rESULTS
Movement Test
Axial Force
Movement
Weight Test
Dimension Test
Lead Screw Drive Train
Duty Cycle
Pruner Requirements
Failed
Passed
Passed
Passed
Capable of cutting a 1.75 inch tree branch.
Cutting blade must be at least 30” away from trigger.
Must weigh less than 3 lbs.
All components combined must cost less $500.
Drive Train Requirements
Passed
Passed
Failed
Passed
Passed
Passed
Passed
Passed
​
The blade must re-open unassisted by the user.
Must attach to a standard drill clamp.
All parts must withstand 440 in-lbs. of torque and 1000 lbs. of linear force without deflecting more than 0.25”.
Drive train must convert rotational motion to linear motion.
Must connect the motor to the blade.
Must completely open and close the blade.
Must fit within a 1” diameter housing tube.
Drive train itself must weigh less than 1.25 pounds.
Working Design Change
Pruner Requirements
Passed
Passed
Passed
Passed
Capable of cutting a 1.75 inch tree branch.
Cutting blade must be at least 30” away from trigger.
Must weigh less than 3 lbs.
All components combined must cost less $500.
Drive Train Requirements
Failed
Passed
Passed
Passed
Passed
Passed
Passed
Passed
​
The blade must re-open unassisted by the user.
Must attach to a standard drill clamp.
All parts must withstand 440 in-lbs. of torque and 1000 lbs. of linear force without deflecting more than 0.25”.
Drive train must convert rotational motion to linear motion.
Must connect the motor to the blade.
Must completely open and close the blade.
Must fit within a 1” diameter housing tube.
Drive train itself must weigh less than 1.25 pounds.
With the Self- Reversing Ball Screw lacking the ability to withstand any sort of axial force, a design change was initiated in order to produce a working product. A small lead screw welded to a drill bit adapter and bolted to the rest of the drive train was able to get the pruner up and running but failing to achieve the requirement of returning the blade unassisted. Concentricity and denominational issues were a few of the major obsticles with this design change.