Vern Estes Big Bertha from birth to 2019

Discussion in 'Low Power Rocketry (LPR)' started by Tom Howe, May 18, 2019.

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  1. May 18, 2019 #1

    Tom Howe

    Tom Howe

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    Hello all,
    I am new to this forum but not to rocketry, albeit with a 42 or so year gap. As a tip of the hat to some of my earliest rocket builds in the late 60's I am scratch building a few Estes designs, one being the Big Bertha. I am curious if anyone knows when Vern's Big Berth design evolved from his original plan as published in the Estes newsletter (and the early kit version) to the revised design where the original (short) engine holder is replaced by a much longer holder assembly, no doubt to improve pressurization of the parachute compartment. There is an article posted on line detailing the evolution of Bertha but I didn't notice any mention of this change. So if any of you have any thoughts please share them. I'm just curious.

    Thx, Tom H.

    PS: Anyone aware of any rocket clubs in the Western MA - Northern CT area? I'm getting the notion that now that pot is legal in MA They are attaining a different "high" and watching the lawn weeds grow....

    Big Bertha Original Plan.png Big Bertha revised Plan.jpg
     
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  2. May 24, 2019 #2

    milehigh

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  3. May 25, 2019 #3

    BEC

    BEC

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    Recent versions don't have the longer stuffer tube.....and so in that respect are closer to the original than the second version you posted there. It wouldn't hurt even current ones to have it... both my wife and I have had parachutes fail to get all the way—out once in awhile—on BBs built from recent kits.

    Another key difference is the shape of the nose cone. The nose cone closest to the original shape that's currently available is this one: http://www.erockets.biz/semroc-balsa-nose-cone-bt-60-3-1-bezier/

    I expect there may have been subtle fin shape differences over the years as well, but I'm not gonna go there :D. I've done far too much of that with the Alpha. :eek:
     
  4. May 25, 2019 #4

    GlenP

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    Very cool article from the LAUNCH magazine. I wonder if the interview with Lee Piester is on the web somewhere from that issue.

    On Page 31, the Scout behind Vern's shoulder in the canister that flew into space is on display in the Museum of Flight.

    [​IMG]
     
  5. May 26, 2019 #5

    Tom Howe

    Tom Howe

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  6. May 26, 2019 #6

    Tom Howe

    Tom Howe

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    I know there is a shape difference. I bought a couple of the balsa equivalents from JonRocket. There is a shape difference. If I feel energetic enough I may install them o my lathe and tweak them. Ah yes, the Alpha. My dad gave me the Alpha kit with the launch pad (Electro Launch was it?). Those damned Everready photo flash batteries that you installed in the red plastic base never would light an igniter. Finally after too many attempts dad got some large jumper cable type alligator clips and whatever gauge twin lead and wired up the launch controller. Now that worked very well. My Alpha, which I think flew with an A8-3 engine flew exactly one time, landing in the valley of a nearby house. It stayed up there through the winter of 1969 (so about 6 months) when melting snow moved like a glacier bringing it down. I have vague recollections of looking at the moshed body tube and dropping it into the trash. Never built another.
     
  7. May 26, 2019 #7

    BEC

    BEC

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    Funny thing about the Electro-Launch. With four modern alkaline D cells in it (say, Duracell) it is really quite capable. But of course now we're using igniters/starters designed for 6V instead of using that one with the blue whatever-it-was on it from back then or the coil of fine nichrome wound around the safety key.

    I have two Electro-Launches (one of each major version) that I bring out for our club's "Classics" launch every September and I fly off the older one of them from time to time in between.

    The original BNC-60L shape is longer than the current plastic ones. I'm not sure what 60L balsa nose cone Roger is selling - probably the BMS-made version. Perhaps it would be amenable to a "tweak".
     
  8. May 30, 2019 #8

    gna

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  9. Jun 10, 2019 #9

    MarkB.

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