Latch V.3.5 AssemblyTags: Mechanical, Innovate, Design, and Think
Task: Assemble the V.3.5 latch and attach to the robot
We assembled the fourth version of the latch today. Some of the improvements on this latch include using bigger bearings and thrust bearings inside. This latch is designed to be stronger and more reliable. After cleaning the parts and trimming some edges, we assembled the pieces. Once the device was fully assembled, we wanted to reattach the latch to the inside of the polycarbonate Brackets. But before we could mount it, we discovered an issue; the gears required a different amount of pressure to catch the lock. If left untreated, it could result in the robot falling off the hook. We determined the root of this problem was that the locking mechanism on the right gear was shorter than the left. To fix this, we trimmed a few millimeters off the piece that provides tension on the left gear to match that of the right gear.
Older versions of the latch were previously mounted outside the polycarbonate bracket, but because the new latch had a c-channel bar on the back, we were unable to mount it to the front. We also needed more space, which we would achieve if we mounted it on the inside. On the previous latch, there were 2 metal bars on the top and bottom. These fit onto the brackets. We removed the bars from the previous latch and attached them to the new latch. These were too long and couldn't fit into the bracket, so we had to sand them down. This would allow them to fit inside the brackets, but even when they fit, the pre-drilled holes on the latch were too low. Our solution was to remove a portion of the bracket. We used a hacksaw to cut off a sliver of the bottom flaps, this allowed us to position the metal bar lower and attach it to the latch.
Latch attached to polycarbonate brackets.
Step-by-step instructions for building a latch:
Step 1: Determine priorities. We wanted our new design to be smoother, stronger, and easier to operate.
Step 2: Force your 3D modeler to model a design on a CAD software. We used Creo.
Step 3: Print out your model.
Step 4: Make the freshman build it. (They made Ben build it)
Step 5: Test, but don't break it so the seniors don't yell at you.
Step 6: Attach to robot.
We will need to perform various tests on the latch to determine if the height is correct, if the latch can support the robot, ease of latching and unlatching, and consistency. We plan to test our robot this Saturday at the DISD STEM Expo, which will provide an opportunity to practice latching.