Enerjet 1340 Build Finished! Part 9

Here's the model FINISHED!

Well Almost - Where is that old decal sheet of Enerjet logos?

Enerjet 1340 build Monokote Trim Part 8

I've already placed the 1/2" band of aluminum trim on the lower end of the body tube.

The fin can was slid down to the 1/2" trim band. The largest aluminum trim is last, by now I've had practice for the most difficult wrap.

Look close and you can see the seams were filled with Carpenter's Wood Filler. The trim film is very thin, body tube seams will show through the surface.

You can see in the picture, once again I only removed about 1/4" of the backing material for placement on the alignment line.

Here's the fin can with the molded launch lug. I didn't think ahead about the body tube peeking out of the front of the tapered lug opening. I cut a small piece from scrap aluminum trim. I set it on the tip of my knife and set it inside over the exposed tube. It butts up against the black trim band.

Enerjet 1340 Build Monokote Trim Part 8

I was lucky to find Monokote Trim today at a local hobby store.

The only gold sheet they had was old. I hoped the bends and creases wouldn't show on the finished model. The aluminum sheet looked new.

I wrapped copy paper around the body tube to get the approximate circumference.

A thin pencil line was drawn down the body tube for edge alignment.

The gold piece was cut to size, slightly larger than the circumference.

Past experience with pressure sensitive trim (stickers of all sizes) reminded me not to take it entirely off the backing sheet. I only cut away 1/4" of the backing along the edge to line it up on the pencil mark.

As I worked around the tube, more of the backing sheet was pulled back. I pressed out any bubbles as I went.

Just be sure your body tube and fingers are clean before starting. Any speck of dust or lint will show under the Monokote surface.

At the end there was a slight overlap of about 1/16", hardly noticeable when burnished down.

After the gold was in place, I cut black bands from electrical tape. I went to the Enerjet flyer site and kept enlarging the image until it was close to the size of my ST-13 body tube. The bands ended up being just over 1/4" wide.

To be sure the bands were put on straight around the tube, I wrapped a piece of copy paper around the tube for a guide. Look close in the picture, you can see the paper guide just under the black band.

Here's the finished upper body.

The gold wrap wasn't any problem, the creases and divots didn't show when all was rubbed down.

Enerjet 1340 Paint Schemes Part 7

Bob (Initiator001 from YORF) said it would be okay to show his three versions of the Enerjet 1340. Thanks Bob!

From left to right:

This prototype version was seen on the cover of the Enerjet flyer. It had a shorter nose cone.

The middle version reflects the assembly drawing from the middle of the same flyer. It sports the longer PNC-56 nose cone. This is the version I'm building and will finish it as shown here.

The red, white and blue model is a replica of the 1340 that flew at NARAM 16 in 1974.

Enerjet 1340 Build Part 6 Painting Plan

Painting the back end of the 1340 will be a bit tricky.

Here's a dry fit of the fin can. In the end, the fin can will be white.

The inside diameter of the fin can is slightly wider at it's back end.

It'll slide down from the top of the body tube, but not easily from the bottom up.

If I were to pre-paint the body tube, sliding the fin can over the tube from the top would scratch the paint.

The bottom tube will be covered with Silver (or aluminum) Trim Monokote.

Also, the last half inch below the fin can will be silver.

It looks as if the fin can will be locked in place surrounded by the trim Monokote.

On the upper end - going up:

The .10" exposed coupler will be painted white.

Immediately above that is a 1/4" black band.

The lower half of the upper tube is gold trim Monokote, then another 1/4" black band.

The upper half of the upper tube and nose cone will be white.

Enerjet 1340 Build Part 5 Coupler

I didn't want to use the plastic coupler that was molded to the nose cone.

Making something close to the original would take a little extra work.

The Enerjet assembly drawing shows a blow-molded plastic adapter with only .10" exposed between the joined tubes.

A JTC-13 black coupler was ordered from Semroc. I used my Odd'l Rockets tube cutter to make a .10" piece of ST-13 to slip over the coupler.

