Group 20 - Product Name Here/Gate 2
We are still working diligently on our project and part of our initial plan has worked very well and other parts have not gone as planned. We have followed our plan to meet every Monday after class in the Capen café. This part of the plan has worked very well due to everyone’s schedule allowing this time to work. This is the time when we can all meet as a group without missing anyone. In our work proposal from gate one we stated “To disassemble, the team will collectively meet twice a week in the lab. We will make every effort to all attend so that information and knowledge are not lost in communication.” There have been some problems with this part of our initial proposal, every member of our group has a very busy schedule and we are all doing our best to coordinate meeting times but there have been meetings were all members could not be present. We have also not been able to meet the said two days a week in the lab. We have found that we had all of the tools necessary to disassemble our product outside of the lab, so we did not follow the plan exactly. Also we did not follow the plan to bag and catalog all of the parts during the disassembling process. Due to the time that we have had to work together we were able to disassemble our product, indentify the pieces, photograph the process and also reassembly our product, so there was no need to bag and tag the pieces.
We have addressed the issue of not being able to meet all together by taking many pictures and going over the dissection process with whoever could not be at the meeting. For the same issue that may occur in the future we have been considering and will be discussing setting up a different meeting time on top of our Monday meeting so that we would have at least two meetings every week that everyone would be able to attend.
In order to quantify the difficulty of each step, several factors must be taken into consideration. The difficulty of each step can be broken down into the physical difficulty, complexity and time required for each.
The physical difficulty can be described as the dexterity required to complete the step. It also includes the skill required to remove the part without causing damage to it.
- Little to no dexterity required
- No tools required
- Some degree of dexterity required
- Some risk of damage to parts
- Possible use of tool required
- High level of dexterity required
- Medium to high level of risk of damage
- 1 or more tools required
The complexity of the step can be described as how difficult it would be to re-create the orientation of the parts.
- 1-2 parts
- Simple orientation of parts
- 3-5 parts
- 6+ parts
The time of each step can be described as:
- 1-10 seconds
- 11-60 seconds
- 60+ seconds
|Step||Description||Part||Tools Required||Level of Difficulty||Image||Extra Images|
|1||Turning the actuator and gear assembly unscrewed the locking screw, which released the blade support and shoe assembly.||Locking screw and shoe assembly||No tools needed||None|
|2||The removal of all 7 screws holding the plastic housing together.
This part was meant to be taken apart. Screws are a non-permanent method of attachment and the heads were Phillips.
|Screws||Phillips head screwdriver||None
|3||Removal of the plastic housing||Plastic outer housing||No tools needed||None|
|4||Removal of the actuator/gear assembly and the blade guard
These parts were not attached to the drill and were likely intended to be removed at some point for cleaning, maintenance, etc.
|Actuator/gear assembly, Blade guard||No tools|
|5||We then removed the shaft assembly||Shaft assembly||No tools needed|
|6||We took out the rest of the assembly out of the housing||Everything else that was in the housing, everything was connected||No tools needed||None|
|7||Removal of the gear assembly that rotates the shaft assembly||Gear assembly||No tools needed|
|8||Removal of the counterweight||Counterweight||No tools needed|
|9||Removal of the thrust plate||Thrust plate||No tools needed||None|
|10||We removed the armature assembly from the field assembly||Armature and Field assembly||No tools needed|
|11||We then removed the Brush boxes||Brush boxes||No tools needed|
|12||We removed the switch assembly from the trigger assembly||Switch assembly/Trigger assembly||No tools needed||None|
|13||Removal of the trigger conductor||Trigger conductor||No tools needed||None
|14||We pried open the switch box to take out the chip and look inside the switch assembly||Switch Box||Flat head screwdriver and razor blade|
Sub System Analysis
The process of removing the material is broken down into a few subsystems. When the user pulls the trigger the saw detects that, measures the pressure on the switch, and produces the right amount of energy. That electrical energy is then converted to rotational mechanical energy. Then that converts to translational mechanical energy.
All subsystems are connected linearly except the air flow that cools the motor and the final energy input to push the saw in a given direction. The electricity enters through the cord and is connected to the trigger. Once the trigger is pulled the electricity travels down to the motor. The motor turns a fan consisting of many blades that pulls air through the back of the jigsaw (below the cord). In doing so, the air travels across the motor, cooling it. The air is then pushed down to the jigsaw’s blade area where we assume it is used to blow sawdust away. The excess air is discharged though the sides. The motor also turns the gear assembly. The gear assembly is directly connected to the shaft assembly; this connection is the transition from rotational to translational motion. This translational motion combined with the input of human energy to guide the saw finishes the process and removes the material.
The components are placed in a line toward the blade holder. They are positioned that way so the parts take up as little space as possible. The safety guard and blade can not touch each other. The better the connection between the subsystems, the better the jigsaw performs. That way the energy lost can be minimized.
Depending on what country you are in, you might need a different plug. The jigsaw is relatively cheap so economic concerns are minimal as are environmental. The handle design is ergonomic and the guard helps with safety.