User:J4knee21/enes100/My Work3

Write problem/project Goal
Elephant truck style robot arm with interchangeable hands.

My First Task
Create and do some testing with a fin ray claw.

Summary of actual work over first weekend
I went in a new direction in how to construct the claw itself.

Week1 Narrative
I decided to go in a different direction. Instead of the hinged and metal version of the fin ray claw I decided to go with a better material I hope. The metal I feel wont exactly work out for me. It will be really stiff to bend and just an all around pain. But I also wanted something that will last longer than the original paper or cardboard. So I decided to explore plastics. What I decided to try and use is the plastic of a thin cutting board. It is really narrow and flexible while inexpensive. The only problem that I have encountered is how to connect the ribs that go inbetween the triangle to effectivley make it bend. That is what I am currently working on and hope to find a solution soon. I was thinking maybe some sort of clamp configuration because welding or glue could break easily. It could possibly work cutting slits in the plastic and sliding the pieces through to keep them together. I have confidence that I will find a way to accomplish this soon. But in the mean time here is a sketch of what the final plan is for the fin ray. :

My Second Task
Continue with putting together a claw using plastic

Summary of actual work over second weekend
I made an original fin ray. It is still a little rough, but I have the general concept of the design down.

Week2 Narrative
So to kick off my weekend I went to Home Depot and got everything I thought I would need to build the claw. I got a Male coupler (2"), two 2" plugs, a 4" cap, three 1/4" bolts with nuts/washers, a package of springs, and a flexible plastic cutting board. I took all of the plugs and caps to the band saw and cut them down so they were only the flat round piece. The 4" goes directly to the coupling. Then the 2" is bolted to the 4", however, in between them are springs to keep the hand extended. This portion came along pretty well and easily connected to the arm. : . Then creating the fingers of the claw is where the trouble came along. I tried several different methods and failed on several attempts. I began with the conventional triangle shaped claws with ribs in between them. But with my new cutting board material super glue would not stick very well at all it kept falling apart on me. Then I tried using a method of weaving two pieces of plastic together to try and hold them together. But it really did not want to curl like it should so this idea :     ... was quickly tossed aside and I moved on. Then I was struck by another idea. I cut the plastic into a shape that almost resembled a spider with three legs. One smaller for the 2" and one bigger for the 4". :   . Then these get holes drilled in them so that they can just be connected by the original bolts really easily. Then on the tips of the smaller piece of plastic I cut slits about half an inch from the bottom. The the tips of the bigger piece I cut them down so it would slide through and it connected at the end. From there it was working somewhat, but still pretty weak. This is usually where the ribs come into play but i could not glue them in. So what i did was put rubberbands around the fings to curl it up. This stiffened the fingers a lot and made it much stronger. It could still use some work but its coming along well. :[Fin Ray Video]

My Third task
Create a bracket with an I hook to connect the claw to the motor and try to improve the claws efficiency and grab ability.

Summary of actual work over third weekend
Created the bracket to connect the claw to the string from the motor.

Week3 Narrative
So to make the bracket I needed a round piece of material that would connect to the three bolts. So I used a board and cut it into a circle that was just under the circumference of the hand. This way it can still slide up and down easily with no trouble. Then in the middle of this board I placed a eye bolt. The eye bolt is what will connect to the string and allow it to be pulled. Over all it was pretty simple yet very effective. Here is a picture of the finished piece. .

My Fourth task
Adjust the width of the fingers so that that it will close having a more solid fit with no gaps between them.

Summary of actual work over fourth weekend
How is what you did different than what you planned?

Week4 Narrative
Tell a detailed story describing what you did for your team over the weekend.

Complete Team Page
Fill out the Team Form (should have already copied the form, created the team page, linked to it and started filling it out).