1.1.6 compound machine project report
Maverick Murphy
Daniel Afshar, Nathan Mara, Ryan Sze
POE 2
9/25/15
Project 1.1.6 Compound Machine Design
Design Problem: For this project, we are to design a compound machine that must lift a weight of approximately 8 ounces a vertical distance of 6 inches in less than 3 minutes.
The learning objectives was to understand how elements of design can affect mechanical advantage, understand how simple machines can work together to accomplish a task, compare the efficiency of different simple machines in a working situation, experience the capabilities and limitations of VEXⓇ components for future projects.
The criteria and constraints are: The applied effort force may
only be provided by a single human input. The final design must include a minimum of three different types of mechanisms. We MUST include any two of simple machines. The third mechanism can be any of the following: a gear system; a pulley and belt system; or a sprocket and chain system. Each required mechanism must have a mechanical advantage greater than 1. Final design must have a mechanical advantage greater than 1.
Brainstorm Idea:
For my idea, pull on a string that goes to a pulley, which leads to another pulley, then to one end of the lever. The lever moves down pulling on the string attached to another pulley, finally pulling up the load.
Final Design Proposal: We chose Daniel’s design because it scored the best on our design matrix. It is simple, and works. Our categories for the design matrix were: simplicity, time, trustability, resilience, and cleanliness.
We had simplicity because the most important thing was that it would work and we all understood it. Simplicity and time indirectly went together when we were deciding what design to use. We had a small time frame and did not want to have to rush everything because it would take so long to assemble the product.
We wanted to be able to trust that the product would work and we would not have to change everything we had on it to get it to operate correctly. We chose resilience as a category because having the product break on us would not be an ideal circumstance. Cleanliness was very important because having a mess to clean up afterwards would take up a lot of time that we could have to get measurements.
After our discussion and debate Daniel’s ranked the highest making it the winning design. In Daniel’s design we turn the gear on the right side, which turns a chain, turning another gear and a wheel and axle. From there a string wraps around a wheel then goes through a pulley. The string from there goes to the first class lever, pulling up on a string with a rope attached to it.
Design Modification:
We also added a sprocket to the center of the chain system to help it flow better with less slack and to have less rub. Adding the sprocket helped it very much and it worked better.Before it had a lot of friction and slack, after it had little friction and little to no slack.
We flipped the pulley upside down and secured it to the frame so it will be more secure and won’t wobble as much. This helped the system work for efficiently and it would wobble less. Before, the pulley barely worked, after the pulley worked very well.
We had to adjust where we start the rope on the wheel and axle so it will wrap the correct way. When we spun the wheel that the rope wrapped around it would fall down onto the axle which would tangle it, and it would decrease the mechanical advantage and would make it take a lot longer to lift the load. Wrapping it from the side closer to the frame fixed the problem the majority of the time.
We originally planned on having the load attached to a single string then on the the lever. It was difficult to attach our load to one string because our load was in the shape of a cylinder. We made a complex holster for the load that composed of 2 strings., and cradled the load. The holster held up and worked very well for what we needed it to do.
We made the lever longer so that we could have a greater mechanical advantage and it would be able to pull the load up 6 inches. To extend it we put 2 components of the vex kit together. Extending the load made it easier to lift the load the target distance with less effort force.
Final Design Proposal:
In the final product we still turned the wheel on the very right side. That wheel had a sprocket on the same axle that turned the chain. The chain turned the other sprocket, which had the other wheel on the same axle. The wheel turned and the rope wrapped around it. The rope went through the pulley to the lever. The lever then pulled the load up more than 6 inches.
During the presentation the machine operated as it was supposed to. The machine lifted the load more than 6 inches making it a valid attempt, even though we only had one attempt. We passed the test and the presentation was successful.
The IMA of the Sprocket and Chain system was 1.67. The IMA of the idle pulley was 1 because we only had 1 support stand. The IMA of the first class lever wasa 1.08. The IMA of the Wheel and Axle was 1.
The total IMA of the system as 1.8. The estimated AMA was .88. The estimated efficiency of the entire machine was 23%.
We completed the task in less that 3 minutes. I would estimate around 15 seconds but I am not positive. It all depends on how fast/how hard you turn the first wheel.
Team Evaluation: Daniel Afshire was a great group member. He is great at working with a team. He had the brilliant design that we used. He is very easy to work with. Daniel followed our group norms. He was always willing to help and contribute to the group effort. Daniel overall did a good job.
Nathan Mara was also a great group member. He is great at thinking of ways to make things work with the VEX kits. He thought of the idea of how to do the frame of the machine, which worked great. He knows a lot about how to make things and how they work. He followed the group norms. He works well with a group and listens to what others have to say. He was always willing to help the group work and did his part. Nathan did a good job.
Ryan Sze was a good group member. He followed the group norms. He knows a lot about doing calculations and is really good at math. He is the one who came up with the idea and made the holster for the load that worked really well. Ryan was really interested in the pulley and tried many different ways to get it to work. Ryan tried to contribute as much as he could. Ryan did a good job.
I think I was a good group member.I followed the group norms. I listened to what the others had to say. I tried to contribute as much as I could. I assembled the lever and attached it to the other parts of the machine. I did as much as I could to help the team accomplish the goal. I was willing to do as much work as I could. I think I did well with this group.
Post-Mortem-
Daniel Afshar, Nathan Mara, Ryan Sze
POE 2
9/25/15
Project 1.1.6 Compound Machine Design
Design Problem: For this project, we are to design a compound machine that must lift a weight of approximately 8 ounces a vertical distance of 6 inches in less than 3 minutes.
