niall kirwan poster

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Aim and Problem Statement Pneumatic Knuckle Crane Pneumatic Knuckle Crane Niall Kirwan Niall Kirwan Bachelor Engineering Honors Degree Mechanical Engineering Bachelor Engineering Honors Degree Mechanical Engineering Material Selection Material Selection The aim of this project is to design and manufacture a pneumatic knuckle crane that will be able to lift up five hundred grams in weight and locate it to a different position. This system will be used to demonstrate the principles of pneumatics which is the transfer of pressure over different size areas to create a larger force on the power cylinder. Design Specification 1.The pneumatic knuckle crane had to be capable of lifting five hundred grams in weight and locating it to a different position. 2.The Prototype frame had to have structural durability due to the forces that it will be under. 3.The frame had to be kept as light weight as possible to reduce the forces over the entire pneumatic system. 4.The design had to cost less than €50. 5.The cylinders had to be able to withstand the pressures that will be opposed on them. 6.The arm had be able to turn on its axis about an angle of at least ninety degrees. 7.The cylinders had to be fitted to the arm so that they are secure and there is no risk of them disengaging from the frame. Further Further Developments Developments Pneumatic system Conclusion Conclusion The knuckle crane achieved the objective which was to lift a five hundred gram weight and locate it to a different position. It outperformed the objective by lifting six hundred and fifty grams in weight. The crane can be used in the teachings of the principles of pneumatics and there are resources available to help with future developments in relation to the implantation of hydraulics as the power supply.. Frame Design For the Manufacturing of the knuckle Crane the design was based on the generic construction of the crane as shown in the picture below. It consists of a Mast and articulating Jib and Boom. A Plastic base to which the Mast will be mounted on such on which the crane will rotate. Hinges for the Mast, Jib and Boom to allow for free movement in relation to each other. Pneumatic cylinders to raise and lower the Boom and Jib. Ji b Mast boom and jib For the main frame of the arm aluminium extrusion was used because it is vvery light at only 0.5 kg/m , easily machined, and the whole located down the middle of the extrusion when tapped was used to join the different sections of the model. Also there are many accessories like hinges and T- slot that were able to attach to the extrusion. Cylinder Brackets The cylinder brackets which secure the bottom and top ends of the cylinders to the frame were manufactured out aluminium sheet metal 0.5mm thick. The reason for this is due to the shape of the brackets the material used needed to be easily machined and light as not to not add unnecessary weight to the boom and jib increasing their standing moments. Ram Connections To connect the cylinders rams to the cylinder brackets of the crane T- joints were manufactured by taking advantage of the selective laser sintering machine. It uses a carbon dioxide laser to fuse small nylon particles into the desired three dimensional shapes. They screw onto the end of the ram and a pin is placed through a cylinder bracket through the T-joint though a second bracket. These T-joints allow free movement of the cylinders when they extend and retract. Pneumatic system In order to have begun the constructing the pneumatic system for the knuckle crane there are a couple of questions that need to be answered. 1.Placement of the cylinders relative to the boom and jib. 2.How would the frame rotate? 3.What forces would the cylinders encounter and how big will they be? 4.How big to the cylinders needed to be in order to overcome the forces that are being exerted on them? 5.The size of the travel lengths of the cylinders and how would that relate to the movement of the jib and boom. Principle formulas used to answer the above questions Force = pressure x Area = Force x Perpendicular distance from Calculate forces Theoretical max load = 660 grams Linear Actuator Ten millimetre bore Cylinders were used as they provide a forces of 55 Newtons when they extend our retract. Forces with no added weight Forces with added weight (500g) Cylinder one (Boom Cyl) 14.04N 44.89N Cylinder two (Jib Cyl) 7.308N 44.92N Rotating the Crane Frame To rotate the frame a compact rotary table was used that is capable of exerting a torque of 110 Newton’s which will be more than efficient considering the overall weight of the frame plus cylinders is only 550 grams in weight. Pneumatic flow controller In relation to the flow control of the pneumatic system I will be using a five port three position directional control flow value that will give the most control over the cylinders. It will give me the capability to full extend and retract the cylinders as well as extend and retract them but to a mid-position. Control over the pneumatic system Controlling the pneumatic system will be done using solenoids to operate the directional valve; these solenoids will be wired to a remote that will be used Testing Testing Testing of the pneumatic crane involved applying an air supply of 7 bar and testing all of the individual pneumatic devices separately. Once that was complete the devices were attached to the frame of the crane and loads increasing in weight were placed at the end of the arm. The weights were added until such a time when the arm of the crane would no longer raise from it original static position. While this procedure was carried out the remote was used to control the solenoid values to investigate whether the cylinders would extend and retract to a mid position. Results Results In total the knuckle crane was cable of lifting 650 grams of weight, 150 grams greater than the In total the knuckle crane was cable of lifting 650 grams of weight, 150 grams greater than the stated objective. In comparison to the theoretical results of 660 grams there is only a stated objective. In comparison to the theoretical results of 660 grams there is only a discrepancy of 10 grams our a 1.8% error. This justified the accuracy of the calculations. While discrepancy of 10 grams our a 1.8% error. This justified the accuracy of the calculations. While the knuckle crane operated in such a manner that it achieved its objective it was notice that the knuckle crane operated in such a manner that it achieved its objective it was notice that the compact rotary table did not stay static in is mid position but returned to its original the compact rotary table did not stay static in is mid position but returned to its original position. This a because of the flow control value leaking pressurized air. Unfortunately the position. This a because of the flow control value leaking pressurized air. Unfortunately the valve is to expensive to order a new one. With this said the overall testing of the pneumatic valve is to expensive to order a new one. With this said the overall testing of the pneumatic knuckle crane was a complete success. knuckle crane was a complete success. Future developments of the knuckle crane could be to attach a second boom cylinder to the mast such that the crane could be capable of lifting a weight of one kilogram. Another development of the knuckle crane could also be to implement hydraulic power instead of pneumatics to show the comparison and differences between them, that is hydraulics power offers more control over pneumatic power but pneumatics is far cleaner.

