Expense Report and Trade Form

Link to the Expense Spreadsheet:
http://spreadsheets.google.com/ccc?key=0AofiS4ctRuXxdGtDWTFDUEdhdF9UMjVla1dMWmNVdnc&hl=en

Link to the Trade Spreadsheet:
http://spreadsheets.google.com/ccc?key=0AofiS4ctRuXxdG50T2VrZUsyYW9aalhuVWRUM0tvWkE&hl=en

Stiga Pregame Video

Week of Nov 29th - Dec 5th

This week we were able to fully assemble and start testing our machine. When we started testing, we came across a couple of problems. First, the leadscrew was not able to fully pull up the hopper. To help the leadscrew, we designed a pulley system using our last motor to help to lift the hopper. Second, the hopper was getting stuck on the pins that were holding the wheels. To prevent this, we built a metal extension piece to force the hopper to stay in the middle of the cart. We also designed and built our final piece that would hold the double gear box motor for the wheels in place. We used the 1/16 aluminum plate and used the metal bending machine to bend both the piece the forcing the hopper in place and the motor base. We fully installed all the motors, soldered the wires to them and attached banana plugs.

We were able to first test with the box on Friday. The cart wheels were not able to turn intially so we changed gear ratio to the highest ratio possible. This allowed the cart to move, but it moves much slower than we expected. We also have Also we were able to pick up muliple rows or balls, including the heavy balls when we tested, but doing this required much more time than the 2 minutes will be be allowed in the competition. Sunday we were able to continue testing and make small modifications that would allow our machine to run more smoothly. We were also able to pratice more using the machine and learning how to work it. We also discovered that the slot on the second arena is less wide than the slot on the first arena, so when we compete in the final competition, we need to compete on the first arena.

Next week, we will have to continue testing and making small modifications as more problems arise to make our machine preform better.

Updated Schedule

Updated Schedule :

http://spreadsheets.google.com/ccc?key=0AofiS4ctRuXxdGgzeGFTeGMxSU55TzZEZjNEZlpMUUE&hl=en

To do: Week of Nov 30- Dec 4

Lathe 4 cart wheel axles for the e-clip grooves and attach wheels to the axles.

Laser cut holes in top of cart for lead screw and to attach scissor arm base.

Drill holes in cart horizontal pieces for the wheel axles to go through to connect to the motor.

Make Motor base to mount the motor for the wheels and coupe to shafts

Finish all lead screw machining that was started last week

We recently discovered that is it very hard to lift the scissor arms up so we need to engineer and machine a pulley system to help lift and retract scissor arms.

Assemble everything/ epoxy anything else that can’t attach using screws

Week of November 23rd

This week, we finished assembling the MCM (hopper+scissor arms), we cut and drilled holes in the cart bases, we finished drilling holes in the L-connectors, and we started manufacturing the leadscrew module.

We already had the springs/spring flaps secured to the hopper columns, and all of the columns secured to the hopper top. We finished the assembly of the hopper by weaving the kevlar thread in a Z-pattern through the hopper columns, so the PPBs would not fall out of the sides of the hopper once it was raised out of the slot. This Z-pattern keeps the columns from spreading too far apart. We secured the scissor arms to the scissor arm base that is screwed on to the hopper top with two of our scissor arm axles. The caps on the pins were interfering with the retraction of the scissor arms, so we had to cut out small notches in the scissor arm base with the mill to allow the scissor arms to retract more completely. We put washers on the pins in the scissor arm base to keep the two ends of the scissor arms from sliding to the opposite side from where they are supposed to be. We demonstrated our MCM for MS8 in the slot, and we realized that we also need to have something constraining the hopper columns from compressing toward eachother. We decided to add spring steel to the sides of the hopper to reinforce it.

We cut the cart bases to length out of the square tube stock, using the band saw, and we drilled holes in them using the drill press. We also used the drill press to finish drilling holes in the L-connectors.

We cut the brackets that will be holding up the leadscrew with the band saw, out of the aluminum 1/2" square stock. We then went to the mill with these brackets and started the process of tapping holes in them in order to secure them to the cart top with a screw. We are using the #8-32 screw, so we used the #29 screw (from the drill/tap chart), and we drilled holes in them. We then took these brackets to the tap, and used the #8-32 tap.

Next week we will have to finish manufacturing and assembling the leadscrew module, turn the wheel axles and couple them to the wheels, and couple the motors to the leadscrew and wheels.