Bottle Rocket B

[Zioly]

Am I missing a drawback that makes them unpopular?

-NeBH

They provide less drag on the descent. Just out of curiosity, what times have you been getting at 60 psi, NeBH?

Thanks, Zioly!

Unfortunately, my launcher has a pressure release valve that blows at ~50 psi, so I haven't been able to test at 60. Also, it was meant for 2 L bottles.
The manufacturer said that it "doesn't work as well" with 1 L, which I think (after you translate from lawyer-eze to experience-landic, of course) means

"After you work out your

air pressure issues (Click to Show Hidden Text)

There's an adapter that goes from the air hose on the compressor to the launcher. Well, we lost it. So I asked my mom to buy a new one. She did, but we opted for the cheap one. Guess what! It was leaky! Of course, I didn't realize that until I'd spent a few days struggling with the little booger...
So, I asked her to get another one (not the cheapest one this time). So we did that. I put that one together, and tried to use it. That one leaked too! Turns out, I was learning the difference between normal threads and pipe threads (i.e., you can tighten normal threads quite a bit before they break. But pipe threads...). Then, after all that, I found our other adapter (that actually works) underneath some sandpaper. Just lying there. :evil:

,the bottle gets stuck on the launcher! Obviously, you will get fairly wet when you do get the little booger off. Then, you try putting some oil on the launch tube. But that makes it even worse! Now it comes off while you're still pressurizing!"

Then, I ran out of time, and decided to focus mainly on my best event. Sorry for the rant... Anyway, I think I got about 10 seconds (total) at the competition. But I could be off by +/- 5 s.

I'm completly sorry I didn't see this earlier. I believe I can help you a lot. (Click to Show Hidden Text)

For the bottle scratches, I believe that anything that might possibly comprimise the structual integrity of the bottle can be called out by the judge, and possibly get you DQed.
But on the other hand, it's difficult to replicate rocket results when you switch bottles. This is really a question up to decide on. Would you call out the bottle because of the scratch? or do you think that a scratch could weaken the bottle? if so, then I suggest that you replace your bottle with an Identical bottle, but make sure that you practice with this new bottle if you change it. 

For the labels, I think all judges look for is the "Carbonated Beverage" label, and sometimes a rough corrolation between bottle and label. What I mean, is that they can see if you used a 2 liter coke label for a 1 liter bottle and so on so forth.

If you are using duct tape to attach fins, I suggest that you use the least amount possible, or switch to packaging tape. Attaching fins is really the only place where you should use duct tape. If you have it anywhere else on the rocket, you should switch to packaging tape for weight reduction. If you can, even try packaging tape on the fins, but test to see if it's strong enough to hold them in place before you compete. 
The materials you use on your fins seems a bit iffy though. Balsa is a bad material for rockets in general, and I'm glad you noticed that. Foam board might work, but I have a better, weight friendly solution you should maybe check out. I suggest you get Corrugated Plastic boards, and 0.007 inch plastic film to make a sort of hybrid material fin design. 

My design consists of a Trapezoid shaped fin, made out of a parallelogram shaped piece of corrugated plastic in the front (make sure the holes are parallel to the leading edge) 
and a triangle of flimsy plastic film on the back. The film is pulled taut from being taped between the bottle and the corrugated plastic leading edge. once you have this down, I would pinch the front of the corrugated plastic into a point for better aerodynamics (hence why I suggest that the holes be parallel to the leading edge.) Then tape this onto the bottle. 

since I don't know the overall design of your rocket, I suggest that you play around with this design, and work out which variation of this design works best on your rocket. 

Good luck at nationals, and happy flying!

Thanks, Fanglin! That helps a lot!
I'm not sure I understand your fin design, though.
Would you mind posting a picture of it?

-NeBH

Ouch! All of those launcher troubles sound tough! Are you using a cone or a T8 tube?

[NeBH]

They provide less drag on the descent. Just out of curiosity, what times have you been getting at 60 psi, NeBH?

Thanks, Zioly!