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Page 1: Niall kirwan poster

Aim and Problem Statement

Pneumatic Knuckle CranePneumatic Knuckle CraneNiall Kirwan Niall Kirwan

Bachelor Engineering Honors Degree Mechanical EngineeringBachelor Engineering Honors Degree Mechanical Engineering

Material SelectionMaterial SelectionThe aim of this project is to design and manufacture a pneumatic knuckle crane that will be able to lift up five hundred grams in weight and locate it to a different position. This system will be used to demonstrate the principles of pneumatics which is the transfer of pressure over different size areas to create a larger force on the power cylinder.

Design Specification 1.The pneumatic knuckle crane had to be capable of lifting five hundred grams in weight and locating it to a different position.2.The Prototype frame had to have structural durability due to the forces that it will be under.3.The frame had to be kept as light weight as possible to reduce the forces over the entire pneumatic system.4.The design had to cost less than €50.5.The cylinders had to be able to withstand the pressures that will be opposed on them.6.The arm had be able to turn on its axis about an angle of at least ninety degrees.7.The cylinders had to be fitted to the arm so that they are secure and there is no risk of them disengaging from the frame.

Further Further DevelopmentsDevelopments

Pneumatic system

ConclusionConclusionThe knuckle crane achieved the objective which was to lift a five hundred gram weight and locate it to a different position. It outperformed the objective by lifting six hundred and fifty grams in weight. The crane can be used in the teachings of the principles of pneumatics and there are resources available to help with future developments in relation to the implantation of hydraulics as the power supply. .

Frame DesignFor the Manufacturing of the knuckle Crane the design was based on the generic construction of the crane as shown in the picture below. It consists of a Mast and articulating Jib and Boom. A Plastic base to which the Mast will be mounted on such on which the crane will rotate. Hinges for the Mast, Jib and Boom to allow for free movement in relation to each other.Pneumatic cylinders to raise and lower the Boom and Jib.

Jib

Mast boom and jibFor the main frame of the arm aluminium extrusion was used because it is v very light at only 0.5 kg/m , easily machined, and the whole located down the middle of the extrusion when tapped was used to join the different sections of the model. Also there are many accessories like hinges and T-slot that were able to attach to the extrusion.

