Estes Goblin Fin Can by Aslansmonkey

Last crawled date: 3 years, 1 month ago

I had some spare BT-55 tube laying around and an extra Goblin nose cone (See thing https://www.thingiverse.com/thing:3073567/files) and decided I had almost everything I needed to make my own Goblin. So I modified the fin can from ellipricaloptician's model rocket kit to make this one.
A couple notes...
1) I thickened the fins a little from the prototype shown in my photo. One of the bottom tips on my prototype broke off (just a little bit), so I clipped the rest to match. The thicker fins on the included file should work better.
2) I've not flown this yet, or checked it for stability. Weight may need to be added to the nose to make it stable. Look up on the internet how to do this if you don't know how.
3) As both Estes and Semroc produce "Goblin" kits at this time, I'm pretty sure the decals are likely copyrighted, so I am not included those. Do a Google Search, you'll find them just as easy as I did. I added extra bats to the file I found. They're handy for covering up blemishes on the paint.
4) I used the "best guess" method for scaling the fins. That is to say I looked at a photo of the original, notices that the fin was about two body tubes wide, and scaled the fins accordingly. I do not own an original Goblin at this time so I have no idea how close I got. But it looks good enough to me. They should be the same shape.
Ok, edit to #4 here as I just spoke to my brother, who is making 2 Goblins from scratch using the original plans. He makes them with plywood fins because he likes to put E's and F's in them. He's making 2 because he loses them because he puts E's and F's in them. According to him the original root edge on the Goblin fin is 2". Mine are a little over 2 1/4", so they're a little oversize. I apologize to all the purists out there for this but if you're that much of a purist, go buy the original kit, they still make them.
Edit to the edit on #4. I had time today so I resized the fins closer to where they should be. I've included them as the "Corrected" fins but left the original in case you want to print the slightly oversized ones for bonus stability.
5) You'll need the nose cone linked above (I used the "Base2" base for this nose) and the retainer from ellipticaloptician's original kit (see the thing this is a remix from) to complete this kit.
6) Oh, and you'll need a shock cord and chute, of course.
EDIT 10/22/2018: Added a notch inside for the shock cord to run through that was missing in the original files.
EDIT 5/8/2019: Added a version of the "corrected" fins that fit an Estes E-motor. For really high flights.
FLIGHT REPORT
Flew the larger of the two on a D12-5 today. The flight itself was perfect, but the nose cone and streamer separated at apogee and fell separately. The body tumbled down and a nice sedate pace, however and I was able to recover everything intact. But I may have to use thicker Kevlar shock cord.