Thoughts on fans

[Jkwashbourne]

It seems like a fan would have to count as one of the three allowed motors. But with the moving air task (4c), I was wondering if fans would be allowed not counted as motors. TIA.

[Schrodingerscat]

It seems like a fan would have to count as one of the three allowed motors. But with the moving air task (4c), I was wondering if fans would be allowed not counted as motors. TIA.

My personal judgement (caveat: I have not read the rules for this event) would be that if a rule does say the device may only contain three motors, a motor contained inside a product (such as a motor in a commercially available electric fan) would be considered a motor. I would strongly recommending making design chances to your device to avoid this problem, as unless an official clarification is issued in your favor, it would be far too risky in my own personal opinion.

[alpacas]

If you are set on using a fan, you could attach it to a spool and spin it as string begin pulled unwinds the spool

[SALIA]

where can I buy the motors and how can I turn on/off the motors. Please shed some light...

[hogger]

where can I buy the motors and how can I turn on/off the motors. Please shed some light...

You can buy motor from ebay or radioshack. Look for DC motor with voltage around or less than 12V (you can drive a 12V motor with 10V battery, it still works). You don't need high RPM (revolution per minute) motor, something in the few hundreds RPM will do depending how much force/speed you want from your fan. Then you need a DC switch or a simple two conducting metal surfaces that can come in contacts to make a connection, or a separation of the metal surfaces to disconnect the electrical path. Attach the metal surfaces to the wires and connect the wires to the battery terminals and the motor terminals in a loop (closed circuit).

Another way is to do it without a motor. Go talk to the kids on your team that are doing helicopter and ask them how to make rubber powered propeller that you can attach to your device. Then you just need to figure out how to hold the propeller attached to the wound rubber and release it when you need to start the task.

PS: another good source for motor is an old broken ink jet printer. There are usually one or two good DC motors in there. It takes some effort to take it apart but if you have a broken one lying around, it is free.

[goodcheer]

where can I buy the motors and how can I turn on/off the motors. Please shed some light...

Battery powered toys like old cars, cordless screwdrivers, etc. etc. Take the old devices apart, being careful not to disturb the two main wires coming from the motors. Many times it is best to keep part of the housing for the motor so you can mount it in your device easily. It might also have a gear-box connected to the motor which can be useful. Lever-style switches are good and are easy to use in mission possible. A falling mass can land on a switch to turn on a motor and when the action is completed another switch can be activated to turn off the motor. However, you don't have to have a second switch to turn off the motor as long as it can continue to run without disturbing any further steps.