if you have access to one. See figure 2. Check to see that the side is true by holding it against a sheet of glass or a flat surface. Little or no light should show through. Holding the trued end against a flat surface use draw a centre line along the length of the bow. Use an apron, long trousers, gloves, long shirt sleeves and safety goggles when sanding fibreglass if you don't want to itch. Now draw a centre line along the limbs as shown in figure 3. Note that the masking tape is still on the bow. Take the limb template you made earlier on and lay it on the face of the bow. Line up the centre of the template with the centre line you have drawn onto the bow. Trace the bow outline onto the masking tape.
< Figure 4: Nocking grooves
You must remove all material outside the shape of the bow. The bulk of the material can be removed on a band saw. If you don't have a band saw you can use wood rasps and files or a belt sander.
It's starting to look like a bow at last! You now have the basic shape of the bow. Now I know you are itching to see if the bow bends without breaking – DON'T! – there is work to be done before you can get to that part.
The next step is to cut the grooves for the nock.
Glue a piece of attractive looking wood onto the face of the bow tips with quick-setting epoxy to strengthen them. Use a six mm rat tail file to file the nocking grooves for the string. The grooves must slope down on the back of the bow and almost meet. This is to channel the bowstring to the centre of the bow. Note the angle at which the nock groove slopes from front to back. Nock groove is about three mm deep. See figure 4. The nocks must be straight across each other and of the same depth. The angle of the nock as shown on the right (bottom) must not create a severe pressure point which will cause excessive string wear. See figure 5.
Shape the handle and the arrow shelf with files and sandpaper. See figure 6
The arrow shelf is a slight cutout on the riser on which the arrow rests. Some traditional bows do not have a shelf and the arrow is rested on the fingers. An arrow shelf does result in a more accurate arrow. Good shelf / sight window design will make the bow capable of shooting a wider range of arrows and will be more forgiving of a less than perfect release. There are a number of ways to shape the arrow shelf and three basic types of shelf design as shown in 8igure 7.
> Figure 5: Nocking grooves (2); Figure 6: Shaping the bow; Figure 7: Shelf design
The radiused shelf is common in longbows and recurves and reduces the amount of arrow to bow contact. The flat shelf is common on older type recurves, but is not recommended as there is too much arrow to bow contact. The best option, providing the least amount of arrow to bow contact is the ridged shelf. Additional good arrow shelf design features are beveled edges and narrow sloping shelves which help to limit contact between the arrow and bow. Now before we can get to the final finishing we must tiller the bow – a very important step that we must not attempt to bypass in our excitement to want to shoot our creation! Tillering comprises the gradual bending of the bow over a period so that the glass and wood fibres can have time to orient and "bed" themselves. If this is done gradually the bow will not break. During the tillering process it must also be established that the limbs are bending equally and in the same places and are not twisting.
In the next article we will look at how to make a tillering stick and how to go about the tillering process.
About the Author
Cleve Cheney, hunting and environmental editor of Africa’s Bowhunter is a very well known figure in bow hunting and in conservation circles in South Africa. Cleve Cheney has been in conservation for 27 years, of which 20 years were spent with the National Parks Board – most of it in the Kruger National Park. During the time spent in the Kruger National Park Cleve culled no less than 50 elephants with a rifle and he has hunted most African game during culling operations.
Cleve has also been an avid bow hunter for 22 years and he has an extensive technical knowledge on bows, arrows and broadheads. Cleve is also an accomplished bowyer and has built many recurves over the years. He began offering bowhunting education courses more than 15 years ago. Until recently, Cleve was a lecturer at the South African Wildlife College where was a lecturer and instructor. He has a diploma in Nature Conservations and a MA degree in animal Physiology. Over the years Cleve has written more than a hundred articles on tracking, hunting, survival skills, and bow and rifle hunting. He started an 18 month long professional hunters course at the SA Wildlife College where he trained the first group of professional hunters.
Cleve has trained many bow hunters and his educative articles on how to hunt African game, as well as many other articles on different aspects of archery bow hunting an bush skills has been published in Africa’s Bowhunter, Game and Hunt magazine, Universal Hunter and many other magazines. He has been the lead article writer for Africa’s Bowhunter for more than 14 years.
His book on tracking, The Comprehensive Guide to Tracking: In-depth information on how to track animals and humans alike, is probably the most in-depth study on this subject available. For those who want to learn more than the basics, this book is a treasure trove of tracking information, insights, methods, and knowledge. The book is divided into logical sections: teaching yourself to track; understanding wildlife behavior; identification of tracks and signs; gait patterns and pressure release; blood trailing; tracking specific animals; track, stalk, and approach; bird, reptile, and invertebrate sign; man tracking; and dangers in the bush.