Since I started my dog in agility classes, I've been building a series of course obstacles. Some of these obstacles are quite expensive to purchase in high quality, new condition. My purpose has been to make serviceable ones at home with minimal cost. A tire jump basically consists of a hoop of 4" corrugated drain pipe. This "tire" is suspended from a frame in such a way that its height can be adjusted for dogs of varying size. After scouring the interwebs for designs, I decided to make the tire jump from a pallet, which would comprise a ready-made frame, avoiding the time, tedium and expense of building one from scratch out of PVC pipe or wood.
Plastic 4" corrugated drain pipe, 100 inches.
Joint adapter for 4" drain pipe
Six 1 /7/8" screw eyes
Nylon 550 cord (paracord), 6 feet
Two 30" bungee cords
Deck screws, various sizes
Two split rings, 1" diameter
Electric screw driver
Step 1: Prepare Drain Pipe "tire"
Surprisingly, the standard tire jump does not use an actual tire. For the early training of my standard schnauzer Isabel I used a hand-held hula hoop, but the day came when I needed a more realistic apparatus. To make a regulation-sized hoop for the tire jump, I needed 98 inches of drain pipe. I had enough left over after using a 100-foot roll to outfit the downspouts on two houses. In the process, I learned that this stuff is thin-walled and somewhat fragile. It would be very difficult to cut it perfectly all the way around. Hence, I cut it roughly four inches too long, then used scissors to carefully cut it down to the ideal size.
Odds are the pipe will have some curvature to it, but the hoop needed is much more tightly curved. I increased the curvature of the pipe and made it the right shape by forcibly bending it around my knees repeatedly along its length. Finally, I bought an adapter to join the two ends together. This piece is very inexpensive, and is normally used to join together two ends which simply snap into it.
Step 2: Strip the Pallet
First, I started with an oversized pallet, 44" x 56". I think this one was used to ship a heat pump that was installed at my workplace. I scavenged it before it was thrown in the dumpster. It had to be an extra long pallet in order to provide adequate jump height.
I removed all the 1 x 8" boards from the pallet except the outer two. I used a hammer and pry bar. If you are slow and careful, you might leave the remaining boards in a nice smooth condition. I wasn't slow and careful, and only one of the boards I removed survived (to be seen later). A handy removal technique is described here.
A pair of two-by-fours remained in the middle of my frame-to-be, and I had to remove them from the more fragile one-by-eights. After some cogitation, I cut them across the center with a reciprocating saw. I laid the pallet down on the driveway, put my feet on the one-by-eight and grabbed the two-by-four by its freshly cut end, pulling up so that it served as its own lever. This method worked masterfully the first time, as the nails were pulled out of it without difficulty. On the second attempt, the one-by-eight cracked a bit. The crack wasn't severe, so I continued. I switched to knocking the two-by-four from side to side with a crow bar to make some space between the boards, then using the same crow bar to pry the two-by-four off. Finally, I had the basic frame that I would use for the tire jump.
Step 3: Stabilize, Top, and Add Feet to the Frame
After reducing the pallet to a simple square, it had become somewhat wibbly-wobbly. I made sure the corners were square, then drove a pair of two-inch deck screws into each corner, predrilling to prevent splitting. It's structural rigidity considerably improved, I used the one remaining one-by-eight that hadn't split from the previous step to cap the top of the frame, providing a member by which to hang the tire. As it was already the proper length, I simply fit the board to the top of the frame, predrilled holes and drove a pair of 2" deck screws into each end.
To make the feet of the frame I had planned to use a two-by-four from this pallet (removed in the last step), but they were pretty ranked out, so I grabbed one I had left from a different pallet. The board was 44 inches long. I marked it in the center, then marked it 4" away from center on opposite sides and marked a diagonal line between these last two points. I made a line with the same slope at each end of the board to create the pattern for the two feet. I marked the feet in the center and the two-by-fours at the bottom of the frame at their centers, matched them up, predrilled holes, and drove in three 3 1/2" deck screws to attach the feet to the frame. Now it stands on its own two feet!
Before attaching any hardware, it was a good time to prep the surface. Wearing heavy leather gloves I broke off all the larger splinters. Then, using a random orbit sander with heavy grit paper I sanded all the rough parts. A couple of coats of paint added later will help to smooth it out further.
Step 4: Attach Tire to Frame
So far the project had cost almost nothing, but I splurged on a real pulley and some screw eyes. I put one screw eye in my vise and bent it open with a massive pair of pliers, placed the swivel eye of the pulley in it and bent it shut again. I marked a line in the center of the top board and a point on the line 2 1/4" from the back so that the tire would not bump the boards when moving it up and down. I drilled a hole at this point and turned the screw eye with the pulley into it.
I stabilized the tire so that it moves up and down without twisting from side to side by using bungee cords to guide the left and right sides of the tire. I marked the inner surfaces of the side boards of the frame 6" from each end, predrilled holes and turned a screw eye into each. I attached the end hooks of the bungees to the screw eyes. I tied a 1"-diameter split ring to each side of the tire with 550 cord and passed a bungee through each. I used 30" bungee cords stretched to 44 inches to maintain the right tension.
I attached one end of a 4-foot length of 550 cord to the convenient groove in the center of the joint adapter via a clinch knot. I ran the other end of the cord through the pulley and through the upper left screw eye holding a bungee end. I tied a loop in the end of this cord, measured the height of the tire needed for my dog (16 inches), lifted the tire to that height, then turned a screw hook into the side of the frame at the point of the loop in the cord. I lowered the tire to another practice height, marked it and set a screw hook at that point (higher on the frame) as well.
Step 5: Finishing Touches
I added stripes of colored electrical tape to the tire to enhance its visibility. I'm not sure how necessary this step is to the dog, but it is standard practice. Once the weather warms up I will be painting the wood using exterior house paint, only because I'll be using the jump primarily outdoors.
My parting thought is that I saw the potential for the frame of the tire jump in the pallet. I'm sure many more things could be made from pallets at considerable savings of time and energy if we could see the possibilities.