Haven't even been to a launch since ~2007 when the NRVR prefecture was created and I attended their first launch. If anyone that was in attendance, you may remember me as the grill operator - having caused a massive grease fire! Anyhow, I was in awe so it was only a matter of time before I tried my hand.
I went with a 5.5 Goblin and tried to take plenty of pictures along the way but did miss some steps along the way
Started off with a dry fit - no surprises there.
I had to do a little sanding to get the fin width correct for the motor mounts but they fit like a glove after that. I tacked the mmt rings in place with some CA glue. After watching an apogee instructional, I was inspired to flood the fin tube joint with epoxy. I used 30 minute BSI since that's what I had plenty of that on hand from mid-power builds.
I filled the spirals of the body tube with elmer's wood filler. Precision was not the name of the game on this one - which I regretted come time to sand. I should have done the fins at this time as well but lesson learned. Didn't get a picture of it after sanding.
Finally time to insert it into the body. There was a quite a buldge at the bottom ring so that would need to be remedied.
I picked up some West System 406 filler for all fillets moving forward. Let's just say that my first two were a bit liberal and sloppy in application.
Made some clamping blocks to get the body flush with the rings.
I did a much better job on the wing fillets. I taped off the area around the fins and used a large socket dipped in isopropyl alcohol to get the fillets smooth.
Finally time for primer
I wasn't happy with the roughness of the fillets so I hit them with Bondo glazing putty and a boat load of sanding. Then more sanding. It was awful.
I couldn't quite get rid of the nose ridge from sanding so I did it as well.
I finally realized I'd have to hit the fins with filler as well to get rid of those grains.
More primer - looking way better!
Time to put on the matte black finish coat and the rings.
Not shown are the 4x attempts at finishing the nose cone with what was ultimately the equivalent of a scratch-off ticket. Sanding and an alcohol rub-down were not enough. It wasn't until I water-boarded it with acetone that I finally got the pain to stick!
At this point, I decided I wanted a fancy motor retainer so I had to dremel off a ton of epoxy and installed that.
Next I built the mmt adapter using JB weld. I also 3d printed a ring to go on the face of the mmt because it seemed crazy to me that a single ring with no fillets mounted flush with the tube end (per instructions) was all that would be holding the motor back. It was a little extra peace of mind even if PLA has little heat tolerance.
The wooden retainer ring that fits inside the 54mm retainer barely allows the retainer to twist on so now I need an offset retainer to accomplish the task. Once again, I 3d printed something. This is the part I'm most concerned with for the launch. I CA glued aluminum foil on the backside to help stop some heat transfer but I don't know how much heat the retainer is exposed to. One alternative I thought of is 3d printing a mold to make the same retainer out of JB Steel Stik. Would love some feedback on this.
Had to give it a name and since my other passion is Jiu Jitsu, I couldn't pass up the opportunity to name it after my favorite dirty move - the Wrist Lock! I have to admit that I'm embarrassed by my homemade stencil job. I did not expect the clear coat to stick to my stencil like it did so the Gears of War font looks rather organic from all the tearing. I plan on redoing it before launch.
I'll be flying it on a Cesaroni I-175 at the next NC Rocketry, Bayboro launch on the 27th and 28th.
Hope y'all enjoyed this. Feedback is always welcome and maybe I'll see some of you at the launch
I went with a 5.5 Goblin and tried to take plenty of pictures along the way but did miss some steps along the way
Started off with a dry fit - no surprises there.
I had to do a little sanding to get the fin width correct for the motor mounts but they fit like a glove after that. I tacked the mmt rings in place with some CA glue. After watching an apogee instructional, I was inspired to flood the fin tube joint with epoxy. I used 30 minute BSI since that's what I had plenty of that on hand from mid-power builds.
I filled the spirals of the body tube with elmer's wood filler. Precision was not the name of the game on this one - which I regretted come time to sand. I should have done the fins at this time as well but lesson learned. Didn't get a picture of it after sanding.
Finally time to insert it into the body. There was a quite a buldge at the bottom ring so that would need to be remedied.
I picked up some West System 406 filler for all fillets moving forward. Let's just say that my first two were a bit liberal and sloppy in application.
Made some clamping blocks to get the body flush with the rings.
I did a much better job on the wing fillets. I taped off the area around the fins and used a large socket dipped in isopropyl alcohol to get the fillets smooth.
Finally time for primer
I wasn't happy with the roughness of the fillets so I hit them with Bondo glazing putty and a boat load of sanding. Then more sanding. It was awful.
I couldn't quite get rid of the nose ridge from sanding so I did it as well.
I finally realized I'd have to hit the fins with filler as well to get rid of those grains.
More primer - looking way better!
Time to put on the matte black finish coat and the rings.
Not shown are the 4x attempts at finishing the nose cone with what was ultimately the equivalent of a scratch-off ticket. Sanding and an alcohol rub-down were not enough. It wasn't until I water-boarded it with acetone that I finally got the pain to stick!
At this point, I decided I wanted a fancy motor retainer so I had to dremel off a ton of epoxy and installed that.
Next I built the mmt adapter using JB weld. I also 3d printed a ring to go on the face of the mmt because it seemed crazy to me that a single ring with no fillets mounted flush with the tube end (per instructions) was all that would be holding the motor back. It was a little extra peace of mind even if PLA has little heat tolerance.
The wooden retainer ring that fits inside the 54mm retainer barely allows the retainer to twist on so now I need an offset retainer to accomplish the task. Once again, I 3d printed something. This is the part I'm most concerned with for the launch. I CA glued aluminum foil on the backside to help stop some heat transfer but I don't know how much heat the retainer is exposed to. One alternative I thought of is 3d printing a mold to make the same retainer out of JB Steel Stik. Would love some feedback on this.
Had to give it a name and since my other passion is Jiu Jitsu, I couldn't pass up the opportunity to name it after my favorite dirty move - the Wrist Lock! I have to admit that I'm embarrassed by my homemade stencil job. I did not expect the clear coat to stick to my stencil like it did so the Gears of War font looks rather organic from all the tearing. I plan on redoing it before launch.
I'll be flying it on a Cesaroni I-175 at the next NC Rocketry, Bayboro launch on the 27th and 28th.
Hope y'all enjoyed this. Feedback is always welcome and maybe I'll see some of you at the launch
