Final Team Documentation

The class is finally coming to an end, and below are some last updates and detail description of our final project:

Defense:

We considered our most critical component as the defense part. For that, we stick to the original plan and build a cart that prevents opponent from driving over while having a scissoWr linkage to block the arm. We built the cart body out of aluminum plate as planned. For the cart base, instead of using 1/4" acrylic plate, we decided to go with 1/8" Hardboard, the main reason being due to material composition, it'll be harder to drill and screw on the acrylic plate, while wood board will provide same sturdiness and strength as acrylic plate.

For the boards that hold scissor linkage together, we drilled an extra hole to make the linkage 1 degree of freedom. After screwing the scissor linkages together we realized the screws come down really easily. Therefore, we used super glue to secure the plates together.




Please see pictures below for finished product:

The wiring/shaft & motor/scissor linkages & plates close up inside the cart.

Exterior of the cart body. The PVC pipe, which is used to connect to the PVC block of the arm, beside the wheel is replaced with time belt pulley to connect to the fixed motor. The rubber bands on wheels are replaced with velcro and sand paper to increase traction.

Offense: Mechanical Arm

Instead of building the pump that contract balls and transport to the other side as we proposed, we decided to go with a very simple mechanical arm design. The arm is made out of aluminum plate. The 1/4" aluminum rods, which are used to connect to the PVC block mounted to the arm, are used to screw the block on the fixed axis. The arm is mounted to a block, which is screwed to the fixed axis on the arena. There is a scoop on the arm, so it can pick up balls easily. When the arm is powered by motor, it will rotate and swing the balls to the other side. Originally, we were going to make the arm go in clockwise direction. However, after testing, we found out it is easily to swing the balls over in counterclockwise direction.

-CAD model for mechanical arm-

-CAD drawing for the mechanical arm-

See pictures below for product:





See: Final Bill of Materials

11-30 Week Progress Report

10 Days Countdown until Design Expo! Our team is making much progress in hopes that our machine will perform well on the competition. It's very exciting to see that our design actually comes out well and has feasible functions. So below is a few updates on the project this past week:

• We made several modifications on the cart. Last week, we spent plenty time trying to lathe the shafts due to different gear and wheel sizes. We got that working now. In addition, we also fixed our Most Critical Module, the scissor linkages, and add the release mechanism to make sure the module can successfully fall down and perform its task of blocking. Please see below for the product pictures.

• For the offense mechanism, we made a very flexible decision and decided to go with a very simple mechanical arm. It's an arm that's attached to a block that connects to the fixed axis. The arm has a rotary motion, and it picks up balls and swings them to the other side. Again, please see below for pictures.

• One of the major problems during manufacturing was figuring out lathe. We spent a lot of time threading the rod that goes into the block for the arm. We've attached a CAD copy, and that's a pretty nice representation of what we have.

• On a side note, in order to protect the arm/arena slot, as well as creating traction on the mechanical arm, we taped the arm with red wire tape. Kyle, being the big Red Wing fan that he is, is very pleased with the product. And later on, we will also logo it with superman block! ;)

Excitement ensures as the clock ticks away!