Loc Goblin Thread

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I'd just get a new stiffy coupler and rebuild the top section with some fresh pieces. Really too bad when that happens. I see why guys use plastic rivets on the big stuff.
 
I told him we should make Goblin Saucers... Mine broke off right above the fin unit after a failed deploy.
Yes I saved the fin unit. No I haven't figured out how to make the saucery part to cover the fins yet...
 
In all honesty, a little elbow grease and a palm sander and you should be able just to clean up the whole motor-mount/fin can assembly and slide it into a new tube. Have a new rocket to fly in a couple of hours, lol.

Love the saucer idea, too! That would be awesome.
 
On the subject of drag separation - I suffered a catastrophic separation at Midwest Power. My first flight was on a J275 and it was picture perfect. So, naturally I had to try a K185 long burn :) Well, about 2 seconds into an 8 second burn the nosecone popped off and the rocket shredded. It seems odd to me that I’d suffer a separation on my second flight and at much lower altitude and speed than the J275, but that’s my best guess as to what happened. At any rate, here’s my before and after photos for your viewing pleasure(?).

View attachment 437499

View attachment 437498

The good news is the fin can is completely solid still and I can probably do something with it - still have to figure out what exactly. Any ideas?

And a replacement Goblin is on order already 😁

~Dave~
Yeah, I saw that happen. It was painful to witness.
As to it's next life, maybe use it as a booster? Two stage Goblin for twice the fun... :p
 
On the subject of drag separation - I suffered a catastrophic separation at Midwest Power. My first flight was on a J275 and it was picture perfect. So, naturally I had to try a K185 long burn :) Well, about 2 seconds into an 8 second burn the nosecone popped off and the rocket shredded. It seems odd to me that I’d suffer a separation on my second flight and at much lower altitude and speed than the J275, but that’s my best guess as to what happened. At any rate, here’s my before and after photos for your viewing pleasure(?).

View attachment 437499

View attachment 437498

The good news is the fin can is completely solid still and I can probably do something with it - still have to figure out what exactly. Any ideas?

And a replacement Goblin is on order already 😁

~Dave~
What size vent hole did you have in the bottome/booster?
 
Friction fit will be fine at lower altitudes. I would not recommend shear pins unless you plan to ground test.
Russ
 
What size vent hole did you have in the bottome/booster?

I believe I had just one 5/32" vent hole, about 1" below the shoulder of the nosecone.

My working hypothesis is that the longer casing for the K185 (54-1706) caused me to place the nomex against the vent hole. I wasn't using shear pins, so it's always possible the nosecone fitting was somehow different between the two flights. I tested the friction fitting before the flight and it was "lift the rocket" tight. I doubt I'll ever know for sure. At least the fin can is still in good shape :)
 
I had my eyes on the 4” goblin for a while, but with little time to build and keep wife happy, decided to go with a pre built FiberMax for now.
 
Really tempted to get the LOC Goblin. Digging the idea of square fins and wood glue. Fast and easy build is quite attractive.
If you use epoxy it is a tank; I have launched everything from H's to J's. It is now my test platform and just a workhorse. The choice of 29mm, 38mm, and 54mm allows for a launch as long as a motor vendor is on the field.
 
What fillet size y'all using? Most pics I've seen look like the internal fillets are pretty thick...tongue depressor-ish? External fillets seem smaller -- presumably because the fin can is so stout.
 
If you use epoxy it is a tank; I have launched everything from H's to J's. It is now my test platform and just a workhorse. The choice of 29mm, 38mm, and 54mm allows for a launch as long as a motor vendor is on the field.

Use wood glue and it’s still a tank. I’ve flown mine on small K motors. All Titebond II construction.
 
I just made it through all nine pages of this thread after skipping over past it many many times, and I was most impressed by the use of Ultracote to eliminate that entire painting process. Looks like I now have to go on YouTube and learn all about how to apply Ultracote.
I'm rather amazed that I have never seen a thread on this before where you would think that this would be one of the most highly used techniques to eliminate all of the painting in rocketry. There must be something really disadvantageous to do it this.
 
