Enerjet 1340/20 Project

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Jack Hydrazine

Well-Known Member
TRF Supporter
Joined
May 31, 2011
Messages
333
Reaction score
132
Back in the early 1980s I read the 4th edition of the Handbook of Model Rocketry...


and found a photo of this rocket...


The Enerjet 1340/20!


I really wanted to build and fly this rocket, but never did...until today.

I have already built the Enerjet 1340 which happens to have the autograph of Lee Piester inscribed on it.

 
PDF of Centuri 1340/20 promo material.
https://www.oldrocketplans.com/enerjet/enj1340-20/enj1340-20.pdf


Parts List:

(1) Centuri #13 Plastic Fin Unit from an Estes Eliminator (also used in the Centuri Phoenix Bird (#5407), Centuri Argus (#5039), Estes Maniac(#2091), Estes Long Shot (#1980), Estes Challenger II (#1330) among others.)

(1) 12" Estes BT-56/Centuri #13 airframe tube
https://www.erockets.biz/st-13/

(1) #20 to #13 Balsa Reducer
https://www.erockets.biz/semroc-balsa-reducer-13-to-20/

(1) 10" Centuri #20 airframe tube
https://www.erockets.biz/new-category-3/

(1) Semroc Balsa Nose Cone 2025
https://www.erockets.biz/semroc-balsa-nose-cone-20-2-5-elliptical-sem-bc-2025/

(1) 29mm x 5.0" MMT

(1) 29mm to Centuri #13 motor mount rings (scratch built)

(1) Shock cord

(1) Screw Eye

(1) Shock Cord Mount

(2) Parachutes (size will be determined later)

Decals
https://www.oldrocketplans.com/decals.htm

(2) 3/16" Launch Lugs

(1) Launch Lug Standoff
 
Motor mount tube and centering rings...


Make a mark around one end of the MMT that is half an inch from the end.

This 29mm motor mount tube is cut to five inches in length. Two half inch lengths of the same 29mm source is cut and split width-wise only once. Then slide onto them onto the motor mount tube and glued in place. You may have to sand a little to make sure it fits into the airframe tube.
 
WyxnTPY

020.jpg

Glue in airframe tube into Plastic Fin Unit with about 1/8" of the motor end of the airframe tube sticking out past the fin unit.
 
Now moving on the recovery system's shock cord and mount.

The shock cord mount is plain piece of paper folded into three sections. The shock cord is 3/8" width elastic band about one meter in length.

Here is the shock cord glued to the mount.

023.jpg
 
I 3D designed the fin can in order to make a launch lug that will fit over the one built into it to work with the 1340/20. It is a faithful reproduction you can download for free from Thingiverse and print. I have not printed it yet, but will in the future. Will fit any Centuri ST-13 and Estes BT-56 tubing. You can also scale it up or down to fit any other tubing.

https://www.thingiverse.com/thing:3641770
 
Enerjet-1340-Fin-Can-Pic.jpg


I 3D designed the fin can in order to make a launch lug that will fit over the one built into it to work with the 1340/20. It is a faithful reproduction you can download for free from Thingiverse and print. I have not printed it yet, but will in the future. Will fit any Centuri ST-13 and Estes BT-56 tubing. You can also scale it up or down to fit any other tubing.

This is a replacement fin can for the following model rockets:

Enerjet 1340
Enerjet 1340/20
Centuri Phoenix Bird
Centuri Argus
Centuri MARS Project
Estes Longshot
Estes Maniac
Estes Challenger II
Estes Eliminator
Estes Eliminator XL

https://www.thingiverse.com/thing:3641770
 
Last edited:
Has anybody been able to color match the modern plastics to the old kits?

Colors I can confirm:
Black:
Centuri Phoenix Bird (5407)
Estes Challenger II (1330)
Estes Longshot (2128)

Yellow:
Estes Eliminator (1950)
Estes Eliminator XL (1460)


Blue:
Centuri MARS Project (5313)
Estes Maniac (2091)

Red:
Centuri Argus (KB-9)

I've seen photos of white fin cans for the Enerjet 1340, but I cannot confirm that they are not painted white or actually molded in a white plastic. I've also seen shots that look like it came in red, and even possibly blue, but again I can't confirm if they are stock kits, or clones.

[EDIT] An inquiry over at YORF has some confirmation on red and blue for the 1340s kits, and a possibility for orange even. No confirmation for any other colors at this time for those kits.

 
Last edited:
Has anybody been able to color match the modern plastics to the old kits?

[EDIT] An inquiry over at YORF has some confirmation on red and blue for the 1340s kits, and a possibility for orange even. No confirmation for any other colors at this time for those kits.


How about the color of the band on the payload bay tubing? It looks either like a metallic gold or metallic silver/aluminum.​
 

How about the color of the band on the payload bay tubing? It looks either like a metallic gold or metallic silver/aluminum.​
Every thing I have been able to turn up on the 1340/20 is that it's silver/aluminum. Now, I'm trying to identify my sources... However, I've been up since 2am, and its almost 9 now. I'm going to have to call it a "night".

Jim
 
Last edited:
Every thing I have been able to turn up on the 1340/20 is that it's silver/aluminum. Now, I'm trying to identify my sources... However, I've been up since 2am, and its almost 9 now. I'm going to have to call it a "night".

Jim

I appreciate your help with this. The fin can in the photo does look like red based upon the "ENERJET" decal and the band does look like silver/aluminum.
 
I found a website that colorizes black-and-white photos and tried it out with the original photo with great success. It does confirm that the fin can is red and the band on the payload bay is silver/aluminum.
Enerjet-1340-20-Cover-Page-Coloized.jpg
 
I found out that TRF member Initiator001 is an expert on the 1340 and 1340/20 as well as the Nike Ram. How do I clue him in on this thread and his expertise?
 
I found out that TRF member Initiator001 is an expert on the 1340 and 1340/20 as well as the Nike Ram. How do I clue him in on this thread and his expertise?
Send him a PM/Start a Conversation if he has his preferences configured he will recieve a notification there is a message waiting.
 
Here's an old thread over on YORF about this same subject:

https://forums.rocketshoppe.com/showthread.php?t=784
Thanks for the background! That didn't show up in my google search on the subject. Likely since there were so few images included.

Man it would be nice if people would include recent *COLOR* photos of their original built rockets or bagged kits. To my knowledge, I haven't seen any color photos the orange fin cans mentioned, and the reds are pretty rare.

Then there's that whole thing about the white fin can. Where did that come from?
 
Last edited:
Model Rocket Building did the 1340 on his blog in 2010. The color scheme was white with aluminum and gold monokote trim
 
Back
Top