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MBD- my new Class B attempt

Posted: Sat Jun 08, 2013 1:11 pm
by SaskAlex
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

Re: MBD- my new Class B attempt

Posted: Sat Jun 08, 2013 3:10 pm
by arjan
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.

Re: MBD- my new Class B attempt

Posted: Sat Jun 08, 2013 10:31 pm
by U.S. Water Rockets1
Wow! That looks really interesting!

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

Re: MBD- my new Class B attempt

Posted: Fri Jun 14, 2013 1:58 pm
by arjan
hmmm...

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

BD could be Boosted Dart???

Re: MBD- my new Class B attempt

Posted: Fri Jun 14, 2013 3:54 pm
by SaskAlex
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

Re: MBD- my new Class B attempt

Posted: Fri Jun 14, 2013 4:27 pm
by arjan
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.

Re: MBD- my new Class B attempt

Posted: Fri Jun 14, 2013 6:26 pm
by SaskAlex
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

Re: MBD- my new Class B attempt

Posted: Sat Jun 15, 2013 8:07 am
by arjan
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.

Re: MBD- my new Class B attempt

Posted: Sat Jun 15, 2013 11:28 am
by arjan
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:
Spy_Pen_Zwart.jpg
Together with this altimeter:
altimeter-main.jpg
Then it should be possible to make a dart of 15mm dia.

Re: MBD- my new Class B attempt

Posted: Sun Jul 07, 2013 6:28 pm
by Nick B
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.