Surgical Tubing Recurve Bow Diy

Making a recurve bow with surgical tubing involves a combination of woodworking skills and the right choice of materials. Here's a step-by-step guide to help you get started:

Materials and Tools:

- Wooden stave (hickory, yew, lemonwood, or maple)

- Plastic tubing or handle

- Rubber/surgical tubing

- Modelling/surgical knife

- Nylon string

- Parachute cord or other thick string

- Bow shaping frame

- Tillering stick

- Screw clamps

- Heat gun

- Draw knife

- Sandpaper

- Cylindrical file or flat file

Steps:

1. Cut down a tree with a diameter of around 15-20 cm to get your wooden stave. Alternatively, buy a pre-cut stave.

2. Mark the outline of the bow on the stave, including the handle, riser, and limbs.

3. Use a hatchet or bandsaw to cut out the shape, retaining the desired length.

4. Identify the belly and back of the bow stave—the back faces the target, and the belly curves inward towards you.

5. Test the flexibility of the wood by standing the stave upright and bending it gently.

6. Clamp the bow in a vice and use tools like a draw knife, files, or sandpaper to shape and thin the limbs to your desired thickness.

7. Bend the limbs using the bow shaping frame, ensuring both limbs are bent at the same angles. Secure with clamps and leave overnight.

8. Carve notches at the tips of the limbs to hold the bowstring.

9. Tillering: attach a long piece of parachute cord to the notches, twice the length of the intended bowstring. Pull the cord to test and adjust the flexibility of the bow.

10. Smooth the wood with sandpaper, especially around the handle, and apply a finish like varnish for protection.

11. Attach the bowstring, and your recurve bow is ready!

Choosing the right wood

Maple

Maple is a hardwood that provides a good "snap" due to its ability to store potential energy when flexed, which results in more force being transferred to the arrow upon release. Maple is also flexible enough to create a recurve bow. It is commonly used in recurve bows, either as solid wood or in laminates with modern materials like fiberglass.

Hickory

Hickory is an excellent choice for beginners as it is inexpensive and widely available. It has strong bending resistance, making it suitable for backing, and it tolerates wood run better than most other woods. Hickory needs to be relatively thin when used for bow making. However, it has a high rate of moisture absorption, so it may not perform well in damp environments.

Osage Orange

Osage orange wood is known for its good tensile strength and compressed strength, which helps balance the bow. It also has the unique property of not rotting, even when buried. However, it is sensitive to heat and will bend like melted rubber when exposed to high temperatures. Osage orange wood is also relatively expensive and challenging to find.

Bamboo

Bamboo is another option that offers longevity and heat resistance. Heat increases its elasticity, resulting in more force being transferred to the arrow. When using bamboo, it is recommended to let the outer surface be the belly to improve balance.

Red Oak

Red oak is readily available at most hardware stores and home improvement retailers. When selecting red oak, ensure you choose a piece with thick late growth rings, as it is a porous wood. Red oak is heavier, and like other woods, it needs to be backed for good support.

Ipe

Ipe is a strong wood that allows for thinner limbs, making the bow lighter overall. Many archers use ipe and back it with bamboo. Ipe is also known for its high resistance to decay. However, it is important to note that some people may be allergic to this type of wood.

Eastern Redcedar

Eastern redcedar, or Juniperous Virginiana, is a type of juniper. It is lightweight and brittle, making it suitable for recurve bows. It has strong compression but weak tension. One challenge with eastern redcedar is that it can be difficult to obtain.

Dogwood

Dogwood is commonly used for bows in Europe. It is dense, strong, and has high compression. When selecting dogwood, ensure it is free of knots, as they do not bend well and can cause the wood to crack.

When choosing wood for your recurve bow, consider factors such as strength, flexibility, availability, and cost. Remember that the wood should be able to bend without breaking, providing the necessary snap for the bow's performance.

Shaping the bow

Marking and Cutting:

Start by marking the design of the bow on your wooden stave. This includes the handle, riser, and limbs. When marking the limbs, draw them flat and straight as they will be bent later. The handle should be in the middle, about 8 inches long. Also, mark where you want the bowstring notches to be.

Next, use tools like a hatchet, bandsaw, or jigsaw to cut out the shape of the bow. Ensure you retain the desired length. The handle should be about 1.5 inches thick.

Identifying Belly and Back:

You need to identify the belly and back of the bow stave to understand how to bend it. The back is the outer surface facing your target when shooting, and the belly is the inward curve facing you.

Testing Flexibility:

Stand the stave upright, with the tip of the lower limb on the ground. Gently bend the bow to test the wood's flexibility.

Trimming and Shaping Limbs:

Clamp the bow in a vice around the handle area. Use tools like a drawknife, files, sandpaper, or a plane to trim and shape the limbs to your desired thickness. Remember, the thickness determines the draw weight. Aim for a slightly heavier draw weight, about 5/8 of an inch thick, and always shave away from the belly, not the back.

Bending the Limbs:

The limbs on a recurve bow curve away from the handle and then back towards the tip. Use a bow shaping frame to secure and bend the bow into shape. Tie the stave and use screw clamps to secure it. Ensure precise measurements so both limbs are bent at the same angles. Leave the bow fixed overnight to settle into position.

