scsager
Slightly burned-out old guy
- Joined
- Apr 24, 2010
- Messages
- 1,779
- Reaction score
- 80
I Scratch built "Cherry Bomb" in the fall of 2010. It's made from 3 sections of 15" BT80 - the cheap stuff from Hobbylink.com. The plastic nose cone came from Appogee. The fins were hand cut from 1/8" lite ply with the lower fin an Equilateral Triangle.
It crashed on its first flight at Bong on an F40-7. A very late ejection caused the chute to open about 5 feet off the ground.
I rebuilt it, shortening it about 6 inches, and adding a baffle and payload section.
It flew with a keychain camera at the sod farm in July 2013. We had what could only be described as a "freak accident". When it landed, the upper body tube impaled itself on one of the rail buttons.
Repaired once again, and I added an Aeropack retainer and some new vinyl Stickershock23.com graphics, I decided to fly her again today.
Big turn-out today at Bong. Lots of Boy Scouts (in uniform even). The Wildman was serving up steaks for lunch - I don't know how he gets them so tender... Fantastic
I loaded up Cherry Bomb with an Aerotech G79-10 single use motor. I have several of these in my motor box. Today I had to peel the label off the motor to get it in the tube. I wasn't too concerned about that, sometimes the motor or the tube is just a bit out of spec.
Perfect flight on the G79 and the split fins made a noticeable loud whistle after motor burnout. Nice recovery on a homemade rip stop nylon chute maybe 200-300 feet behind the pad.
Beautiful blue skies, almost no wind and temps in the 70's. What a nice day, "I think I’ll fly it again".
A bit of smoke, and it forcefully spit the igniter this time. No problem, I've got more igniters. As I approached the pad I saw something unusual. The upper section of the rocket was raised up from the fin can about a half inch. I always make sure I have the right fit to prevent drag separation - so this seemed weird. I could have pulled the motor to check things out, but I didn't. I simply put the nose section back in place and replaced the igniter. You know what they say about hindsight.
This time a bit of smoke, then BLAM the nose and laundry eject on the pad. Flames from the top and bottom - more from the top.
First time I ever had to put out a pad fire. Not a grass fire - just my rocket burning on the rail. :shock:
Nosecone, laundry, nomex, kevlar - all fine. Fin can = toast.
I couldn't get the motor out of the motor tube. Pulling on it with a pliers - wouldn't budge.
When I got home - I sliced away the fin can to find out more.
There is a crack running the length of the plastic case. The forward closure is missing. You can see the forward end of the motor has swelled - so much that I can't get the Aeropack retainer off without cutting the motor.
You can also see a spiral shaped chunk of the top of the motor is missing. I believe the Forward end of these motors - with the yellow hexagon charge well - are actually screwed and epoxyed into the case.
I used a Twiggy starter from Quick Burst all three times. The Twiggy went into the motor easily with no binding, so I don’t believe that was the cause of the over pressurization.
A MESS Report has been filed. I'll try to contact Areotech on Monday to see about a warranty replacement .
It crashed on its first flight at Bong on an F40-7. A very late ejection caused the chute to open about 5 feet off the ground.
I rebuilt it, shortening it about 6 inches, and adding a baffle and payload section.
It flew with a keychain camera at the sod farm in July 2013. We had what could only be described as a "freak accident". When it landed, the upper body tube impaled itself on one of the rail buttons.
Repaired once again, and I added an Aeropack retainer and some new vinyl Stickershock23.com graphics, I decided to fly her again today.
Big turn-out today at Bong. Lots of Boy Scouts (in uniform even). The Wildman was serving up steaks for lunch - I don't know how he gets them so tender... Fantastic
I loaded up Cherry Bomb with an Aerotech G79-10 single use motor. I have several of these in my motor box. Today I had to peel the label off the motor to get it in the tube. I wasn't too concerned about that, sometimes the motor or the tube is just a bit out of spec.
Perfect flight on the G79 and the split fins made a noticeable loud whistle after motor burnout. Nice recovery on a homemade rip stop nylon chute maybe 200-300 feet behind the pad.
Beautiful blue skies, almost no wind and temps in the 70's. What a nice day, "I think I’ll fly it again".
A bit of smoke, and it forcefully spit the igniter this time. No problem, I've got more igniters. As I approached the pad I saw something unusual. The upper section of the rocket was raised up from the fin can about a half inch. I always make sure I have the right fit to prevent drag separation - so this seemed weird. I could have pulled the motor to check things out, but I didn't. I simply put the nose section back in place and replaced the igniter. You know what they say about hindsight.
This time a bit of smoke, then BLAM the nose and laundry eject on the pad. Flames from the top and bottom - more from the top.
First time I ever had to put out a pad fire. Not a grass fire - just my rocket burning on the rail. :shock:
Nosecone, laundry, nomex, kevlar - all fine. Fin can = toast.
I couldn't get the motor out of the motor tube. Pulling on it with a pliers - wouldn't budge.
When I got home - I sliced away the fin can to find out more.
There is a crack running the length of the plastic case. The forward closure is missing. You can see the forward end of the motor has swelled - so much that I can't get the Aeropack retainer off without cutting the motor.
You can also see a spiral shaped chunk of the top of the motor is missing. I believe the Forward end of these motors - with the yellow hexagon charge well - are actually screwed and epoxyed into the case.
I used a Twiggy starter from Quick Burst all three times. The Twiggy went into the motor easily with no binding, so I don’t believe that was the cause of the over pressurization.
A MESS Report has been filed. I'll try to contact Areotech on Monday to see about a warranty replacement .
Last edited:
