Estes Eliminator to Enerjet 1340 project
 

I picked up several of the Estes Eliminator kits during the recent clearance and have one earmarked to clone an Enerjet 1340. I already have a section of 29mm (Semroc #115) heavy walled tubing to serve as the engine tube, and the OD of the motor tube and ID of the body tube are close enough that a wrap or two of masking tape and some epoxy seem like a way around the lack of centering rings. How have those of you who have cloned one of the 1340s handled this?

As I recall on the original, the motor tube was a 'glove' fit inside the body tube.

But, the original 1340 body tube was heavy walled and the original Enerjet 1340 nosecone reflected this in that it had an appropriate shoulder and outer 'thickness' to match up to the thicker walled body tube. In other words, while the Eliminator fin can is essentially the same as the original Enerjet 1340 fin can, the Eliminator nosecone does NOT reflect the appropriate shoulder/nosecone thickness to match up to the original 1340 nosecone (oh, and payload tube connector as well, which also sported the appropriate specs to mate the two sections of heavy walled body tube of the original 1340).

That said, the method you described for 'centering' the motor tube inside the body tube may work. You might can peel some layers out of the inside of the existing Eliminator motor tube centering 'sleeve' to serve the same purpose.

I picked up 6-7 more Eliminators for for the same reason. ;)


Earl

Good point about the body tube thickness. I never considered that. I did consider peeling the existing centering ring, but what I would be left with would be slightly thicker than a couple of rings of typing paper. :rolleyes: :D I don't expect the new Estes 29mm engines to have the kick of the old Enerjet engines, so I think I'd be okay with the method I described, especially if I went with epoxy.

I used this method with my Enerjet 1340 and Nike Ram clones.

I too purchased several Eliminator kits during the Estes sale. I also purchased some HTC-13 tube couplers from Semroc. As in the Nike Ram instructions I will be gluing the coupler tube around the 29mm motor tube and then gluing this assembly into the ST-13/BT-56 body tube as the motor mount.

I have only flown my Enerjet-1340/Nike Ram clones on AeroTech E15-7 motors and did not have any issues.

If you are going to clone the 1340, use the thicker Series 125 Minimax tubing from Semroc. Then the tape on the 3" long Series 115 motor tube will be thinner. Extend it 1/2" out the back to accept motor retention tape. No installed thrust ring of course. Nothing wrong with tape as a "centering tube". The Enerjet 1340 had a 1/4" long rim on the red molded coupler. You could use a 3" long piece of Series 115 as a coupler and a 1/4" piece of Series 125 as the ring placed on the center of the coupler. Plywood plate to block it. The nose cone could easily be a custom Semroc or BMS cone to fit Series 125 tube like a red Enerjet 1340 part the shape of a Phoenix Bird cone.

Recommended power is 80 F 67 and 110 G 76. The Aerotech or USR 160 G80 seemed to be the marginal speed limit motor for the fin unit. But it could handle the regressive 320 H 90 just fine. USR D-Grain.

Don't clone it, duplicate it!

Historical Jerry

Unfortunately this one will have to go into the books as a clone. It was one of the rockets in the paint booth last weekend and up close it really looks rough. I tried to use as many of the donor Eliminator parts as I could, but the purple body tubes didn't take paint real well. Then again, a lot of the rockets I painted last week turned out like that. :mad: Anyway, I'm thinking this one will be finished this weekend, so I'll have it for the next cornfield launch. The 29mm flight should be entertaining if nothing else, and it was an Estes clearance cheapie, so I won't be out much if things don't work out.
Or if they do. :rolleyes: :D :cool:

i got lazy on a few of my 1340's and wrapped gloss white self adhesive monokote ahead of the fin can instead of painting the airframe and put my EnerJet decal over that. Sometimes I got a crease in the monokote but just twisted that side around to the launch lug side after much cursing and not wanting to peel it off so I wouldn't suggest that method if you need to keep the profanity down during the build. ;)

The old formula Krylon red and Valspar red look pretty good for the fin can but I prefer the Valspar really as I am heavy handed and it's very forgiving. I probably should have spent more time on mine getting the finishes really nice but that model and the 1340/20 build so quickly I always seem to rush building mine to get them flyable.

We have one more launch opportunity following this weekend at the end of March and then our field is closed until winter.

I'll bet those Estes E16 and F15 BP with the long delay would be great with a long streamer if you go 29mm.

:)

.

Finally got this to the point that it's ready for decals. I printed off the decals this weekend and shot them with two coats of Testors decal bonder, so I should have pics of the finished product later today. For a cheap-n-dirty clone it looks pretty good. I have an assortment of Estes 29mm BP engines, E16s in 6 and 8 second delay, and F15s in 6 and 8. Anyone want to venture an opinion as to whether I'd be best off going with the 6 or 8 second delay? I'm leaning toward 8 due to the near minimum diameter size of the motors.

I would go with the 8 second delay unless it is the 'large' payload section 1340.
in that case I would go with the 6, or maybe even 4 with a heavy payload.

No payload at all. This is just an Estes Eliminator tarted up to look the Enerjet part and with a 29mm motor mount installed.
Plans are for it to hit leadoff for me on Saturday, :cool:
Plans are not necessarily to recover it. ;) But I have a tiny nylon chute in it just in case.