The coupler is only 1 1/2" long. I wanted a longer shoulder into the lower tube. I decided to glue the .10" piece so that a 7/8" shoulder would slide into the lower end. The upper side of the coupler is left with 1/2" for gluing into the upper ST-13 tube.

For some reason, I kept the balsa shoulder I had cut off an old BT-60 nose cone. This would go into the lower end of the coupler and allow for a screw eye attachment.

I set the coupler over the scrap shoulder and drew a pencil line around the inside. The balsa was carved down close to the inside coupler diameter. It was friction fit into place. I left a little overhang of the lower end and sanded flush with a sanding block.

Enerjet 1340 Build Part 4

I wanted to use Es and Fs like the original Enerjet 1340 line but with currently available 24mm engines.

A heavy duty BT-50 was cut to 3 3/4" for the engine tube.

The tubing was marked at 1/4" for the engine hook notch. The centering ring locations were marked at 1/2" from the top and 1 1/4" from the bottom.

For centering rings I'm using Semroc CR-9-13s. By themselves they are .050" thick. I'll be using four in total, two will be laminated together to make one single thicker ring.

22" of 150 lb. Kevlar was cut to be attached to the mount. A small notch was cut in the upper ring for the Kevlar to pass through.

After the engine hook was set in the notch, black electrical tape was wrapped to retain it. The Kevlar was tied and the centering rings glued in place on their marked lines.

An engine block was glued in the forward end against the top bend of the engine hook.

The mount was glued into the lower, longer ST-13 with the motor mount tube flush with the end of the main body tube.

Enerjet 1340 Build Part 3

The nose cone is 6.4" long just like the 1340 specifications.

The MARS Project nose cone is molded together with a coupler.

The MARS instructions say to simply "wiggle the nose cone/connector unit until it breaks apart at the narrow neck." It broke apart easily and fairly clean. Luckily after the molding seams were cut and sanded off, not much filling was needed.

That Mars coupler would show 7/8" exposed when joining the two ST-13 tubes together. The original 1340 had only .10" showing between the tubing.

I couldn't use the upper body tube from the MARS rocket. It had the paper sticker wrapped around the tube saying Centuri Rockets. I tried to remove it, but it was a mess after all these years.

I needed two tubes, an 8" and a 13" ST-13.

The original (yellowing) lower tube was cut to 8".

I ordered a 13" length of ST-13 tubing from Semroc to make up what I needed.

Here's the two main plastic pieces from the "kit", after sanding off the nose cone molding seams and cleaning up the rough edges on the fin can.

Enerjet 1340 Build Part 2

The MARS package contained the plastic fin can from the Centuri Argus kit from 1973. The same fin unit and nose cone was also used in the Centuri Phoenix Bird, Estes Maniac and still part of the Estes Eliminator. With the forward fin fairings it reflects the Centuri style.

The fin unit was rough at the top above the fins. It'll take a bit of cleaning up.

Notice the integrated launch lug. This was the first time I'd ever seen the lug molded into the fin unit.

Enerjet 1340 Build Part 1

Parts for the Enerjet 1340. The shorter body tube at the top with the Centuri Rockets sticker will be replaced with the body tube below the nose cone. Everything is here except for the Kevlar, shock cord and streamer.

I received one of the old Centuri M.A.R.S. Project parts bags from JonRocket.com a while back. The MARS Project was and abbreviation for "Merchandising Aid for Rocket Selling". These were sent out to hobby shops for display. They weren't necessarily made for flight, but I know many have been converted.

I'd always admired the old Enerjet 1340 design ever since I was sent the flyers back in the 1970s. That flyer talked about all the applications for the "Sounding" rocket. From pollution sampling, cloud seeding, avalanche control, line laying and signal flares, there wasn't anything this rocket couldn't do.

It was recovered by a 12" parachute or 10' drogue streamer. This version will fly with 24mm Ds, Es and Fs.

The Enerjet 1340 made it's debut back in 1972. It was not pictured in the Enerjet catalog.

You can view the flyer at: http://plans.rocketshoppe.com/enerjet/enj1340/enj1340.htm