Engineering Projects/Robot end effector/Howard Community College/Spring2012/p1501mjj2

Electronic Sections Expected

Problem Statement

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

Team Members

Summary

Over over second four week section on this project a lot of progress was made. We took from the foundations we previously built and pushed the project much further forward using new designs for our coffee grind hand to create a larger amount of suction. Found out that we may have been losing suction between the PVC and the balloon, so we added a little plastic PVC piece to create a better seal. The coffee gripper was finished and there was a lot of software understanding gained with getting the dc motor to go forward and backwards, also figuring out how to run twp stepper motors on one motor shield. With a lot of the physical pieces done there is less than half of the project that must be completed and hopefully it will be done soon.

Poster

Project Overview

Story

Again we all took to our own separate ways in hopes of gaining knowledge and products that could soon be put together for a final functioning result. Jon Fourney stuck with his coffee grind hand and practically finished it. He was having trouble with suction in the hand so he used a coupler inside of the drain to create a much more effective seal. He also discovered that putting a compressor to the balloon prior to the vacuum for picking up is much better. It inflates the balloon partially and allows it to conform to the desired object much easier. He cut it down to make it much more weight efficient. The to make the connection he simply used two threaded couplers, one of which connected to the makerbot wires and the other to the hand. This way it can be screwed in and out allowing for a quick change to the fin ray. Mike Hicks approach the product on the front of the motors and their function. First of all he built the mounts to hold the motors. In the stands the makerbot wire runs up through them and allows the motor to pull the wires up or push down and move as desired with the rotation of the stepper motors. Second he figured out the software issue. He found out how to make a motor work going up and down on a desired circuit so that we can control everything it does very easily. The only trouble he ran into was powering all of the motors at once on a single arduino. There was a problem or two with the motor shield but he should have this worked out shortly by using an external power source. Jonathan Sunday worked toward advancing his fin ray claw powered by a worm drive motor. The main source of his frustration was figuring out how to make the worm drive go in two directions. Making the hand close was very simple, but he could not figure out how to make it retract. After several days of extensive research and development he accomplished his goal. he can now make the motor go in both directions using the arduino with no problems whatsoever. All in all the project has taken large steps forward and it is going great.

Decision List

Different vacuum connections	wear and tare on balloon (1-least 10-highest)	greatest suction (1 best 10 worst)	Totals (1 being best 20 being worst)
Attach pvc coupling	1	3	4
Direct connection with hose	10	2	12
Keep hand how it was	2	5	7

Using the direct connection of the hose from the vacuum to the balloon may have been the best suction, but it would tip the balloon. Using the original design was not suctioning that well and only able to pick up light weight items, but wasn't ripping or stretching the balloon. Attaching the coupling was out best option, created the best seal to have a stronger suction in order to pick up heavier items and was putting no wear and tare on the balloon.

Material List

1. 2 Stepper motors

2. scrap wood

3. Sheet metal

4. external power supply

5. 12" shrink wrap

6. Metal rod

7. 2 rubber wheels

8. 2 Motor shields

9. 2 Hose clamps, $2

10. Male Threaded Coupling, $3

11. Female Threaded Coupling, $3

12. Maker Bot Wire

13. 2" Coupling, $2

14. PVC Glue, $6

Future Materials Needed

1. 1 arduino/motor shield

2. metal enclosure

3. wire

4. Sheet metal

Software List

Arduino software to control the dc motor and the tree stepping motors.

123d to design the coffee grind hand

Auto cad to design the coffee grind hand

Time

31 total hours

Tutorials

Next Steps

The next steps of the project are more of the difficult ones. A lot of kinks need to be worked out as far as powering multiple stepper motors on one arduino. Also we still need a completed finray claw to complete the end effector. After this a final installation must occur. Not yet have all the pieces each member has made been put together on the table. these pieces include mainly the motor mounts. Because these are the only part that is physically attached to the table permanently. After this most everything is interchangeable.