Creating Notches:

Use a cylindrical file to carve notches towards the tip of each limb. Work on the inside wood to preserve strength.

Tillering the Bow:

Tillering refers to achieving an even bend in the bow when pulled back to full draw. Attach a long piece of parachute cord or nylon string, double the length of your desired bowstring, to the notches. Secure the bow handle to a clamp at the top of the tillering stick. Pull the tillering string down to one of the notches, gradually improving flexibility and checking for even bending. If the bow bends unevenly, remove it and shave down the limbs.

Repeat this process, moving the tillering string to higher notches, until you reach your ideal draw length. This may take months of adjustment. If the bow creaks, remove it and adjust the limb thickness.

Once complete, smooth the wood, especially around the handle, with sandpaper for a comfortable grip. You can then stain or varnish the bow for protection.

Bending the limbs

The limbs on a recurve bow curl away from the handle initially and then curve back out towards the tip of the limbs. To achieve this, you'll need to use a bow shaping frame. This will allow you to secure your bow using clamps while gradually bending it into shape.

Make sure to use precise measurements—both limbs should be bent at exactly the same angle to create an efficient bow. With the handle fixed in place, bend both limbs at the exact same point on either side.

Once you've finished bending the bow, leave it fixed and tied in the shaping frame overnight. This allows the wood to settle into the desired position.

Now it's time to sort out the bowstring. Use a cylindrical file to carve out the notches at the desired place towards the tip of each limb. Work on the inside wood, not the outside, to preserve strength.

The bow must now be tillered. Tillering refers to how evenly the bow bends while being pulled back to full draw. Attach a long piece of parachute cord to the notches of the bow. This cord needs to be double the size of the bowstring that you want to use.

Secure the handle of the bow to the clamp at the top of the tillering stick. Pull the tillering string down to one of the notches on the tillering stick. This allows you to improve the flexibility of the bow while also checking that it bends evenly.

If the bow is bending unevenly, remove it and gradually shave down the limbs a little more. Once the bow is flexible enough to bend at the first tillering notch without feeling too stiff, set the tillering string at a higher notch and let the bow sit. Repeat this process until the bow is at your ideal draw length. This may take months of gradual adjustment.

If the bow starts to creak at any point, remove it. This is a sign of strain. Adjust the thickness of the limbs and try again.

Stringing the bow

Now that you've shaped the bow to your liking, it's time to string it.

Cutting the Notches

First, you'll need to cut notches at the top and bottom of the limbs. These notches will hold the bowstring in place. It's best to use a long, cylindrical file for this, but a knife and a flat, narrow file will also work. Remember to cut the notches on the inside of the bow to protect the integrity of the outside wood.

Attaching the Tillering String

Next, you'll need to attach a tillering string. This is what gives your bow its draw. The tillering string should be about twice as long as your intended bowstring. Tie a loop at each end of the string and attach it to the notches on the limbs. Parachute cord works well for this.

Adjusting the Tillering String

Place the bow on a tillering stick and pull the tillering string to one of the notches closer to the top of the stick. Pull the bow further, taking note of how it bends. The tillering process takes time and should be done gradually. If you hear noise coming from the bow, stop and use a large file to shape the limbs some more. This process can take months, but it will allow you to increase the draw of the bow to a good length.

Attaching the Bowstring

Once the bow has reached an acceptable draw, remove it from the tillering stick and take off the tillering string. Now, attach your bowstring. Loop both ends of the string around the notches. Nylon is a very popular choice for bowstrings.

Testing and Adjusting

The bow can be strung and fired during the tillering process, but it may not be at full strength, and firing might hinder the success of the tillering process. Once the tillering process is complete, you can add artwork, leather, or a protective coating to your bow.

Finishing touches

Once you have completed the tillering process, you can add artwork, leather, or a protective coating to your bow. You can also stain the bow or add a protective layer such as varnish to guard against moisture or other problems. Smooth the wood, especially around the handle, with sandpaper to prevent rough bits and splinters.

If you are using surgical tubing, you will need to make a string. Grab some nylon string and tie a basic knot at one end, then cut it down to a short length. Repeat this process two more times. Take the short knotted lengths of nylon string and place them in the holes of the sling bow, knot side up. Measure out around a 23 cm length of surgical tubing and cut it down to size as needed. Repeat this process to make a second length of tubing.

Next, tie the other end of the nylon string lengths with another basic knot. Then take your lengths of surgical tubing and insert them over the exposed knots of the nylon string. Take some cable ties and firmly secure the surgical tubing just above the nylon string knots. Make sure they are as tight as you can make them.

Take your last length of nylon string and tie knots in both ends. Then, connect the two lengths of surgical tubing with the nylon string and secure them using more cable ties. Snip off any excess cable-tie lengths.

Finally, you can add a pull release. Take a long length of nylon string, loop it, and tie the ends on either side of the nocking point of the sling bow’s string. Then, tie the main length of the loop into another knot so that you can easily hold and draw the string. Your sling bow is now ready to go!

Frequently asked questions