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I just made it through all nine pages of this thread after skipping over past it many many times, and I was most impressed by the use of Ultracote to eliminate that entire painting process. Looks like I now have to go on YouTube and learn all about how to apply Ultracote.
I'm rather amazed that I have never seen a thread on this before where you would think that this would be one of the most highly used techniques to eliminate all of the painting in rocketry. There must be something really disadvantageous to do it this.

Hey Marty,

I don't find it disadvantageous, but it's probably not for everybody. I paint some rockets, I cover others. Most of my paper/ply rockets are covered nowadays.

Though the forum reformat and Photobucket changes wiped out some of the photos, here's a "how to" thread I did on covering rockets: Applying Monokote or Ultracote Heat Shrink Film to rockets | The Rocketry Forum

Cheers, Eric
 
I just made it through all nine pages of this thread after skipping over past it many many times, and I was most impressed by the use of Ultracote to eliminate that entire painting process. Looks like I now have to go on YouTube and learn all about how to apply Ultracote.
I'm rather amazed that I have never seen a thread on this before where you would think that this would be one of the most highly used techniques to eliminate all of the painting in rocketry. There must be something really disadvantageous to do it this.

There's a BIG disadvantage to Ultracoat IMHO...It's largely because of ding dongs such as myself. I tend to abuse the finish of my rockets. I try to be careful but I fear that putting in the extra work and money (although I don't know that it's much more expensive than paint) to make it look so pretty means it's doomed to scratching and the like. Flying the rocket is not the issue - its the transportation or road rash as its called. Currently, I am working on creating good rocket transport habits but I am not quite there where I want to ultracoat everything - yet. I may get there someday. It's a process.
 
There's a BIG disadvantage to Ultracoat IMHO...It's largely because of ding dongs such as myself. I tend to abuse the finish of my rockets. I try to be careful but I fear that putting in the extra work and money (although I don't know that it's much more expensive than paint) to make it look so pretty means it's doomed to scratching and the like. Flying the rocket is not the issue - its the transportation or road rash as its called. Currently, I am working on creating good rocket transport habits but I am not quite there where I want to ultracoat everything - yet. I may get there someday. It's a process.

You mean I’m not the only one who just chucks a bunch of rockets into the back of the car for the trip to the launch?
Good to know… :D
 
Not for club launches. For traveling to AirFest, I try to put covers between the layers. They don’t always stay in place. But when they’re 200’ out, you don’t notice the scratches. And after they land, they’re gonna get more scratches…
 
There's a BIG disadvantage to Ultracoat IMHO...It's largely because of ding dongs such as myself. I tend to abuse the finish of my rockets. I try to be careful but I fear that putting in the extra work and money (although I don't know that it's much more expensive than paint) to make it look so pretty means it's doomed to scratching and the like. Flying the rocket is not the issue - its the transportation or road rash as its called. Currently, I am working on creating good rocket transport habits but I am not quite there where I want to ultracoat everything - yet. I may get there someday. It's a process.

This brings up one of those maxims of rocketry: The nicer the finish, the more likely the rocket is to get drug across the cornfield by surface winds, thus ruining said nice finish!
 
Ya'll don't even wrap them in a blanket or anything?

I am now. Didn't used to. Been grabbing bath towels my wife and I would typically toss or donate and now have a pile of them to lay between the rockets so they aren't rubbing against each other making mini rockets.
 
I use an old stinky bed comforter to wrap my large rockets. LPR's simply go back into the shipping box they came in, with the paper packing.
 
I am building the Loc 4" Goblin to do L1 cert (on an H238T).
Reading through this thread again and noticed the decal sheet I got has 7 Bats on it but only one number '3'. I like the bats and not putting the '3' on. I also painting the black band.
I build the MM internal, front two CR on MMT and epoxy into BT. Then add fins and internal and external fillets with rear CR removable. I used the epoxy sparingly and fillets are 1/8" radius Rocketpoxy so don't think epxoy added too much weight.
Paint is florescent orange (Createx) and I be putting the decals on tonight (will take and post picture tonight) then gloss clear coat.
Maiden flight is planned for next Saturday on a G76T. Planning L1 flight in June or if too windy July.
 
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