Launch! Schoolyard Soccer Field, July 20, 2019

My alarm went off at 6:45 a.m., I headed for the soccer field by 7:00. Clear skies - no winds! Early is the only way to beat the heat.

The indestructible Estes CURVILINEAR was a great first launch to make sure the batteries, controller and conditions are good.
The A8-3 engine got it to an estimated 200 feet.








Here's the first launch of the recently finished Semroc CENTURION.
An Estes B6-4 (in a used D engine casing adapter) got it to 300'. Ejection was perfect, right as the rocket turned over. I caught the model before it touched down.
The Centuri style Baffle worked - no wadding and no melts on the 18' parachute.
For me, this is the ideal demonstration rocket. Slow off the launcher with manageable altitudes. That, and it's just a clean design.

Next up was the "fibre-finned" Semroc NOMAD.
I remember building this Centuri kit in the seventies and being surprised by the new stiff, card stock fins.

The Estes A8-3 probably reached 200'. A clean, textbook launch and recovery.

The main reason for today's launch was a small tribute to the moon landing fifty years ago. For an hour I felt 13 years old again. I found myself running to catch rockets before they could touch the ground.

My favorite Dr. Zooch SATURN V was flown with an Estes B6-4.
Boost was good but the rocket angled to the East, over the fence and above the four lane road!
By this time the winds were starting up and brought it back within 50 feet of the tripod launcher. It landed with a "Thock!", I thought there might be damage. One fin was torn off and a nozzle bell was loose, both repairable. This was the 14th launch for this model.

My last flight seemed appropriate -
The EARTH TO THE MOON Spool flew with an Estes C6-0 engine. Boost got it to 175' with a fast end over end spinning recovery.
The Earth "plate" is on the bottom and the moon print faces up. No launch lug, there is a hole for the launch rod in each plate.

Five up, five recovered with small Saturn V repairs.
I seem to dread getting up this early for rocket launches, but feel like I've got a lot accomplished by the end of the day.

Centurion Project, Finished!

For comparison - 
This is the Estes Cosmic Explorer - leaner, longer nose cone and a bit shorter. 1.35" diameter, BT-55






Here's the (Centuri) Semroc Centurion, the real subject piece for this build.

Stockier, shorter nose cone and taller. ST-16 tube at 1.64" diameter.
This is probably the better demonstration bird of the two.

These last five pictures are of the Semroc Centurion.





Here's the two different interchangeable engine mounts.

On the left - the two 18mm cluster mount. This model should be good with two C6-5s.
On the right is the single 24mm mount for a D12-5.
By the looks of the picture I'm going to lightly ream the rough launch lug end with a sharpened dowel.

And the top!
I'm glad to finally get back to and finish this Centurion Project.
I hope to launch the two engine cluster version after the new NEFAR field is established.

Centurion Project, Part 13, Tying It All Up!

CENTURION:
I glued the baffle into to the (shown upside down here) upper body tube. There is a pencil mark at the halfway point. The other lines are leftover paint lines when the model was spray painted white.

CENTURION:
The 1/4" wide shock cord was tied to the screw eye using a Duncan Loop Knot.







CENTURION:
The parachute shroud lines were laced through the latch end of the snap swivel. This method was suggested by Ed Mitton.
The other end was tied to an overhand knot in the shock cord with a double loop of some scrap shroud line.

COSMIC EXPLORER:
The 18" parachute seems a big large for this size model, a 15" chute would be better.
TIP: You are better off cutting out the spill hole before assembling the parachute. I had already assembled the chute.
On the left you can see a shroud line running underneath the spill hole location. Be sure to clear the shroud lines outside the perimeter of the spill hole before cutting the chute with your knife.

CENTURION:
I don't like overall covering a rocket with Future or acrylic finishes. Rockets can get sticky in humid weather.

TIP: I will roll a little Future over the open ends of the decals - just the joints and cut ends.

Saturn V Side By Side Launch

There were a few Saturn V launch videos posted yesterday -
Here's one of the better ones by CoolBlueZRI.

Side by side time coordinated video of the 1969 Apollo 11 launch and a Estes #2157 Saturn V Model Rocket. To see the video - CLICK HERE

Centurion Project, Part 12, More Decals and Trimming

Here's the decals from the Semroc Centurion kit - not nearly as many as red stripes as supplied with the Estes Cosmic Explorer.





CENTURION:
The original Centuri kit did have a red stripe running down both sides of the body. The Semroc reissue kit only gives you red stripes for a single fin stripe (both sides) and a horizontal stripe below the black upper section.

CENTURION:
GOTCHA: One single horizontal red stripe isn't long enough to reach around the body tube! This wrap was made from two separate pieces, there's another overlap around the right side.

I decided to use the two remaining stripes on one side of two opposite fins.

The ends were pressed down over the rounded leading and squared trailing edges.
The picture on the right shows the tops after trimming with a razor blade. The decals are thin, it only takes a very light pass with the blade to cut through the ends.

CENTURION:
GOTCHA: I don't know why the decal has two Centurion name decals. This makes no sense. You can apply one on the open side, but the launch lug would get in the way of the second decal.
I would have rather had more red stripes on the decal sheet.

Centurion Project, Part 11, Edges and Decals

I'll be bouncing back and forth between the finishing and decals on the Semroc Centurion and Estes Cosmic Explorer. If you see the model name at the top of the paragraph, that's the model I'm working on at the moment.


CENTURION
I ran a Sharpie around the shoulder lip so you wouldn't see the balsa shoulder if the nose cone wasn't all the way in.




CENTURION
The upper black body tube edge got a swipe of a Sharpie to make a sharper color separation when the tubes are joined together. This is a dry fit.

COSMIC EXPLORER
Decals - The vertical red stripes that run up the body tube have to be pieced together. Sight from the rear to make sure they are straight all the way up the tube.

COSMIC EXPLORER
I had a crack and break on the horizontal red stripe. Sometimes you can salvage a broken decal, but not this time.

TIP: Keep old decals! I found decals from an old Estes kit. Who knows where I came across this decal. The red color and width were very close.

COSMIC EXPLORER
The start point of the decal is on the back, in line with the launch lug.
Nobody will notice the decal patch on the launcher.

Centurion Project, Part 10, Black and White Paint

This is a very easy model to paint, the low end is white, the upper tube and nose cone are black.
TIP: Always think ahead when assembling a rocket. The instructions tell you to glue the two body tube sections together with a coupler before finishing. Wait to glue the two body tubes and spray them separately - no masking!
After you are happy with the upper and lower sections in their different colors, then glue them together.

Here's one of those examples where the paint can help fill some low areas, here on the launch lug glue fillet.
Sanding with 400 grit took some paint off the fillet . After the final coat of paint you probably won't even notice the dips in the glue line.

On the upper body, I did do an overall white undercoat and followed by light sanding.
There is no need to get a consistent, bright white cover on the upper section - it will end up being black.

Go right to the gloss black!
If the final colors are light colors, you do want a even, bright white undercoat. This isn't needed when spraying the dark black.