Unfortunately, my launcher has a pressure release valve that blows at ~50 psi, so I haven't been able to test at 60. Also, it was meant for 2 L bottles.
The manufacturer said that it "doesn't work as well" with 1 L, which I think (after you translate from lawyer-eze to experience-landic, of course) means

"After you work out your

air pressure issues (Click to Show Hidden Text)

There's an adapter that goes from the air hose on the compressor to the launcher. Well, we lost it. So I asked my mom to buy a new one. She did, but we opted for the cheap one. Guess what! It was leaky! Of course, I didn't realize that until I'd spent a few days struggling with the little booger...
So, I asked her to get another one (not the cheapest one this time). So we did that. I put that one together, and tried to use it. That one leaked too! Turns out, I was learning the difference between normal threads and pipe threads (i.e., you can tighten normal threads quite a bit before they break. But pipe threads...). Then, after all that, I found our other adapter (that actually works) underneath some sandpaper. Just lying there. :evil:

,the bottle gets stuck on the launcher! Obviously, you will get fairly wet when you do get the little booger off. Then, you try putting some oil on the launch tube. But that makes it even worse! Now it comes off while you're still pressurizing!"

Then, I ran out of time, and decided to focus mainly on my best event. Sorry for the rant... Anyway, I think I got about 10 seconds (total) at the competition. But I could be off by +/- 5 s.

I'm completly sorry I didn't see this earlier. I believe I can help you a lot. (Click to Show Hidden Text)

For the bottle scratches, I believe that anything that might possibly comprimise the structual integrity of the bottle can be called out by the judge, and possibly get you DQed.
But on the other hand, it's difficult to replicate rocket results when you switch bottles. This is really a question up to decide on. Would you call out the bottle because of the scratch? or do you think that a scratch could weaken the bottle? if so, then I suggest that you replace your bottle with an Identical bottle, but make sure that you practice with this new bottle if you change it. 

For the labels, I think all judges look for is the "Carbonated Beverage" label, and sometimes a rough corrolation between bottle and label. What I mean, is that they can see if you used a 2 liter coke label for a 1 liter bottle and so on so forth.

If you are using duct tape to attach fins, I suggest that you use the least amount possible, or switch to packaging tape. Attaching fins is really the only place where you should use duct tape. If you have it anywhere else on the rocket, you should switch to packaging tape for weight reduction. If you can, even try packaging tape on the fins, but test to see if it's strong enough to hold them in place before you compete. 
The materials you use on your fins seems a bit iffy though. Balsa is a bad material for rockets in general, and I'm glad you noticed that. Foam board might work, but I have a better, weight friendly solution you should maybe check out. I suggest you get Corrugated Plastic boards, and 0.007 inch plastic film to make a sort of hybrid material fin design. 

My design consists of a Trapezoid shaped fin, made out of a parallelogram shaped piece of corrugated plastic in the front (make sure the holes are parallel to the leading edge) 
and a triangle of flimsy plastic film on the back. The film is pulled taut from being taped between the bottle and the corrugated plastic leading edge. once you have this down, I would pinch the front of the corrugated plastic into a point for better aerodynamics (hence why I suggest that the holes be parallel to the leading edge.) Then tape this onto the bottle. 

since I don't know the overall design of your rocket, I suggest that you play around with this design, and work out which variation of this design works best on your rocket. 

Good luck at nationals, and happy flying!

Thanks, Fanglin! That helps a lot!
I'm not sure I understand your fin design, though.
Would you mind posting a picture of it?

-NeBH

Ouch! All of those launcher troubles sound tough! Are you using a cone or a T8 tube?

Since I ran out of time, I used a tube on one rocket, and had the other one be a basic lawn dart.
That one knocked me down to Tier 2, but I actually ended up in 17th place (Out of 38), so I think I did OK, given the circumstances.

But, there's a lot of room for improvement!

[Zioly]

Thanks, Zioly!

Unfortunately, my launcher has a pressure release valve that blows at ~50 psi, so I haven't been able to test at 60. Also, it was meant for 2 L bottles.
The manufacturer said that it "doesn't work as well" with 1 L, which I think (after you translate from lawyer-eze to experience-landic, of course) means

"After you work out your

air pressure issues (Click to Show Hidden Text)

There's an adapter that goes from the air hose on the compressor to the launcher. Well, we lost it. So I asked my mom to buy a new one. She did, but we opted for the cheap one. Guess what! It was leaky! Of course, I didn't realize that until I'd spent a few days struggling with the little booger...
So, I asked her to get another one (not the cheapest one this time). So we did that. I put that one together, and tried to use it. That one leaked too! Turns out, I was learning the difference between normal threads and pipe threads (i.e., you can tighten normal threads quite a bit before they break. But pipe threads...). Then, after all that, I found our other adapter (that actually works) underneath some sandpaper. Just lying there. :evil:

,the bottle gets stuck on the launcher! Obviously, you will get fairly wet when you do get the little booger off. Then, you try putting some oil on the launch tube. But that makes it even worse! Now it comes off while you're still pressurizing!"

