2010 Paradox21 MPC

Articles in this series

The following is a list of pages pertaining to Mission Possible for Division C. Some of these pages may contain outdated information.

• Main Article
• Documented Devices
  • 2004 DarkSabre MPC
  • 2005 DarkSabre MPC
    • A guide to programming with Lego Mindstorms and NXT
  • 2010 Paradox21 MPC
  • 2018 Davecutting MPC
  • 2018 FHC MPC
• Useful Components
  • Thermal Devices
  • Optical Devices
  • Mechanical Devices
  • Electrical Devices
  • Chemical Devices
• Year-Specific Information
  • 2018 Tasks
  • 2019 Tasks

This is Paradox21's Energy Transfer List (ETL) from Nats 2010. Added on are two columns (Picture and Description) to help explain what is going on.

Note that the rules for the ETL have changed every year and the below should not be considered an example for whatever the current rules are.

The machine placed 8th at the 2010 National competition.

Step	Latter/Action	Picture	Description
1	a. Starting Task - Drop golf ball on mousetrap to activate it		The mousetrap was a trap that only rotated 90 degrees and automatically set itself when it was pushed back. The golf ball went through the PVC pipe and rolled to the right once the trap was triggered. There is a door to remove the ball.
2	f. Mousetrap activates hydraulics system that activates light bulb		The mousetrap pulled the syringes upward and triggered a microswitch on the bottom of the hydraulic rig. I found the two smallest syringes and connected them with about a centimeter of tightly fitting aquarium tubing.
3	b. Light bulb activates photo cell which powers motor		This step required the most tinkering. I hooked up a flashlight head to 2 AA batteries and ran 6 D batteries through 4 photoresistors hooked up in parallel that I bought from RadioShack. I tried several motors and settled on the one that turned the easiest in the rig. Even with that motor, it barely had enough force to trigger the next switch.
4	d. Motor deactivates electromagnet which drops a ball bearing		I used a normally closed on-off switch that I found at a surplus store to power my electromagnet. I had to add washers to the switch to make it easier for the motor to trigger. I made the electromagnet by wrapping magnet wire (RadioShack) around a nail with a drill. When deactivated, a ball bearing fell onto a lever which tipped over to trigger a switch. That switch was also weighted with washers. The elecrtomagnet was powered by 4 AA batteries.
5	g. Ball bearing trips switch which turns on motor that raises golf ball over 30cm		The golf ball was inside a little box with 2 eye hooks to prevent the box from twisting. The motor ran through the normally closed side of the switch it was triggering, so it shut off as soon as the next transfer was triggered. Because of the gearing on the motor, the box did not fall back down once the power to the motor was cut.
6	i. Golf ball triggers switch which turns on fan which blows out balls		I chopped up the housing for a k'nex Big Air ball Tower motor. It had a fan inside that blew out 2 balls which fell down the PVC tube and triggered a switch.
7	e. Ball triggers switch which turns on nichrome wire which melts fishing line which drops weight		I stapled a chunk of nichrome wire from a toaster into a piece of wood so I didn't melt my legos. The fishing line was held in place on both sides of the wire with legos which made it very easy to replace. When melted, the fishing line dropped the end of a flashlight that was filled with washers onto a switch. The switch activated a relay that diverted the power for the nichrome wire to the balloon pop.
8	h. Weight triggers microswitch which turns on motor that pops balloon which allows a lever to fall		I inflated a small party balloon (more like a water balloon). I attached a bulldog clip with a thin piece of wood glued on both sides to stop the air from escaping. The balloon was placed under the lever so that the lever was parallel with the ground. Then the relay tripped, a big motor with a little pin popped the balloon. The lever had a spring attached above it on the opposite side. This pulled the lever into the next switch. The motor was wired through the normally open part of the switch it was triggering, so the power cut off once the lever tripped the switch. There was also a little drape I put over the balloon during runs so no balloon shards would fly out.
9	c. Lever triggers switch which activates motor which turns threaded rod for more than 40 seconds		The threaded rod was the variable timing portion of the device. I hooked up a Lego Mindstorm NXT and ran the rod backwards for a set amount of time. Then the NXT was removed for the actual run of the device. My biggest trouble with this was the batteries. The motor ran on 2 AA batteries and I ended up grouping batteries of similar voltage. When the rod ran in, it triggered a relay which diverted voltage from the threaded rod over to a small motor to trigger the flag.
10	j. Final Task - Wingnut hits switch which diverts power to motor which triggers mousetrap which raises flag		The flag was hooked up to the same kind of mousetrap in the starting step. The motor triggered the mousetrap which raised the flag. As it triggered the mousetrap, it simultaneously triggered its own kill switch. This switch was the same normally open on-off switch I used for my electromagnet. This prevented the motor from continuing to run after it had triggered the trap. The syringe was added to slow the flagpole just enough to prevent it from hitting the side and bouncing.