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chalker7 wrote:

chalker wrote:

fishman100 wrote:My friend's brother did bottle rocket (apparently his brother is in ESO, but IDK if that was an event in ESO) with a 1-liter bottle...he said the bottles were extremely hard to find. But I'm looking forward to seeing everyone's designs at competitions!

That's a concern I had too (but was overruled on). Supposedly they are pretty common in gas station convenience stores.

Every grocery store in the country has 1L carbonated bottles, but they might not be in the soda aisle. Carbonated flavored water, club soda and tonic water are all most commonly sold in 1L bottles and are generally stocked with the other bottled water, near the sports drinks and energy drinks.

There is actually much more variety in 1L bottle shapes than 2L, which could lead to interesting designs.

YUP, Ive gone to Grocery Stores and Conveience Stores and there are TONS of 1L bottles, they are mostly all the same design as the 20oz Bottles, but look a little bigger

chalker7 wrote:

chalker wrote:

fishman100 wrote:My friend's brother did bottle rocket (apparently his brother is in ESO, but IDK if that was an event in ESO) with a 1-liter bottle...he said the bottles were extremely hard to find. But I'm looking forward to seeing everyone's designs at competitions!

That's a concern I had too (but was overruled on). Supposedly they are pretty common in gas station convenience stores.

Every grocery store in the country has 1L carbonated bottles, but they might not be in the soda aisle. Carbonated flavored water, club soda and tonic water are all most commonly sold in 1L bottles and are generally stocked with the other bottled water, near the sports drinks and energy drinks.

There is actually much more variety in 1L bottle shapes than 2L, which could lead to interesting designs.

Some gas stations sell 1L pop bottles that are shaped like 2L.

chalker wrote:

fishman100 wrote:My friend's brother did bottle rocket (apparently his brother is in ESO, but IDK if that was an event in ESO) with a 1-liter bottle...he said the bottles were extremely hard to find. But I'm looking forward to seeing everyone's designs at competitions!

That's a concern I had too (but was overruled on). Supposedly they are pretty common in gas station convenience stores.

Ah, so it's not a typo.
If I have something attached to my rocket by string, does this violate the rule of "not changing shape?"

Asbestoast wrote:

chalker wrote:

fishman100 wrote:My friend's brother did bottle rocket (apparently his brother is in ESO, but IDK if that was an event in ESO) with a 1-liter bottle...he said the bottles were extremely hard to find. But I'm looking forward to seeing everyone's designs at competitions!

That's a concern I had too (but was overruled on). Supposedly they are pretty common in gas station convenience stores.

Ah, so it's not a typo.
If I have something attached to my rocket by string, does this violate the rule of "not changing shape?"

Depends...if the string was deployed during the flight then yes it would but if you just had the string randomly attached to the bottle before/during the flight then no.

i have a question is it a violation to have the fins of the rocket to be iverted

dspearman wrote:i have a question is it a violation to have the fins of the rocket to be iverted

Nope...in fact angled fins (even if they're at a 90 degree angle) might help you.

So, 1 liter bottles this year. I wonder if a design in the plastic of the bottle would give an advantage over a bottle with no design at all.

That would be an interesting variable to test. It would also be an easy thing to do, just get 5 or so different bottles and shoot them into the air. From past experience it seems that the rocket design is more important then the bottle choice as long as the bottle fits on the launcher.

I'm trying to decide between getting the Pitsco AquaPort and the NERDS Ultimate Water Rocket Launch Pad. It seems like both have been used in Science Olympiad events. Does anyone have any opinions on which of these is better? The Aquaport is $139 and the Nerds one is $119 so while both pricey, the difference isn't that significant. Is the PVC tripod (aquaport) better than the aluminum block style?

Here's the Pitsco: http://shop.pitsco.com/store/detail.aspx?ID=1179
Here's the NERDS: http://www.nerdsinc.com/Products?category=1

My son is trying to start with the bottle rocket competition this year (6th grade in NY) so I'd like to get one of these for him to learn by experimenting at home. I'd consider making one myself, but I imagine he'll be doing this with a bunch of his friends and prefer to have the safety and reliability of a well established commercial launcher.

