Engineering Projects/Robot end effector/Howard Community College/Spring2012/p1501mjj

Electronic Sections Expected

Problem Statement

Need to make a robot arm that will pick up objects.

Team Members

Summary

Our goal was to create a more efficient structure, and make interchangeable robot hands between the coffee grinds hand and the fin ray claw and to exclude the use of the original Lego motors/parts. The original coffee grind hand had been big and bulky so we down sized completely and cut the weight of it big time while keeping the ability to hold objects the same. As for the fin ray we redesigned the structure and leaned more towards a mechanical claw controlled by a motor with gears and an Arduino. As for the structure, we completely rebuilt a table top like surface out of wood that will support the robot grippers rather than the original cardboard box. Next, in order to replace the Lego motors/parts we created three push/pull devices that that run to the coffee/claw grippers. The motors we are using are three stepper motors that are controlled by Arduino's to push/pull each rod to have the arm mimic the moments or an elephants trunk and pick up anything underneath it.

Poster

Project overview

Story

To begin the project we all set off in our own general directions. Jonathan Fourney began work on the coffee grind hand, Jonathan Sunday the finray claw, and Mike Hicks began working with the arduinos. Fourney attacked the coffee grind hand armed with the knowledge of the previous group. He took the previously made hand that was slightly large for the teams taste and created a scaled down version. To do this he used a sink drain and some pvc couplings and created the basis for the hand itself. Which was less than half the size of the hand made by the previous group. Then came time for him to begin experimenting with the balloons. He used average birthday balloons, filled them with coffee and tried them in the hand. The problem was that the balloon was way to small and to much force was required in a downward fashion to grab anything. So he decided to get another balloon at a bigger size and try not only a coffee version, but a sand version. After rigorous experimentation with both he found that the sand hand worked much better and this is what he decided to go with. Then one day he started messing around with the hand and tried the balloons without the drain on the end. In doing this he found out that he was losing a tremendous amount of suction through the threads. This young man is currently trying to correct the problem. Sunday was tossed into this project and found himself perplexed at the task ahead. In order to overcome this problem he began extensive research on how to form an effective fin ray claw that was much more sturdy than the original paper constructed claw. He discovered a claw that gave him a great feeling of hope. This claw uses a worm drive motor to control the fingers themselves. This way the fingers did not have to bend and could be constructed of metal. By connecting the fingers to gears the worm drive motor will control its movement at the touch of a button that control the arduino. However, now he faces the challenge of how to keep the fingers in place around the motor. Hicks began his work devoted to learning the ins and outs of the arduino controls. This was very important because this function will be the brains of our operation. By studying how they function and looking up various tutorials he strengthened his knowledge of their function. In order to pin point the movement he decided to place a grid at the bottom where exact points can be made. This way we can discover the exact movement needed to hit each spot and record all of the data. Once finished it should prove to be very effective. Once all of each members work is done it will all be placed on a much more sturdy structure than the original cardboard box. We have made a table out of wood that will prove to be much more effective. Instead of lego motors we have gotten stepper motors that will control the movement of the arm itself. The arms eventually will be made so that they are interchangeable very easily. In the end this should prove to be a very successful project.

Decision List

Most of the formal decisions made were concerning the times in which we would meet up outside of class. Because we are all very busy people there were only limited times of certain days that we could meet up. So this was always a difficult process. We also had several arguments that turned to formal decisions after much debate. One big decision was how we would make the arm interchangeable,because this affected everyone's project a formal decision was necessary. The other was how we would split up who did what work. Because there are many aspects of the project that require different knowledge. Also the decision matrix below shows which material for the vacuum powered hand we want to use.

Materials Used	Quality scale 1-3 (3-best quality, 1-worst quality)	Max pickup weight(lbs)(1-min, 4-max) Total	Total time to create 1-10 (10-least time, 1-most time)	Total (Lowest-Worst Highest-Best)
caffeinated grinds	2	3	8	13
Sand	3	4	7	14
decaf grinds	2	2	8	12

Material List

1. List materials used, quantity, size, cost.

1. Sink drain

2. PVC coupling and bushing

3. Blow gun air nozzle

4. Coffee grinds

5. Sand

6. 12 inch balloon

7. Silicone

8. Air vacuum

9. Air hose

10. Sheet metal

11. Gears

12. 1 DC motor

13. 3 Stepper motors

14. 2 2x2 wood

15. Screws

16. Maker Bot wire

17. 2 Arduino's w/ motor shields

18. Scrap Wood

19. Arduino wires

20. Computer

Future Materials Needed

1. 2 Stepper motor

2. Paint

3. Sheet metal

4. Arduino

5. Pivot joint

6. Metal rod

Software List

1. Arduino Software- Used to program the Arduino's to control the motors.

2. AutoCad- Designed the coffee grind robot hand.

3. SketchUp- Designed the mechanical claw.

Time

52 hours total.

Tutorials

Next Steps

Because we all elected to stay on the project our next steps will mostly be fine tuning our current work and combining everything that we have done up to this point. We will need to connect the hands to the make bot wires connected to the motors. Next we will have to find a way to extend the hand out when needed. This is for the coffee grind hand because force must be applied downward for the balloon to surround the object so that it can get a hold of it. The plan for this is still up in the air and is not for certain yet. The finray claw still needs some work but is looking promising. Once a method to fashion the fingers to the motors is made it will be in working order. To future groups I advise them to expect a lot of construction type work. There is much more of this than computer work. Also to use bigger balloons and test to make sure a good vacuum is being created within the coffee grind hand. Other than that this is a really fun project and anyone taking it on will be pleased.