1 - 10ft length of 3/4'' PVC Pipe ($1.60)
4 - 3/4'' Elbow Connections ($1.30)
4 - 3/4'' Tee Connections ($1.30)
3 - 45 Yard Rolls of Industrial Grade Duct Tape ($18.00)
1 - Can of PVC Pipe Cement ($2.00)
1 - 2" Buckle ($2.50)
Spray-paint for the frame
Buckles for bag openings
Foam padding for the waist and shoulder straps (The stuff I used was not high-grade, it still works great)
Very basic PVC bending skills.
Step 1: Cutting and Bending the Pipe
2 x 19cm - lower sides of frame
2 x 24cm - upper sides of frame
6 x 36cm - middle sides of frame and cross pieces of frame
It's not as important to use these exact lengths as it is to make sure the pairs are exactly the same. Otherwise the frame will be lopsided, and feel funny on your back.
Now take four of the six 36cm lengths, and bend them to your desired angle. I bent mine with a 5 gallon bucket, but you can use whatever round object you may have.
eHow had a great explanation of how to bend PVC, so I'll include the link to their instructions. http://www.ehow.com/how_4796089_bend-pvc-pipe.html
My bent lengths are now about 33cm on a straight line from end to end.
Step 2: Fitting and Assembly
If you want to spray paint the frame, do it now.
Step 3: Cutting Out the Bag
Make the sides of the bag separately, and then match up the sides to ensure they are the same size.
Here are my dimensions if you would like to use them:
(Notice that there are only four pieces, I have two sides, the bottom, and the front. The back is going to be against the backpack frame, and the top we will do later)
Sides - 52cm Tall x 28cm Deep
Bottom - 37cm Wide x 28cm Deep
Front - 52cm Tall x 37cm Wide
Step 4: Assembling the Bag
Here's what the bag will look like. (The frame is just in the picture to hold up the bag for the picture. This is not what the bag will look like sitting on the frame).
Step 5: Attaching the Bag to the Frame
Now start taping the top section of the bag onto the frame down to the upper cross piece. I took strips across the width of the frame because I want support bands across the top section. If you don't want these, feel free to just tape down the bag on each side.
Make sure to cover the sticky backside of these strips of tape.
Step 6: Trimming
Step 7: Closing Up the Back of the Bag
Don't tape over the side bars until after step 8.
Step 8: Back Support
Step 9: Shoulder Pads and Straps
Cut out two strips(42cm x 8cm) of foam. Make 4 strips of duct tape the same size. Layer each piece of foam between two strips of duct tape. Duct tape around the edges.
**You can also taper the ends of the foam to make it fit your body better. This is an improvement I wish I had done...but it is not necessary**
The rest of the shoulder strap (the skinny part) can be made next. I folded a strip of duct tape in half, and taped on two more layers to make it thicker.
**There are a couple ways to attach the shoulder straps. I chose to use plastic sliders so that the straps would be easily adjustable. You could also probably make some sort of duct tape slider, or simply tie the straps down. **
Attach a buckle like the one pictured to each of the padded should straps by running a narrow strip of duct tape through the top loop. Then tape that strip to the bottom of the should strap.
Make 2 duct tape pieces 35cm x 2.5cm. Run these skinny straps through the bottom of the buckle.
Attach the shoulders straps to the upper cross bar. You can put them as close or far from the sides as you want, whatever is comfortable.
Attach the skinny straps to the sides of the frame or the lower cross bar, whichever is more comfortable.
Step 10: Waist Strap
Begin by cutting out some padding(If you want it) and taping over it the same way you did with the shoulder straps. Here are my measurements:
You may have to make this waist strap shorter or longer depending on your waist size. Strap should be snug enough that it sits on top of your hips, so they can bear the weight of the backpack.
Before you attach and tape down the waist strap, add some kind of connective device to the ends of the strap. This is where I used the 2 inch buckle, but there are many different options.
If not the buckle, I would recommend a two ring setup, where there are two rings attached to one end of the strap, and a length of tape on the other that can be wound through these two rings. This setup is easily adjustable, which is important for the waist strap.
No matter what setup you use for the waist strap connector, make sure it is adjustable.
Now simply tape down the waist strap to the frame (at the bottom two crossbars) so it is well-secured.
Step 11: Bag Flap
This is going to be the flap over the top of the bag. Cut out two corners (about 1 inch square) so the flap will fit between the sides of the frame. Tape this down to the top of the bag.
You can use buckles to secure the flap down, but I'm content with a strip of duct tape. Both will work just fine.
Step 12: Bag Support (Optional)
After completing the backpack, I realized that the bag was a little too flimsy, so I added a support in the bottom.
A wire hanger does the trick quite well, just bend it into the shape of the bottom of the bag. Place it in the bottom of the bag and tape it down.
Step 13: Accessories
Remember to throw in a roll of duct tape when you go hiking for any repairs or additions you need to make.
Step 14: CELEBRATE!