The learning objectives was to understand how elements of design can affect mechanical advantage, understand how simple machines can work together to accomplish a task, compare the efficiency of different simple machines in a working situation, experience the capabilities and limitations of VEXⓇ components for future projects.
The criteria and constraints are: The applied effort force may
only be provided by a single human input. The final design must include a minimum of three different types of mechanisms. We MUST include any two of simple machines. The third mechanism can be any of the following: a gear system; a pulley and belt system; or a sprocket and chain system. Each required mechanism must have a mechanical advantage greater than 1. Final design must have a mechanical advantage greater than 1.
Brainstorm Idea:
For my idea, pull on a string that goes to a pulley, which leads to another pulley, then to one end of the lever. The lever moves down pulling on the string attached to another pulley, finally pulling up the load.
Final Design Proposal: We chose Daniel’s design because it scored the best on our design matrix. It is simple, and works. Our categories for the design matrix were: simplicity, time, trustability, resilience, and cleanliness.
We had simplicity because the most important thing was that it would work and we all understood it. Simplicity and time indirectly went together when we were deciding what design to use. We had a small time frame and did not want to have to rush everything because it would take so long to assemble the product.
We wanted to be able to trust that the product would work and we would not have to change everything we had on it to get it to operate correctly. We chose resilience as a category because having the product break on us would not be an ideal circumstance. Cleanliness was very important because having a mess to clean up afterwards would take up a lot of time that we could have to get measurements.
After our discussion and debate Daniel’s ranked the highest making it the winning design. In Daniel’s design we turn the gear on the right side, which turns a chain, turning another gear and a wheel and axle. From there a string wraps around a wheel then goes through a pulley. The string from there goes to the first class lever, pulling up on a string with a rope attached to it.
Design Modification:
We also added a sprocket to the center of the chain system to help it flow better with less slack and to have less rub. Adding the sprocket helped it very much and it worked better.Before it had a lot of friction and slack, after it had little friction and little to no slack.
We flipped the pulley upside down and secured it to the frame so it will be more secure and won’t wobble as much. This helped the system work for efficiently and it would wobble less. Before, the pulley barely worked, after the pulley worked very well.
We had to adjust where we start the rope on the wheel and axle so it will wrap the correct way. When we spun the wheel that the rope wrapped around it would fall down onto the axle which would tangle it, and it would decrease the mechanical advantage and would make it take a lot longer to lift the load. Wrapping it from the side closer to the frame fixed the problem the majority of the time.
We originally planned on having the load attached to a single string then on the the lever. It was difficult to attach our load to one string because our load was in the shape of a cylinder. We made a complex holster for the load that composed of 2 strings., and cradled the load. The holster held up and worked very well for what we needed it to do.
We made the lever longer so that we could have a greater mechanical advantage and it would be able to pull the load up 6 inches. To extend it we put 2 components of the vex kit together. Extending the load made it easier to lift the load the target distance with less effort force.
Final Design Proposal:
In the final product we still turned the wheel on the very right side. That wheel had a sprocket on the same axle that turned the chain. The chain turned the other sprocket, which had the other wheel on the same axle. The wheel turned and the rope wrapped around it. The rope went through the pulley to the lever. The lever then pulled the load up more than 6 inches.
During the presentation the machine operated as it was supposed to. The machine lifted the load more than 6 inches making it a valid attempt, even though we only had one attempt. We passed the test and the presentation was successful.
The IMA of the Sprocket and Chain system was 1.67. The IMA of the idle pulley was 1 because we only had 1 support stand. The IMA of the first class lever wasa 1.08. The IMA of the Wheel and Axle was 1.
The total IMA of the system as 1.8. The estimated AMA was .88. The estimated efficiency of the entire machine was 23%.
We completed the task in less that 3 minutes. I would estimate around 15 seconds but I am not positive. It all depends on how fast/how hard you turn the first wheel.
Team Evaluation: Daniel Afshire was a great group member. He is great at working with a team. He had the brilliant design that we used. He is very easy to work with. Daniel followed our group norms. He was always willing to help and contribute to the group effort. Daniel overall did a good job.
Nathan Mara was also a great group member. He is great at thinking of ways to make things work with the VEX kits. He thought of the idea of how to do the frame of the machine, which worked great. He knows a lot about how to make things and how they work. He followed the group norms. He works well with a group and listens to what others have to say. He was always willing to help the group work and did his part. Nathan did a good job.
Ryan Sze was a good group member. He followed the group norms. He knows a lot about doing calculations and is really good at math. He is the one who came up with the idea and made the holster for the load that worked really well. Ryan was really interested in the pulley and tried many different ways to get it to work. Ryan tried to contribute as much as he could. Ryan did a good job.
I think I was a good group member.I followed the group norms. I listened to what the others had to say. I tried to contribute as much as I could. I assembled the lever and attached it to the other parts of the machine. I did as much as I could to help the team accomplish the goal. I was willing to do as much work as I could. I think I did well with this group.
Post-Mortem-
- I think it was easiest to determine the Mechanical advantage for the pulley. I believe it was the easiest because it was an idle pulley and all we had to do was count the support stands.
- The most difficult to calculate the Mechanical advantage for was the sprocket and chain system in my opinion. We had a lot of parts attached to the system complicating it.
- I think to add to the mechanical advantage I would add a more efficient way of giving the effort force. To do that I would add more sprockets in the sprocket and chain system and a pulley to the beginning of the machine. I would add the sprockets to the bottom of the sprocket system touching the chain. Then attach a string and pulley to the system so I could pull the string instead of turning a wheel.
- One thing I would do differently is move the pulley farther away from the frame so that the string wouldn’t fall off of the wheel often. If we moved it farther away it would wrap a lot cleaner.