WRA2 wrote:Any kind of "open" class would cause the competition to turn into a "who has the most money" competition. How would that achieve making the competition accessible to someone who does not have access to advanced manufacturing techniques or a factory? When the competitions were designed almost 15 years ago, much thought went into preventing teams from using "advanced manufacturing" to construct the rockets.
Class A (and others) are already "open" with some restrictions. I'm just calling a spade a spade here, and I haven't proposed removing the current restrictions. By "open" I meant the class is open to using advanced composite fabrication techniques that are out of reach for the vast majority of potential competitors.
Within the 1.5 kg weight limit, there is no limit on volume or pressure. Basically the class is accessible to the organization who can fabricate (from scratch) the highest-pressure lightest-weight pressure possible. The restriction is on using parts manufactured for rocketry, but manufacturing your own parts from scratch is still allowed (this was clarified in a 3-D printing thread I started a while back). Just look at the current class A record holder. Their documentary on Ascension III is available on YouTube. There is no evidence of a soda bottle or even a FT sleeve being used there. That rocket uses machined parts and a carbon-fiber filament body and pressure vessel. Yes it was built from scratch... using advanced composite fabrication techniques. It's an amazing accomplishment, but it underscores my original point.
So I proposed that class A could have categories that include the current "open" definition as currently defined, as well as some unreinforced pressure vessel categories (single and spliced bottles).
There is also nothing that says you cannot use bottles for the class A or B competitions.
No, of course not. My point was that there's also nothing that says you must
use bottles either. That is why I proposed a category for bottles in each class.
For the class B, this competition class was created for multiple stage rockets because a multiple stage rocket will never beat a single stage (and meet the weight requirement).
Yes, I realize that. Nowhere did I propose eliminating or merging this class. I agree it should be separate for the reason you stated. I proposed to have categories within the class. My point remains, that using a scratch-built filament-wound carbon-fiber pressure vessel is a totally different category of rocket than using an unreinforced bottle or FT sleeve. Currently class B has no pressure restriction, making this class "open" to advanced composite fabrication techniques unavailable to the vast majority of participants.
The class "C" flight duration competition a "class A rocket" with a large chute" would be ineligible. The class was created as our ultra low cost (using unreinforced and unmodified bottles) and a manual pump for pressurization with no onboard camera requirement).
Ah, you're right. I was looking at the "pressure vessel rules" in class C and found no requirement to use a bottle there. I see now it's in the first section. My statement is still valid if you replace A with D: wouldn't the class D record holder with a large parachute also be the winner for class C? Parachute mass is almost negligible. Given a large parachute, the determining factor for the record would be altitude.
I am actually surprised that no one has attempted the reinforced bottle competition. You would think that someone would wrap a bottle with fiberglass and claim it.
I am not surprised, and I explained why in the post I referenced earlier
. Sure, I could wrap a bottle in fiberglass. If that bottle can now withstand, say, 300 psi, I'd have to invest in a specialized air compressor and new hoses and fittings, because a foot-pump and metal fittings bonded to PVC won't work. After investing all that money and time to hobby-wrap a bottle in fiberglass, a company with resources, such as US Water Rockets (who abstained by the way) could get involved and submit a precision filament-wound carbon-fiber bottle. So why should I bother, knowing that someone with comparitively unlimited resources can come along and beat my hard work? That's why there are no takers.
In the past there were competitors who campaigned for more classes (usually it would turn out that they had given a great deal of thought to crafting the competition such that they had a particular advantage. There is even one guy who is attempting to get pyro certification in an attempt to circumnavigate the weight requirement.
I hope it's clear that my proposal is designed to open up competitions to more people who have less resources. WRA has members in several countries with highly creative people who cannot afford advanced fabrication equipment.
Having too many classes also dilutes the competition field as well.
I agree. You'll notice I actually proposed reducing the number of classes by merging class D into a category of class A. The whole idea here is to have a logical set of classes that clearly separate the teams with vast fabrication resources at their disposal from those who are building rockets using unreinforced bottles.
You seem to have the impression about the class A and B competitions only being accessible for people with access to advanced manufacturing. Do you have any suggestions on how section I.4 can be rewritten so that people will not get that impression?
I got that impression simply by looking at the class A winner. Look at the Ascension III documentary
on YouTube. Machined parts, composite materials everywhere. That can't be beaten by unreinforced bottles.