Designers: Charles Chen, Billy Chyan, Zach Tay, Jarey Wang
Supervising Professor: Larry Bohs
https://www.youtube.com/watch?v=cJOmQ1pLr0w
INTRODUCTION
Figure 1. Kayak Transporter
Our client is a competitive kayaker with spina bifida. She desires to independently transport her kayak from the car to the dock so that she can train for the Paralympics. The Kayak Transporter consists of a modified wheelchair, a front attachment, a rear attachment, and a combing lasso. The kayak is placed on the rear attachment and slips into the front attachment. The front attachment connects to the modified wheelchair using a rotating hitch, allowing the client to tow the kayak behind her. A tow rope and reel allow the kayak to be pulled up steep slopes without being attached to the wheelchair. Using the Kayak Transporter, the client can transport her kayak from her car to the water and back independently.
SUMMARY OF IMPACT
Our client is an avid kayaker training for the US Paralympics team. While she has an accessible car rack for her kayak, she previously required assistance at the lake to move the kayak to the water and back. The kayak transporter allows her to do these operations by herself, making it far easier to schedule consistent workouts. She commented, “I am so pleased with the end product! I am inspired to keep parakayaking in spite of all the challenges that my body seems to give me. Being able to get on the water before the sun comes over the tree line will be huge for training.”
TECHNICAL DESCRIPTION
The kayak transporter consists of four components: a modified wheelchair, a front attachment, a rear attachment, and a combing lasso.
The modified wheelchair is equipped with two 25’x2’’ knobby tires, allowing far better traction on loose, muddy and uneven terrian compared to the original street tires. Two 6” pneumatic front casters provide similar advantages over the original narrow casters. A custom hitch includes a clamp and pin. The clamp is made from a block of aluminum, drilled to accommodate the rear handle of the wheelchair and then cut in half. Four ¼-20 bolts secure the clamp to the handle. The pin is a ½’’ threaded steel bolt that screws into the bracket, beveled to a round tip to facilitate attachment of the hitch arm, described below.
The front attachment interfaces with the modified wheelchair via a hitch arm, a 12’’ long x 1’’ square aluminum rod with a 0.6’’ diameter hole for the hitch pin. The frame of the front attachment is constructed using 1’’ square aluminum rods. A nose shealth integral with the frame is comprised of two ¾’’ diameter, custom-bent aluminum pipes. Both the front attachment frame and the nose shealth are padded using foam insulation to prevent damage to the fragile kayak body. A 5’’ platform caster wheel bolts onto the bottom of the front attachment frame. This wheel raises off the ground when the front attachment hitches to the wheelchair, but allows mobility of the kayak when not attached to the wheelchair.
The rear attachment is composed of a rear cradle, a rear attachment frame and wheels. The rear cradle is made from two separate ¾’’ diameter pieces of custom-bent aluminum pipe. The frame is constructed using 1’’ square aluminum rods. A 1/16’’ thick, ¾’’ wide L-bracket cross-bolts onto the rear attachment frame and is combined with a rubber end cap to form a brake stand . This stand holds the rear attachment steady while the kayak rear is loaded. The rear attachment wheels comprise 26’’ knobby mountain bike tires on aluminum frames. The wheel hub axles are modified using sealed ball bearings, press fit into custom bronze sleeve, allowing them to interface with holes in the rear attachment using ½” quick-release pins. This allows the client to quickly and easily attach and detach the rear wheels from the rear attachment for storage in her car.
The combing lasso, composed of ½’’ nylon straps and corresponding buckles, secures the front attachment, the kayak, and the rear attachment to each other. During testing, the client had difficulty pulling the transporter up the steep, muddy hill from the dock. A rope with buckle is provided to attach to either end of the transporter, so the client can pull the kayak up the hill after climbing the hill with her wheelchair only. A metal reel allows the rope to be stored without getting tangled.
Figure 2 shows the client using the Kayak Transporter. Replacement cost for the device is about $400.
Figure 2. Client using the Kayak Transporter to move her kayak to the lake.