Help with rocket ID
 

This is a minimum diameter 18mm bird, 14.125" long, streamer recovered, with spin fins. No identifying marks other than a piece of tape that says "Sound Barrier Backup". It was an Ebay bird and I'm trying to find out if it was a commercially available kit, or if it was just a bird tossed together for max altitude and duration. :confused:

Bill,

I flew some CMR kits back in the 70's. That looks like the upper stage of the two stage CMR Hyper rocket that I had back then that was a payload model and had thin plywood fins. Are the fins on your model plywood?

Give the nose cone a little squeeze and see it it's that really lightweight plastic that CMR used and that's probably it. Pull the nose cone out and does the shoulder have a small pinhole in the center to attach a thread for attachment to the shock cord?

I flew mine with the pop lug and even on 1/2A and A motors in both stages it would fly completely out of sight until ejection. I only recovered it because I used full length 10 foot CMR mylar streamers for recovery.

:)

.

:cool: Thanks, Steve. I looked through the catalogs on Ninfinger last night and found a couple that were close to what I was looking for, but they seemed to be just a little off. I never considered the possibility that it was originally a two-stager. The lightweight nose cone would definitely seem to point to a CMR bird, and was something I meant to mention in the description. It's very light and connected to the shock cord by a string through the bottom of the cone.

I just noticed Scott has the plans for it you may be able to compare with some of the dimensions here

http://www.oldrocketplans.com/cmr/cmrC2/cmrC2.htm

The bottom stage was 3" so that would put your upper stage length about where you referenced.

I had the ELO and the EFFY too. CMR used that fin design a lot but the nose cones in CMR kits were quite unique in design and shape. I botched a couple using too much glue they were so thin they would melt when joining the shoulder to the cone. I have a picture of the upper stage of my ELO in an old pic from 1978.

Nice find by the way ..... although I'd be inclined to snap the fins off and glue them on straight!

:D

.

I'm stumped as to what it might be, but I must say those fins look like they were intended to be canted. In this configuration they would definitely spin the rocket.

This one doesn't have the payload section mentioned in the instructions, but it mentions that it can be flown without one. The lack of a pop lug setup has me wondering, though. As for the fins, I like them in this setup. They should cut down on the altitude a bit and make it flyable at B6-4 Field on a 1/2A. This weekend is shot because of the Big Top Festival, but I can welcome October in the right way next weekend.

Hopefully better than my recently completed Spin Fin clone. That one was gone so fast I couldn't tell if it spun or not. :rolleyes: :D

After poring over the CMR catalog at Ninfinger, I've decided that what I have is a CMR Effy. What threw me was the catalog description, "High efficiency single-stage starter kit with all the features of the regular kits except the "pop" launch lug." I read it wrong and thought that it said that it included the "pop" lug. It's listed at 15" in length, while my rocket is 14"+. Not sure how closely the tolerances were followed at CMR, but I know that FSI stats varied from one kit to another.

Bill it does look a lot like the EFFY. I had one of those too I just don't have pictures of that model in particular.

I do remember losing the EFFY after just one or two flights. I had painted mine all red but it flew so high even with a mylar streamer it drifted away .....

:(

.

I'm thinking 1/2A to start. I doubt that the field will be big enough to try an A8.