Thursday, April 4, 2013

Centurion Project Problem

I'm suspending the build of the interchangeable mounts in the Centurion build. The mount design would have allowed a single 24mm, single 18mm, 2x 18mm cluster and a 3x 18mm cluster configurations.

Instead of the interchangeable removable mounts, I'll install a single 24mm engine mount and use a standard 18mm 20/50 adapter.

While I think the design has real possibilities there could be a problem with ejection charge leaks.

Look at the picture to the left - With the lock slid in, turned and locked, the "half holes" in the centering rings let some of the ejection charge go out the back. There may not be enough of the ejection going forward to push out the parachute.
While the picture shows the single 24mm mount, the design would have also allowed a single 18mm, 2x 18mm cluster and a 3x 18mm cluster configurations (3x 18mm with three dowels, not four)

I'll continue with posts showing the build of the mounts, the locking design is very inventive. It makes good food for thought, and might inspire a solution.

3 comments:

  1. Check out the instructions for the Semroc AeroDart, which used the fin tabs to hold in the interchangeable mounts - http://www.semroc.com/Documents/pdf/SLS%20Aero-Dart.pdf

    A less elegant solution - but very workable - is the one used by Centuri in the RX-16 rocket of their Power System set:

    http://www.ninfinger.org/rockets/catalogs/centuri_pshandbook/cenrx18.html

    Love your blog - has helped me in many builds!

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  2. Hi Bill,
    I am familiar with the Semroc SLS engine mounts. I've built the Semroc Explorer. I just thought this new design had some merit for models without TTW fins.
    I had a Centuri Power System set and remember that mount. But Semroc had trouble with their similar outside engine hook retainer on the big Brighton model. Strong ejection charges from clusters blew the mount right out the back!
    A standard (outside) engine hook wasn't enough to keep the mount in place. There is a solution out there, I just haven't found it yet!

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  3. My Big Bertha build on TRF used plastic pop rivets to hold the interchangeable mounts. But my guess is you would not like the looks.

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