Size and Strength Test
The goal here is to ensure that the mechanism can handle the mass and size of the parts that will be combined and wound with filament. The test is very simple. It comprises of setting up the mechanism in the start position, and loading the parts on. Then, step by step ensuring that there will be no collisions of failures in the physical motions, go through the movements involved with the process. At the extreme points of motion (for example, when an axis is fully extended or collapsed) check the mechanism for stability and collisions. This test will prove requirements 9 and 10. Procedure
1. Set up mechanism
2. Place parts on mechanism
3. Start mechanism
4. Step through code, checking movements of mechanism
5. Stop mechanism
6. Remove part
Results
If this test is completed successfully, the mechanism will be able to support the mass of the robot arm parts, and there will be no collisions between parts, and the mechanism. If something were to go wrong, it would be one of three possibilities: mechanism cannot bear the mass of the parts, or a collision between moving members of the machine and part, or finally, a combination of the two previous possibilities. If there is a collapse due to excess mass, the frame will need to be reinforced in the areas of damage. In the case of major collapse, a re-design of the frame may need to occur, where stronger material may be used, and/or a more sound mechanical design implemented. If there is a collision, the program controlling the mechanism needs to be addressed, possibly specifying via points for the moving members to pass through to avoid hitting other objects.
Product Completion Test
This is another simple test, it comprises of running through the process to make sure that the completed part is in one piece and is completed covered in filament. Without this being accomplished, the project will be of no use, since the main goal is to design a process that creates a part that combines the link and joint by winding filament around them. This test will show that requirements 4 and 5 can be met.
Procedure
1. Set up mechanism with parts to be wound
2. Run the machine with all components functioning
3. Turn off mechanism
4. Check part for cohesiveness and complete covering by filament
Results
The successful result of this test would be a singular part completely covered in filament, while an unsuccessful candidate will be in two parts, not covered in filament, or both. A variation of an unsuccessful test would be where there is a singular part created, but there is movement between the link and joint. To fix these problems, the method in which the filament is wound around the parts will need to be revised, as in the direction and angle the filament is being applied.
The successful result of this test would be a singular part completely covered in filament, while an unsuccessful candidate will be in two parts, not covered in filament, or both. A variation of an unsuccessful test would be where there is a singular part created, but there is movement between the link and joint. To fix these problems, the method in which the filament is wound around the parts will need to be revised, as in the direction and angle the filament is being applied.
Resin Application
This test ensures that the resin is applied to the filament in a timely manner, such that it will not cure before be wound on to the link and joint. To accomplish this, the resin must be allowed to dry completely, and the time noted. This time must be compared to the time required to move the filament through the resin bath to being on the part. If it takes longer for the resin to cure than the time needed to wind the resin coated filament onto the part then requirements 2 and 3 will be fulfilled.
Procedure
1. Set up filament supply and resin bath
2. Run filament through bath and start timer
3. Let resin cure, stop timer when resin has cured
4. Set up mechanism
5. Run set-up with filament and resin, start timer
6. Finish winding part, stop timer
This test ensures that the resin is applied to the filament in a timely manner, such that it will not cure before be wound on to the link and joint. To accomplish this, the resin must be allowed to dry completely, and the time noted. This time must be compared to the time required to move the filament through the resin bath to being on the part. If it takes longer for the resin to cure than the time needed to wind the resin coated filament onto the part then requirements 2 and 3 will be fulfilled.
Procedure
1. Set up filament supply and resin bath
2. Run filament through bath and start timer
3. Let resin cure, stop timer when resin has cured
4. Set up mechanism
5. Run set-up with filament and resin, start timer
6. Finish winding part, stop timer
Results
A good resin application test will demonstrate that the filament can be coated in resin and applied to the part without curing; a poor result will have the resin curing before being completely applied to the part. To fix this, the process would need to be sped up, and possibly move the resin bath closer to the payout eye to minimize time and distance between the filament travelling through the resin bath to be wound around the part.
Filament Application
The filament application test deals with the tension, torsion and resin coating of the filament as it is wound around the part. This will be done by feeding the filament through the resin bath and payout eye as it would be done in an actual run of the process, but instead of winding it on an actual part, a simple tube will be used in its place. Filament will be wound around this tube for several meters of filament. Afterwards, the filament will be checked for and even coating of resin and tension in the winding. If done properly, this test will prove requirements 2 and 6. While it is not necessary to use a robot arm for winding the filament on, since the focus is on how the filament is wound not what it is be wound around. However, if desired a robot arm can be used, or a piece of similar geometry and mass can be used, instead of a generic tube.
Procedure
1. Set up resin bath and a tube for winding
2. Start winding filament around tube
3. Check winding for consistency in torsion, tension and even resin coating
Results
The anticipated successful result of this test will have a consistent tension, torsion and even coating on the filament. This means that the filament is not loose anywhere, nor is it so tight it is causing strain on the part, mechanism, or itself. Also, there is a normal amount of spin in the filament when being applied to the part, and finally an uneven coating of resin on the filament will weaken the part and possibly not combine the link and joint completely, which would violate requirement 4. Potential for poor results could be where the filament is stretched too tight, or there is too much torsion that it breaks, or so loose that it falls and sticks to objects other than the arm between the payout eye and the arm. These problems could be fixed by adjusting the speed at which the filament is fed through the mechanism.
Automation TestThis test consists of running the process of winding the robot arm in filament through with as little human interaction as possible. The reason for the automation is to speed up the manufacturing of the links and the more the process is automated the fast it can be done. This test will illustrate that requirement 1 can be met.
Procedure
1. Attach the link to the motor.
2. Check all the connections of wires.
3. Turn on the controllers.
4. Start running the program with a hand on the emergency stop button, ready to stop the program if any problems occur.
5. While program is running, continuously check for any problems with the program or the process itself.
Results
A successful outcome of this test is that the winding process will run through without any direct human help. It is expected that there will be a few problems during the first run of the process. A successful first run would be one with few problems and any problems which do arise could be fixed with very simple changes. A failure in the automation test would result in many large changes having to be made to the controller programming. The length of time required to make the changes to the program depends on how much of a failure this test was.
Weight and Payload TestThis test is used to determine that the wrapped robot arm meets the requirements for payload of the arm as well as the low mass of the link. This test is very simple and consists of attaching a weight to the end of the link to show that it will hold up to the 50kg payload required by requirement 7. Determining the payload will also show the high payload to weight ratio required by requirement 8.
Procedure
1. Weigh the finished link with a scale.
2. Attach 50kg of weight to the end of the link.
3. Raise the link up to allow the link to support the whole mass of the weights.
1. Weigh the finished link with a scale.
2. Attach 50kg of weight to the end of the link.
3. Raise the link up to allow the link to support the whole mass of the weights.
Results
The expected outcome of this test is that the link will be able to fully withstand the weight of the masses attached to the end. A catastrophic failure would be the link not being able to hold the mass and fracturing. This could be fixed by examining the path in which the link is wrapped and the filament being used. A few small changes in width of filament or a change in path could increase the allowable payload to the required 50 kg.
The expected outcome of this test is that the link will be able to fully withstand the weight of the masses attached to the end. A catastrophic failure would be the link not being able to hold the mass and fracturing. This could be fixed by examining the path in which the link is wrapped and the filament being used. A few small changes in width of filament or a change in path could increase the allowable payload to the required 50 kg.
