Q&A

[aubrey048]

If anyone has some hints for those of us with almost no prior electrical engineering experience whatsoever, please post them here. We would greatly appreciate any Mission Possible building advice!

[Primate]

There's really nothing to it. Assuming you know absolutely nothing about electricity, here's the basics:

• In order to get electricity to flow, you need a circuit. This circuit must contain a battery and a load, like a motor or light. Basically, you stick a wire from the one end of the battery to one end of the motor or lightbulb, and another wire from the other end of the load to the other end of the battery. Voila! Electricity!
• For Mission Possible, you'll have to trigger most of the circuits with a switch. This could be a storebought pushbutton switch you wire into your circuit, or something you rig up yourself. As an example, we wired up a mousetrap in our project. We attached a wire to the spring, and then wired up a metal plate where the cheese usually goes. When the mousetrap snapped, the two pieces of metal touched and completed the circuit.
• Learn to solder. This is the best way to make permanent electrical connections. Other techniques, such as alligator clips and just twisting wires together, have a tendency to fall apart.
• Don't use tape. Screw everything together. The one little thing we taped failed at invitationals.

I'm sure there's plenty of other tips and tricks other people will have for you, but that should be enough to get you started.

[Sir_L_Jenkins]

Make sure you don't send too much voltage through that metal wire you use to melt fishing line...I was stupid and tested it on a 12 volt and it snapped and half and burned spectacularly, however there's a huge burned gash in our alligator clips, and it definitely could have done some uber damage if it actually hit our skin...

Different thicknesses of wire require different voltage, but just don't be stupid and put way more than needed....=P

[zcshiner]

This should go without saying, but match voltages carefully.

If you have a 3volt led, do not hook it up to 9volts. Same things with relays and motors. They will burn out fast.

[Flavorflav]

This should go without saying, but match voltages carefully.

If you have a 3volt led, do not hook it up to 9volts. Same things with relays and motors. They will burn out fast.

It should go without saying, but apparently it doesn't. Somebody did exactly that to our LED setup last night, then brought it to me to ask what that burning smell was.

[Sir_L_Jenkins]

Hmm, so, impound question:
When we impound our device, does everything have to be within the 50x50x80 specifications, or does it only have to be that way right before the run? I ask this because our flagpole is spring loaded, and I would prefer not to keep it "armed" between impound and competition. Also, we usually bring a spare parts box with us, with things like batteries, balloons, etc, that wouldn't be in our 50x50x80 box, but rather impounded beside it. So, I'm not sure whether the judges would permit this, any thoughts?

[Dark Sabre]

It doesn't have to be in run-configuration when you impound it. It can exceed dimensions during impound, those are just measured prior to the run.

Yes, spare parts boxes/tools are okay.

[bridgebuilder25]

When it says teams may "adjust" the device during testing, may competitors use an object other then their hands to touch the device and allow operation to continue? (Such as poking the balloon with a pin in case it fails to pop)

[Uncle Fester]

I think you're confusing a few things here. Also not sure if your asking if you CAN touch with an object means "at all" or "without getting the penalty". Gotta love the English language! To answer, I'l respond to both.

"Testing" refers to fine-tuning your device before you RUN your machine for points. You can mess with your device all you want. If you go over 30 minutes of setup time, you neither get DQ'ed or halted-- you can keep setting up but you lose a rather hefty bonus.

However, if you touch your device WITH ANYTHING during your points-earning (hopefully) run, it's a touch. Some event sups assess the penalty at every muscle contraction, some a lot less. I'm in the last group; if you touch something, It's ONE penalty until you either touch another STEP or pull your hands out and reach back in. This is why I tell everyone right before their run starts, , "Keep at least one hand in until you're sure it works." I do this with everyone, even the ones I see four times a season, since event sups differ on this. Me, I don't run a "penalty mill" or "DQ fest."

If I had my way (haven't for quite a while), I'd eliminate most touch penalties-- score more points for working stuff, half credit for anything that ran WITH touching, and no credit where touching didn't fix it. No credit for bypassed steps. Assess serious touch penalties where running stuff got touched (fixing something on the run, or ahead of time).

[bridgebuilder25]

I was referring to a touch during demonstration for the judges. Though I know touching is a penalty, I wasn't sure if you would get DQ'ed or something if you touched the device with something other then your hands.