Then, I ran out of time, and decided to focus mainly on my best event. Sorry for the rant... Anyway, I think I got about 10 seconds (total) at the competition. But I could be off by +/- 5 s.



Thanks, Fanglin! That helps a lot!
I'm not sure I understand your fin design, though.
Would you mind posting a picture of it?

-NeBH

Ouch! All of those launcher troubles sound tough! Are you using a cone or a T8 tube?

Since I ran out of time, I used a tube on one rocket, and had the other one be a basic lawn dart.
That one knocked me down to Tier 2, but I actually ended up in 17th place (Out of 38), so I think I did OK, given the circumstances.

But, there's a lot of room for improvement!

There always is! The spirit of Science Olympiad! Will I be seeing you and your rockets at Nationals, NeBH?

EDIT: Referred to your earlier post... yes, you are going to Nationals. Congrats! Then... I'll be seeing you and your rockets at Nationals! Good luck!

[NeBH]

Ouch! All of those launcher troubles sound tough! Are you using a cone or a T8 tube?

Since I ran out of time, I used a tube on one rocket, and had the other one be a basic lawn dart.
That one knocked me down to Tier 2, but I actually ended up in 17th place (Out of 38), so I think I did OK, given the circumstances.

But, there's a lot of room for improvement!

There always is! The spirit of Science Olympiad! Will I be seeing you and your rockets at Nationals, NeBH?

EDIT: Referred to your earlier post... yes, you are going to Nationals. Congrats! Then... I'll be seeing you and your rockets at Nationals! Good luck!

Thanks!
I saw you're doing Scrambler; I am too! Maybe I'll see you there!

[Fanglin]

[NeBH]

I don't think I'm "allowed" to see your image. When I click on the image icon, it says

Gone
Error 410

I'm not sure of exactly what that means, but I can see you linked to something in Gmail; I'm going to guess that's a security feature of some kind.
(I use Gmail too, so it's not a compatibility issue)
Can you see it on your end?

[Fanglin]

[NeBH]

Now it says this!


403. That’s an error.

Your client does not have permission to get

URL (Click to Show Hidden Text)

/lr1PcQ9iWNDOzBm57FN_eKXFKF1bvbfed4ohYqeY1tO1SvC3LEQZpM0phX6BhVmRtl4vkueucRHh3iJWWwhhRrIII4YNZQ_qseTD6qbI9DvdiN0-yplRyO44A2NiTFBZy-RDIbDbPtiNFtHYld1RLqjrjzHhJB9tn0NUpF1OImlLWZLVS0uGjApyFIhSXqSSHTWgGviqdL5KGHvPeihp1eAwPgF0L8wjzopn1Gc1gxo9S20s4FX3wW4F3ZVZ9zweHioZac_2GbdkyoSB8BoGEboQn3HtA9-7yTdTVWK5xmxeQKamQrh9VfAQj3RrDZPsg1uPPA365BqdWXJat14lSxLz1uI2Wv7JlXXSIi0maeYnYJQyAMqMNVHXgKp-qBGwfP-9LcEw49EZVs0L4ok2CzMhZdTTDJvpdgbUh5WgpIf-Ppmydftjx2omExzDW2SacZxns72BMBv067JEcVB0fQA_DRZEEWUNzuHboJyMkZGLrrqcRoOIceHj7dCxVciTtbC4u_cQW0akNGCxnw7NrH24sopaaTePN98zLdLDGYEtn79kSjUDThAjYr-w-L__kbX7B2OoBfOAzdnxdHhxkHKUFFpCNhSjl_YpfNn0yxP0jhUVWrWYhp8bLKB9hMGSkzB0LQOm_Nd80Lx2krO8ix6yqG1UOKcuPKeqTxiGWLvpL9xYaBDPIKpO_X5bWM3ntMoCXa0=s0-l75-ft-l75-ft

from this server. (Client IP address: I took this part out, just in case)

Forbidden That’s all we know.

I think I can't access it because you're linking to something in your Gmail.
Do you have a google drive? If so, you might be able to use a "shareable link" to post it.
(Or you can PM it to me, if you want.)

[NeBH]

Here's a google drive link to the picture Fanglin took!

https://drive.google.com/file/d/0Bzydf8 ... sp=sharing

Thanks again, Fanglin!
And, sorry, everybody, for all the "spam" posts...

[Zioly]

Anyone happen to remember their times and tier from Saturday? I was caught up in an appeal, so I didn't get to ask about my time. Tier 1 in the end though.