All Terrain Cedar Saw
Colby Funk, Wendy Sheets, William Thomason
All Terrain Cedar Saw LLC is a small business owned by Ron Cole. The undercarriage, or portion that mounts under the all terrain vehicle, is built by Cole in his shop located near Vici, OK. The main frame for the cedar saw is built by a company in Oklahoma City. The cedar saws are packaged for shipping in his shop, to be assembled on site. They are shipped in two pieces: the large sub frame and another large box containing the remaining components and parts, with the exception of the cable winch. The All Terrain Cedar Saw is currently designed to cut cedar trees at ground level no larger than 5 inches in diameter. It attaches at the front and rear of a 500 cc or larger ATV. A winch at the front and a 2 inch receiver hitch welded to the rear of the ATV are used to carry the cedar saw. A 9 horsepower Briggs & Stratton engine is used to power the 14 inch diameter 60 tooth saw blade via a v-belt. The blade is engaged by an electric clutch via a footswitch.
A significant problem associated with the current design of the All Terrain Cedar Saw is the design’s failure to evenly distribute the weight of the sawing apparatus. Most of the weight of the All Terrain Cedar Saw is carried by the front of the ATV since all the major components are suspended from the front. Safety is a major concern as well. When the footswitch is disengaged the blade does not stop turning immediately, but rather takes a few seconds. Besides the problems of weight and safety, several other issues arise with the current design of the cedar saw. One is the freedom of motion at the front end of the apparatus. The blade is allowed approximately 20 degrees of swing in the horizontal plane, which may add to problems in safety. Another operational issue is the need to slow down and lean forward on the ATV to bring the saw blade close enough to the ground to cut the cedar tree below the lowest limb. Also, welding a receiver hitch to the rear of the ATV may void some warranties. Thus, the goals of the project are to: investigate weight reduction concepts, improve the stopping time of the blade, control the horizontal swing of the frame, investigate safety concepts concerning blade exposure, address the operational technique, and investigate actual power requirements.
Scope of Work
Ron Cole has identified several limitations of the All Terrain Cedar Saw. The cedar tree must not exceed 7 feet in height and a trunk larger than 5 inches in diameter. The cedar saw is only designed for use with small soft wood trees in pasture lands. Continuous use of the winch to adjust the height of the blade is not recommended. Adjusting the blade height is necessary when operating in rock-covered areas, rough terrain, or loading and unloading the ATV. When the footswitch is frequently pressed and released, the clutch will overheat. Due to the weight of the cedar saw, the handling characteristics of the ATV will change. Thus, the ATV must be operated at reasonable speeds. RangeScaping will focus on several goals in making design improvements to the All Terrain Cedar Saw. First, we will explore different options of correcting the weight distribution. Placement of the engine, size of the engine, and using counterbalance weights are possibilities. Second, safety issues will be addressed. Rigidly attaching the cedar saw to the ATV, and using a brake clutch to stop the blade immediately when the footswitch is released will increase the safety features.