Thanks!

gmui wrote:I'm trying to decide between getting the Pitsco AquaPort and the NERDS Ultimate Water Rocket Launch Pad. It seems like both have been used in Science Olympiad events. Does anyone have any opinions on which of these is better? The Aquaport is $139 and the Nerds one is $119 so while both pricey, the difference isn't that significant. Is the PVC tripod (aquaport) better than the aluminum block style?

Here's the Pitsco: http://shop.pitsco.com/store/detail.aspx?ID=1179
Here's the NERDS: http://www.nerdsinc.com/Products?category=1

My son is trying to start with the bottle rocket competition this year (6th grade in NY) so I'd like to get one of these for him to learn by experimenting at home. I'd consider making one myself, but I imagine he'll be doing this with a bunch of his friends and prefer to have the safety and reliability of a well established commercial launcher.

Thanks!

I used both last year and I found that the Aquaport was better. First off, the NERDS launcher has a stake that connects the launcher to the ground, so if you're planning to test on a hard surface (asphalt, for example) you might have trouble pinning it to the ground. (We encountered this problem while testing in the middle of a parking lot and tried to weigh it down with the extra water bottles we had, but the launcher still managed to slide when we tried to pull it. Our solution was to have my partner stand on the edge of the launcher while I pulled the rope. He got soaked.) I also noticed that you have to exert more strength to launch the bottle.

Now, one advantage of using the NERDS launcher is that you might get more accurate results. I don't really know how to explain this (partially because I was more focused on the building aspect of the event rather than the physics) but if you have a longer nozzle to launch the rocket then the flight time will be extended than if you have a shorter nozzle. The nozzle of the NERDS launcher pretty much fits exactly on the mouth of the bottle with little room to spare, which we found extremely helpful in the long run.

In the 4 competitions I've been to while having BR as an event I've seen the Aquaport launcher used the most, including at last year's National Tournament. The Aquaport is a tripod which makes it very easy to assemble/disassemble but it took a lot of effort to make sure the 3 legs were the same length (because our rocket was very reactive to a non-level launch surface). Unlike the NERDS launcher the Aquaport doesn't slip and slide around, but that's mainly due to the stake.

There's a special plug that fits onto the top of a tube for the Aquaport that allows the air to enter the pressure chamber. When we bought the Aquaport 2 plugs (of different sizes) were included but when we got to a competition that used the Aquaport they only had the other plug. We were still able to launch our rockets but the rockets didn't fit onto the rockets very easily, so if you do plan on testing with the Aquaport make sure you have both plugs at competitions.

When we started BR we originally built our own launcher, but compared to the other manufactured launchers (such as the NERDS or Aquaport) it sucked. We ditched the homemade launcher after a few weeks and I don't think we used it again. I can't really say whether the rocket's lights would have been any better/worse because at the time we were launching empty 2 liter bottles to familiarize ourselves with the event.

Regarding safety: I suppose the manufactured launchers would be the safest, however our homemade one was as safe as the Aquaport/NERDS (aka it doesn't really matter which one you pick in terms of safety). A homemade launcher can be dangerous if built incorrectly, especially when it comes to sealing any gaps that could potentially blow off an entire section of the launcher. One time our rocket launched itself prematurely while I was pumping and that caught everyone off guard (but that was another launcher so I guess it's not that big of a deal). Safety-wise both the Aquaport/NERDS are very safe, however, I would consider the Aquaport to be a little more safer since it has a pin you can insert to prevent any premature launches.

My recommendation would be to use the Aquaport. Yes, it's more expensive but since your son competes in a VERY competitive state chances are the state (or your school) already has one that he and his partner can use for testing. Since our team won states that year a school actually loaned us their launcher until the end of Nats. That was a nice gesture and I'm sure some schools in NY would be willing to do the same.