Sprint 5 - Specimen Grabber Improvement (Kailyn)

[kailyn-s]

With our current design, we've implemented two metal brackets powered by a servo motor. Though this has shown effective in picking up specimens to score on the high chamber, we've noticed that it requires a huge amount of time to pick up specimens laid on top of the edges. With this, we've decided to change the format of our grabber to create a more efficient pick up, and transfer the time spent picking up the sample to time spent scoring other elements.

Deadline: December 6, 2024

Overall Objectives

• Research rubber wheels that can increase the efficiency of picking up specimens
• Implement specimen grabber into autonomous program to score additional points during the autonomous period

Objectives for this Period

• Research possible materials to be used for picking up specimens
• Obtain all necessary parts to begin building
• Design a thorough plan to organize the building process efficiently
• Build a prototype for the grabber

[kailyn-s]

Tuesday, December 3

Today I began with creating a prototype for the new intake. We decided that the biggest change that needed to be made was the material of the grabber. Previously, we used two metal brackets, but found that it didn't hold well and it required a lot of accuracy. Therefore, we decided to use rubber, a material that would have more friction and allow us to require less accuracy when grabbing specimens. Below is a photo of how we plan to incorporate the rubber wheels into the previous design.

Issues

• gear sizing maybe have to be changed as the wheels are bigger and require more spacing in between
• the end of grabber is intended to hold the wheel inplace but seems too large and may get in the way of picking up specimens

[kailyn-s]

Wednesday, December 4

Today I continued building the grabber design with rubber wheels as discussed with the first half and attached it to the servo to be able to vision the movement of the two parts together in order to pick up a specimen. Since this is purely a prototype, there are many flaws that pose a discrepancy to the pick up of samples as many parts and screws are interfering due to their excessive length. In terms of gear sizing, we plan to stick with the current ones; the claw does not have to begin completely shut as it doesn't give any advantage. We began discussing whether using the rubber wheels would be the best option, compared to a plastic claw. Furthermore, we discussed whether it would be better to use the rubber wheels purely for their material alongside a claw, or put them on a hex shaft to have a spinning car wash type grabber.

Issues

• screws are sticking out and interrupt the grabbing process as it hits the specimens
• the end of the grabber to hold the wheels in place is too large
• the arm that the grabber mounted on is angled towards the ground, meaning the grabber may touch the ground if extended too long
• rubber wheels are bulky

[kailyn-s]

Thursday, December 5

Today, I explored other options for the grabber, including methods that would not involve the rubber wheels. With feedback from the senior team, we decided to implement a plastic claw design using 135 degree angle brackets as a simple claw to pick up specimens. We found the advantages of this was that it was less bulky, cleaner, and more simple; however, the main disadvantage was the decreased friction due to the lack of rubber on the contact point. After building this design, we coded new restrictions with the servo programmer, but had many issues with the programmer itself. Tomorrow, I plan to begin programming this part.

Issues

• many pieces sticking out that need to be accounted for

[kailyn-s]

Friday, December 6

Absent

[kailyn-s]

Sprint 5 Review

Over the course of this sprint, my main focus has been on completing prototypes that demonstrated the different possibilities we had to use as the specimen grabber. Since we previously realized our former specimen grabber was heavily flawed making it difficult to pick up specimens efficiently, we wanted to create a new build that allowed us to speed up the process of picking up and placing specimens. With this, I explored various options such as different materials and shapes that could potentially make it easier for drivers during this process. I came up with two main ideas: One involves the use of rubber wheels as grabber to significantly increase the friction between specimens and the grabbers, and one involves the use of a plastic claw to allow a simple pick up. The rubber wheels seemed better to hold the specimen as the friction made it less prone to falling out of the grabber; however, the plastic claw was better to pick up the specimen as it was able to open wider and had a smaller contact point, making it easier to contact with the specimen in a short amount of time. Next week, we plan to put back together the robot to test the different grabbers in terms of efficiency, accuracy, and proficiency.

Issues:

• the plastic claw has very little grip on the specimen, meaning it is prone to being dropped, especially at high speeds
• the claw seems quite weak
• many parts are standing out as this is only a prototype and many lengths and measurements haven't been accounted for
• the gears tend to unmash often; during matches, they would have to be adjusted after each match

Next Objectives:

• put together the robot and rewire everything so that these two grabbers can be implemented and tested
• record data such as efficiency and productivity of both options to determine the more proficient option to use in competition
• with the chosen grabber, improve the build so that the parts don't impede the pick up process of specimens or other aspects (this may include finding shorter hex shafts, adding shaft collars to the ends to hold parts in place, replacing gear and screw sizes, etc.)