There are only two situations when I would suggest a B4-4 instead of a B6-4:

• Upper stage motor in a draggy rocket - the larger nozzle makes the motor easier to ignite
• Lightly built glider

Surely someone must be buying them.


Bill

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It is well past time to Drill, Baby, Drill!

If your June, July, August and September was like this, you might just hate summer too...

Please unload your question before you ask it unless you have a concealed harry permit.

: countdown begin cr dup . 1- ?dup 0= until cr ." Launch!" cr ;

Give a man a rocket and he will fly for a day; teach him to build and he will spend the rest of his days sanding...

I've flown the B4-4 in medium sized rockets with good success. Medium as in smaller than a Bertha....Cherokee D or Nike-X sized for instance. For that matter, I've flown it in Berthas with no ill effects too, but I generally fly in calm winds late in the evening. It would probably tip off in a breeze.

The B4-x actually has a higher measured max thrust (0.61N higher) than the B6-x, but tapers off much quicker. It's a little easier to get in-flight photos with it, as the thrust spike tapers before it leaves the rod. Slower liftoff means less blur and it's easier to keep in the camera frame.

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I love sanding.

That is almost guaranteed to have a good motor put in it. One of the guys in the club had this beatup old rocket that he used for any questionable motors and it kept on surviving.

I had a tube of Estes D13-5's that I burned in the old motor program. Knowing that they were "iffy" at best, they did not get used in pristeen rockets but they went into half decent condition rockets and the first 2 out of that tube catoed, destroying my rockets.

I gave the third one away to be used in the old "beater" and, of course, it had a perfect flight.

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Bob Harrington
NAR #62740 L1
AMA #46042
CMASS & RIMRA Member

Just a quick reminder... in addition to the April launch being the opportunity to cato your favorite rocket that lives on a shelf with your favorite motor that lives in a drawer, the April sod field is traditionally the Steve Chester Memorial Spring Cleaning Swap Meet, so sweep the basement floor and bring out those extra unused parts to trade or give away. This will be the 4th anniversary of Steve moving away. I still fly his Estes Corkscrew.

Steve, if you're still out there, thanks!

Sather

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AP used in 2010: 28,044 Ns (36.9% O)
AP used in 2011: 43,488 Ns (6.2% P)
Highest altitude achieved: 21,981' AGL

"Gravity is a cruel and unpredictable mistress"

And we were all scared of the DE-certified motors, when it was the CERTIFIED motors we should have been running from today! The couple B14's I saw today looked great, I'll let Rex and Russ tell you about the F50,000 and the E9-20...
Pictures are on the way Rex.

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www.wooshrocketry.org NAR Sec. 558
Look us up on YouTube: http://www.youtube.com/user/guytogo75?feature=mhee
unstable by design

went to fly my Jayhawk today. rocket prepped, check. prep a nice (presumably) new Estes F50-6t according to the instructions(using a sonic igniter too), check. start count down, press the red button at zero. we heard a small pop from the igniter...and a much louder pop from the motor. my jayhawk will never be quite the same again.
mess report filed, and estes notified of the cato. kinda puts a damper on ones day when this happens first thing
rex

Attached Thumbnails

 

Maybe it's a good thing we had some other excitement to take your mind off it, Russ?

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www.wooshrocketry.org NAR Sec. 558
Look us up on YouTube: http://www.youtube.com/user/guytogo75?feature=mhee
unstable by design

perhaps the next time I decide to try out an SU motor, I should try it in my wildchild...would drive tim nuts wondering how I manged to destroy it .
rex

Ouch !
That's a real bummer on that nice Jayhawk.

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When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

I would not have expected a brand new motor from Estes to CATO that way. Maybe the shipment heat cycled when it was shipped from Aerotech to Estes to whomever the distributor was. Poor publicity for the new line of motors so exorbitantly priced to begin with...
Seems unusual to me.
Aerotech or Estes owes you a new Jayhawk, though, I would think.

Allen