SMALL FARM SUBSOILER midterm presentation USDA SPONSERED SENIOR DESIGN PROJECT Jason Lueck Matt Maples John McBride Brad Mooney Manuel Pagan DESIGN REQUIREMENTS Scaled to work on a small farm Low cost to purchase under 3000 Able to penetrate at least 10 15 preferred Modify an existing tiller Troy Bilt Horse Surface soil left undisturbed EXISTING SOLUTIONS Standard walk behind tiller Ditch Witch trenchers Ditch Witch vibrating shank Mid sized riding and walk behind tractors PROBLEMS WITH EXISTING SOLUTIONS Tillers Disturb top soil by tine rotary action Limited depth typically under 10 PROBLEMS CONT Ditch Witch Trenchers Vibrating Shank Excessive cost 6500 for trencher 8000 for vibrating shank PROBLEMS CONT Mid sized tractors walk behind tractors High cost typically several thousand dollars Too large for the smallest farms POSSIBLE SOLUTIONS Straight shank Rotary chisel Trencher STRAIGHT SHANK For this design a straight shank would be attached behind the tiller frame SHANK ADVANTAGES This design can be easily attached to the existing tiller frame The ease of attachment allows for easier modification for the consumers who already own a Troy Bilt There are readily available mounting brackets that could be easily modified to fit the tiller frame This would lead to less new design work SHANK ADVANTAGES CONT The decrease in design work and ready availability of parts will greatly lower cost The lack of moving parts will decrease maintenance making it more appealing for the customer The straight shank design is currently used on a larger scale so the design is already proven SHANK ADVANTAGES CONT The shank can be easily adjusted allowing the operator to move the tiller between storage and the field easy The depth of operation can be easily adjusted allowing for higher speeds at shallower depths SHANK DISADVANTAGES Larger Shank HP Requirements 20 18 16 14 Horsepower depths require large horsepower increases leading to much higher costs or much slower speeds To achieve the desired depth the forward speed will be relatively low 0 7 mph 14 depth 12 10 8 6 4 2 0 5 6 7 8 9 10 11 12 Depth in 5mph 7mph 1 2mph 1 7mph 13 14 15 SHANK DISADVANTAGES CONT The traction of the tiller tires will limit the amount of HP that can actually be used ROTARY CHISEL A rotary blade would be attached to the PTO of the tiller CHISEL ADVANTAGES There is roughly a 40 horsepower savings for a rotary shank over a straight shank allowing for greater forward speed and greater depth of digging Rotary Chisel HP Requirements 12 10 Horsepower 8 6 4 2 0 5 6 7 8 9 10 11 12 Depth in 5mph 7mph 1 2mph 1 7mph 13 14 15 CHISEL ADVANTAGES CONT The forward chisel rotation causes the tiller to drag itself forward allowing for easier use by the operator Can cut through underground obstructions easier than the shank CHISEL DISADVANTAGES To penetrate 15 would require a blade diameter of 36 leading to some major safety concerns At minimum a strong guard would have to be built around the blades since there will always be several inches of spinning blades above ground The handles would have to be moved also CHISEL DISADVANTAGES CONT No existing design would require that all of the parts be designed and built from scratch greatly increasing cost The clutch would have to be redesigned to allow for reverse to become forward Since the drive shaft is off center the tiller will try to drag itself off of a straight line Several moving parts will increase maintenance and decrease durability TRENCHER A chain type trench digger blade would be attached to the PTO of the tiller frame TRENCHER ADVANTAGES The rotary action of the chain allows for lower horsepower requirements than straight shank comparable to the rotary chisel The chain design allows for nearly the entire cutting blade to be below ground during operation making for safer usage than the rotary chisel TRENCHER ADVANTAGES CONT Can cut through underground obstructions much easier than the shank or chisel designs Lower cutting horsepower requirements allow for higher forward speeds TRENCHER DISADVANTAGES There are more moving parts which will lead to lower durability and higher maintenance The chain guide will be very heavy making adjusting the depth and pulling the arm up for transport very difficult Having the trenching arm in an upright position will make it hard to transport TRENCHER DISADVANTAGES CONT The parts that are currently available for purchase are very expensive chains start around 500 The trencher works by removing the dirt so it would have to be replaced in the trench CONCLUSIONS There are three main design types which could be used to create a subsoiler to meet our design criteria We feel that the shank design will be the best design DESIGN COMPARISONS Shank Chisel Trencher Cost Least Expensive Expensive Most Expensive Ease of Design Least Design Most Design Work Work Some Design Work Safety Very Safe Safe Least Safe DESIGN COMPARISON CONT Shank Maintenance Low Maint Chisel Trencher Mid range Maint Most Maint Reliability Most reliable Reliable Least Reliable Efficiency Least Efficient Comparable Comparable