General Questions

[Balsa Man]

Make sure it is legal and reliable (no touches). A flagpole attached to a mousetrap got 7th at our regional because it had no penalties and got the completion bonus. As Paradox said, forget the photocell - make a motor move a mass for 40 seconds. It's not that hard to do and worth 135 points (25 for the task, 30 for the bonus, and 80 for coming closer to the ideal time). That's more than five times as much as any other component. Also, make sure your TSL is accurate and you don't go over time on the setup - that's another 150 points between them. If you have time, the golf ball and electromagnet aren't that hard, but you could probably medal in some regions with just the mousetrap, motor and flagpole.

Good analysis; good advice. Balloon pop is pretty straightforward, too.... Motor moving a mass is probably the easiest way to both the 40 sec points and getting timing close to target time.

[bridgebuilder25]

I had a question about one of the tasks. For task 4g, it states that you must raise a golf ball by a vertical distance of at least 30 cm, and its new position must lead to the next action. Can the golf ball be raised 30 cm, and then drop down and cause the next action? Or must the next task be triggered while the golf ball is 30 cm higher than its starting position? Thanks guys!

[Primate]

I had a question about one of the tasks. For task 4g, it states that you must raise a golf ball by a vertical distance of at least 30 cm, and its new position must lead to the next action. Can the golf ball be raised 30 cm, and then drop down and cause the next action? Or must the next task be triggered while the golf ball is 30 cm higher than its starting position? Thanks guys!

I would say that the "new position" would imply the raised position. If you drop it back down, it essentially hasn't moved at all. I'd agree the rules are a bit vague, but I'd be on the safe side and just have it trigger once it raises.

In my design, we put the golf ball in a PVC tube that was slightly larger, and made a simple housing to raise the ball with a string and a motor. Then, at the top, we just mounted a microswitch that's weak enough to be triggered by the golf ball. Works perfectly, if that gives you any ideas.

[Hedgehog325]

Does anyone know if the the balloon used has to be a standard balloon? Am I allowed to use a water balloon in its place? Technically, It's still a balloon.

[Paradox21]

Does anyone know if the the balloon used has to be a standard balloon? Am I allowed to use a water balloon in its place? Technically, It's still a balloon.

Water balloons are fine and probably a better idea. They are small and aren't as likely to produce shards of balloon that a picky judge could call uncontrolled projectiles.

[Primate]

Does anyone know if the the balloon used has to be a standard balloon? Am I allowed to use a water balloon in its place? Technically, It's still a balloon.

Water balloons are fine and probably a better idea. They are small and aren't as likely to produce shards of balloon that a picky judge could call uncontrolled projectiles.

I haven't experimented with water balloons myself, since I was concerned they might be a little harder to pop because they're manufactured to withstand greater impacts than your standard helium balloon. Does anyone know if this actually holds true?

[Uncle Fester]

Collection of comments here.

I think that the water balloon idea is just asking for trouble. As mentioned before, they're tougher and harder to break; plus, you now have water that might cause issues.

Again, someone lauded the overrated 9v battery.I've been keeping track, and I'm well past the 100 mark for failed tasks involving 9V batteries-- I stopped counting last weekend.

Devices with successful photocell steps are now appearing more often than now; my estimate is 60% or more. And they work. And the teams that have them beat the teams that don't, simply because if they can do the photocell, they can do everything else. I've had four perfect machines so far.

The question about an up-and-then-down golf ball lift was interesting. I think I understand the idea: perhaps raise a ball 30cm, have it roll off the top of the lifter, and drop down a bit on an alternate route until it hits something, like a switch. However, I'm inclined to say "no", simply because of the afore-mentioned POSITION of the lifted golf ball, etc. I >>DO<< suggest your coach send it in to NSO for a clarification, if not for an answer, but to pass along the idea that rules need to be written to cover possibilities, and not just steer people to a "suggested" solution.

Final thought: contrary to dire warnings by many (including myself, Mr. Egg-On-The Face) taht there was no room for variety and that all devices would look the same. . . BALONEY. There's an incredible variety, from the simplest start task to the photocell bonus.

[Flavorflav]

Collection of comments here.

I think that the water balloon idea is just asking for trouble. As mentioned before, they're tougher and harder to break; plus, you now have water that might cause issues.

I don't think he meant a balloon with water in it, but one sold as a water balloon that he would fill with air.

BTW, do you think a motor that unspooled a string, lowering a mass on to a switch, would count as "continuously moving a mass" under 4c?

[Balsa Man]

BTW, do you think a motor that unspooled a string, lowering a mass on to a switch, would count as "continuously moving a mass" under 4c?

I think that's gotta be yes. Rule says "move a mass" - doesn't say "up", or "down", ....or sideways. If its continuously going down, that's moving.

The moror moving a mass is, as most of you have probably figured out, the prime candidate for the timing step this year. You get points up to 40 seconds, so that's 2/3 of Regional ideal time. You want your timing step to be as big a percentage of total time as possible. The shorter the other steps are, the less impact on time variability they'll have- a 10% variability in a one second step is only a tenth - that same variability in a 10 second step is a full second.... Multiply individual step variability times 9 other steps......
And you want your timing step to be reliable, consistent, and easily adjusted in small increments. A motor, geared down (those Tamaya gerbox & motor units at the local hobby store....), winding a fine string around the shaft gives you, oh, 1/2 to close to 1cm per second, and a microswitch with a screw position adjustment makes it easy to move the switch around, precisely, within that one second.

Regionals tomorrow. If it goes as it has gone in testing, they'll be within a tenth of 60.5 sec.

[Flavorflav]

BTW, do you think a motor that unspooled a string, lowering a mass on to a switch, would count as "continuously moving a mass" under 4c?

I think that's gotta be yes. Rule says "move a mass" - doesn't say "up", or "down", ....or sideways. If its continuously going down, that's moving.

That's the way I ruled when it came up. My only hesitation is that one could say that technically gravity is moving the mass and the motor is acting as a brake.