Cylinder BracketsThe cylinder brackets which secure the bottom and top ends of the cylinders to the frame were manufactured out aluminium sheet metal 0.5mm thick. The reason for this is due to the shape of the brackets the material used needed to be easily machined and light as not to not add unnecessary weight to the boom and jib increasing their standing moments.

Ram ConnectionsTo connect the cylinders rams to the cylinder brackets of the crane T-joints were manufactured by taking advantage of the selective laser sintering machine. It uses a carbon dioxide laser to fuse small nylon particles into the desired three dimensional shapes. They screw onto the end of the ram and a pin is placed through a cylinder bracket through the T-joint though a second bracket. These T-joints allow free movement of the cylinders when they extend and retract.

 

Pneumatic systemIn order to have begun the constructing the pneumatic system for the knuckle crane there are a couple of questions that need to be answered.1.Placement of the cylinders relative to the boom and jib.2.How would the frame rotate?3.What forces would the cylinders encounter and how big will they be?4.How big to the cylinders needed to be in order to overcome the forces that are being exerted on them?5.The size of the travel lengths of the cylinders and how would that relate to the movement of the jib and boom.

Principle formulas used to answer the above questionsForce = pressure x Area Moment of a Force = Force x Perpendicular distance from the pivot

Calculate forces

Theoretical max load = 660 grams

Linear Actuator Ten millimetre bore Cylinders were used as they provide a forces of 55 Newtons when they extend our retract.

 

Forces with no added weight

Forces with added weight (500g)

Cylinder one (Boom Cyl)

14.04N 44.89N

Cylinder two (Jib Cyl) 7.308N 44.92N

Rotating the Crane FrameTo rotate the frame a compact rotary table was used that is capable of exerting a torque of 110 Newton’s which will be more than efficient considering the overall weight of the frame plus cylinders is only 550 grams in weight.

Pneumatic flow controllerIn relation to the flow control of the pneumatic system I will be using a five port three position directional control flow value that will give the most control over the cylinders. It will give me the capability to full extend and retract the cylinders as well as extend and retract them but to a mid-position.

Control over the pneumatic systemControlling the pneumatic system will be done using solenoids to operate the directional valve; these solenoids will be wired to a remote that will be used

TestingTestingTesting of the pneumatic crane involved applying an air supply of 7 bar and testing all of the individual pneumatic devices separately. Once that was complete the devices were attached to the frame of the crane and loads increasing in weight were placed at the end of the arm. The weights were added until such a time when the arm of the crane would no longer raise from it original static position. While this procedure was carried out the remote was used to control the solenoid values to investigate whether the cylinders would extend and retract to a mid position.

ResultsResultsIn total the knuckle crane was cable of lifting 650 grams of weight, 150 grams greater than the stated objective. In comparison to the In total the knuckle crane was cable of lifting 650 grams of weight, 150 grams greater than the stated objective. In comparison to the theoretical results of 660 grams there is only a discrepancy of 10 grams our a 1.8% error. This justified the accuracy of the calculations. While theoretical results of 660 grams there is only a discrepancy of 10 grams our a 1.8% error. This justified the accuracy of the calculations. While the knuckle crane operated in such a manner that it achieved its objective it was notice that the compact rotary table did not stay static in is the knuckle crane operated in such a manner that it achieved its objective it was notice that the compact rotary table did not stay static in is mid position but returned to its original position. This a because of the flow control value leaking pressurized air. Unfortunately the valve is to mid position but returned to its original position. This a because of the flow control value leaking pressurized air. Unfortunately the valve is to expensive to order a new one. With this said the overall testing of the pneumatic knuckle crane was a complete success.expensive to order a new one. With this said the overall testing of the pneumatic knuckle crane was a complete success.

Future developments of the knuckle crane could be to attach a second boom cylinder to the mast such that the crane could be capable of lifting a weight of one kilogram. Another development of the knuckle crane could also be to implement hydraulic power instead of pneumatics to show the comparison and differences between them, that is hydraulics power offers more control over pneumatic power but pneumatics is far cleaner.