Thursday, October 10, 2019

Estes Boosted Bertha #001946 Build, Part 1 Parts

Estes has had many Big Bertha variations over the years, now a two stager!
I've seen a few two stage Bertha flights on the forums over the years, it's now in a kit for all.
Lots of balsa and decals!

The retro checkerboards remind me of the generic decal sheets from the 1960s.

There is some gap staging on this model.
The best feature are the new 18mm engine screw-on retainers.


  1. I’m curious about how the engine retainer holds up on the sustainer - how many flights will it take for the booster motor’s ignition charge to “cook” the screw on retainer ring?

    1. Hi Openroad,
      I don't have an answer on this one. It was a build for Estes and not launched.
      I would imagine there is some hot flame hitting the upper stage retainer ring, eventually needing replacement. Estes does now sell them separately.

  2. I have five flights on my Boosted Bertha. The sustainer's motor retainer ring is still serviceable - I'd guess it has 3-5 more flights in it before it won't fit well enough to be trusted. I have some of the 18mm retainers that are sold separately on hand, so I do have spares.

    (I don't see any way to attach an image or I would....)