Water Rocket Forum

I'm back in the swing of things and I'll be making another attempt at the Class B record this summer. I've had the first version of a new rocket ready to go for quite some time and finally managed to launch it yesterday. I managed one flight at 240 psi, and I reached 940'. I'm not sure how much more I can squeeze out of this particular rocket, so I might just have to make a bigger booster.

I'm holding off on rocket specs and pictures (and the meaning of "MBD") until I've either given up or broken the record. I don't have onboard footage because I broke my MD80 when I had a premature launcher release. I've got some replacement MD80's on the way, so I'll get some footage when they arrive. For now, I'll just give you the altimeter log. More to come.

Alex

Wow! Great job Alex.
Looks like you're going to break the record soon.

I'm still working on my first class B rocket, just have to do a few small things on the launcher and then it's ready to go.

Wow! That looks really interesting!

Can't wait to see what the secret design is!

hmmm...

I've been thinking about what MBD stands for the last few days.

BD could be Boosted Dart???

arjan wrote:hmmm...

I've been thinking about what MBD stands for the last few days.

BD could be Boosted Dart???

Arjan, I can neither confirm nor deny that. Oh what the hell, yes you are right. The M stands for micro. The booster is a single 1.5L bottle, reinforced with more bottles. Unfortunately, I don't think I can up the pressure enough to break the record. So I'll either have to make the booster bigger or use other reinforcing techniques. I guess might have to change the name to "Mini Boosted Dart", then. I thought it would have been really cool if I could have broken the record with an all PET 1.5L rocket.

Alex

940' with a single reinforced 1.5L bottle?!

Wow, I think you just revealed "the way to go" for the multi stage record, amazing.

Did you optimize the weight, shape and smoothness of your dart? Maybe this together with a bit more pressure would do the job.

Thanks for sharing this with us.

Yes, I really think a boosted dart is the way to go for the class B. A pressurized sustainer is complicated, and I think most two stage rockets would go higher if the builder put the same amount of effort into a single stage. They are just fun to watch. With a boosted dart, however, I think you actually have an advantage.

The dart is made out of a t8 FTC. It would be hard to make it much narrower and still house an altimeter and a video camera. I could have made it slightly lighter, and done a slightly better job on the fins (specifically airfoil cross section and smooth fin fillets). It might also be possible to make it slightly shorter, but none of these improvements would gain much. The booster is where I can really improve.

Alex

Does your dart have a boat tail? I've read some articles about it and seems to reduce drag a lot.
But you've probably thought about that.

I'hope to launch my class B rocket soon, waiting for the good weather, after that I'll definately do some boosted dart experiments.

SaskAlex wrote:The dart is made out of a t8 FTC. It would be hard to make it much narrower and still house an altimeter and a video camera.

And what about this camera: Together with this altimeter: Then it should be possible to make a dart of 15mm dia.

SaskAlex wrote:I'm back in the swing of things and I'll be making another attempt at the Class B record this summer. I've had the first version of a new rocket ready to go for quite some time and finally managed to launch it yesterday. I managed one flight at 240 psi, and I reached 940'. I'm not sure how much more I can squeeze out of this particular rocket, so I might just have to make a bigger booster.

I'm holding off on rocket specs and pictures (and the meaning of "MBD") until I've either given up or broken the record. I don't have onboard footage because I broke my MD80 when I had a premature launcher release. I've got some replacement MD80's on the way, so I'll get some footage when they arrive. For now, I'll just give you the altimeter log. More to come.

Alex

Great job dude.

I am confident you will reach your goal. You are focusing on all the important details.