We held our first drag racer competion this year.
Students built drag racers from PVC pipes and raced.
Design
Cooperation and Communication
Wheel Friction
Weight of Drag Racer
What to do with a 50 foot cable
Allowed grades 2-5 to compete.
Grades 6+ take part in Sea Perch
High school and Junior high students ran the program and did all wiring, cutting, and drilling
Each grade level was given 2 work days
Work days were 1 hour each.
We competed in front of the whole elementary in 1 hour
Grades 2 and 3 were more comfortable jumping in and starting; willing to fail forward
Grades 4 and 5 worked slower; wanted to discuss more, they wanted to get it right the first time, no failing forward
2 days worked for 2nd and 3rd grade, older grades could use more time
Competition was too long for whole group
Smaller group competition
Have grade level viewing
svROV DRAG RACERS can be done in a class environment!
No budget sheet for younger grades
Increase work day by 15 minutes to allow time for reflection and journals
Student "costs"
Each team has an imaginary $20 to spend and account for:
1. Pipe Costs $0.10 per Inch - PVC, cPVC, 3d Print are all the same cost per inch
2. PVC Elbows and T's $0.10 each
3. Wheels cost $1.00 and
Motors will cost $1.00 each - Max on Racer = 2
4. Quick Connects cost $0.50 Each
5. Rental of Controller and Cat-5 Cable $3, one time fee.
6. Zip Ties $0.25 each
7. Additional purchases are independent of svROV build list and have Real Dollar amounts.
Teams must keep a log of their building activity and cost.
1. Course is 20 feet long.
2. Timed Distance to 20 Feet finish Line.
2018, TBD
Battery: Get something similar to this
Jameco Electronics -
Push Button Switch $3.49 Each Item # 121305. (ct 2 per controller)
12 V motor $2.95 Item Number #232022 (ct 2 per Drag Racer)
Amazon:
Quick Connects $11.95
Cat-5 Cable 100' $5.15
Wheels, bag of 100 $19.57
McMaster Carr
Tee-Nut Insert (100)
LockNut (100)
Alligator Clips 1 per controller
Transparent Speaker Wire that goes from battery to controller, cut into 5' sections
Tower Hobbies
Item # L5K08912
Threaded Coupler 4-40 - 1 package per Racer + Spares
Controllers can be made in boxes like this
Toggle Switches or push buttons (2) would control individual motors
Cables can be wired to the quick connects to attach the motors to the controller
The other end of the cable would be "hard-wired" into the controller. - (see folder below)
A set of wires would exit the controller and have alligator clips attached. This would attach to the battery.
Fuse and fuse holder would be placed near battery
Drawing for Controller Wiring (see folder below)
I would have 2-3 controllers made for everyone to share and use.
Wheels can be assembled by students.
Place Tee-Nut Insert on Threaded Coupler
Place Wheel on threaded coupler
Place Lock Nut on to hold the wheel in place.
Threaded coupler is superglued to 12 V motor
ROV frame is made with PVC pipe, T's and Elbows from local hardware
PVC Pipe cutter are necessary. Have students measure and mark before the cut. Anyone under 12 should cut by themselves.
12 v motors and wheels are placed on ROV frame - Using Zip ties
Optional: Holes can be drilled into PVC for wheels and zip-ties, but not necessary.
Quick connects attached to ROV motors to allow quick and easy storage without giving every group 30 feet of cable.
Make sure all male ends are on Motors and all female ends are on Cat-5 (or vice versa)
Pliers or small vice grips
Nut Drivers 1/4"
PVC Pipe Cutters