<<Step 4: Brainstorm ideas for the supports that hold the End-Effector
<<Step 5: Build the supports to hold Gripper
THE FINAL PRODUCT
This is the final layout of the entire build.
Design Problems: -Building the chassis with a holder to lift the gripper -Implementing a code to move servos up and down and to close the gears
Challenges: -The rough surface of the shells -The stage of printing out the model and so many trial and errors -Leveling out the entire build while keeping a level claw with the wooden linkages
Problems We Ran Into:
1.)One of our first problems was how are we were going to make our gears spin without too much friction on the plates that held it together
2.) Our second problem was how were we going to connect the gripper to the base of the chassis
3.) How to build the supports so that the ladder can go up and down smoothly.
4.) Coding the servo(ladder) to where it goes up and down at the right spot and coding the servo that closes the gripper to a point tight enough for the block to be held.
5.) 3-D printing the gears and linkages to exact measurements but they during the process they'd curl up.
Constraints: -How much weight the gripper can hold without dropping the object -How much friction the gears have on them even with spacers and no top shell -How much power the servo has to push through the friction on the bottom of the gears -3 weeks to build our gripper and end-effector holder
Changes We Made:
1.) We changed the front and back wheels so that we could get better grip and to balance the gripper.
2.) Using one shell instead of two for the outer layer that held the gears in place.
3.) Instead of putting a linkage in the middle of the gear with two different materials we glued it to the top of the gear. (No top piece which means no friction on the top of the gear)
4.) We changed the material we were gonna use for the gears and linkages.
Summary: This build was suppose to be powered from two servos. One controlled how far the gripper could go up and down to grab the Lego block. And the second servo had an axle going through a gear which rotated it and rotated two other ones causing the claws to shut. We screwed the base of the end effector to the rail on the ladder. We used this build because it seemed the most efficient.We each made a pros and cons list for the build we wanted to try and compared them. The build we chose was the most ideal.
Definitely a lot to improve on with the build. Like the actual gripper and how it actually grab the object because if the gears rotate too much the linkages twist in ways they shouldn't. Another way is how I had to put on rubber bands to get the right gear connection. On CAD it looked good but when we actually printed it out and tried to rotate them it wasn't enough so I came up with the idea to use rubber bands on the poles that kept the gears in place. And prototype one also let us know what all we need to correct because using glue on the linkages was not good enough. Plus the linkages were to thick which caused a lot friction with the other linkage and screw. So from all that we know to think harder on what we build and prototypes play a big role on how the final product will turn out.
The supports to hold the gripper was perfect I say but the gripper isn't that strong. And while working on the prototype half way through it we realized how much friction each gear had which put more pressure on the servo controlling them. So from that lesson we added spacers to lift the gears and linkages which kept them balanced.