Kip_Daugirdas
Well-Known Member
- Joined
- Jun 2, 2013
- Messages
- 385
- Reaction score
- 555
My first build thread on TRF! As winter fades I will be getting this rocket ready to fly once again and figured some of you might want to follow along and learn from my mistakes . AND KEEP ME FROM MAKING NEW ONES. I will add build pictures/write-ups as I have time.
How it started:
A few years ago I moved from Boston to Utah and decided to get back into flying given that Salt Lake is a half-day drive from Black Rock. Inspired by Aeropac's 100k flight in 2012 and that the largest motor casings I own are a 6G 98mm and 6G 75mm - I'd give my own interpretation of the 4" to 3" two-stager a try.
The rocket flew for the first time at Balls 24 but unfortunately the sustainer did not light for reasons I will explain later. Regardless, I recovered the stages in great shape and the camera payload worked as planned. Apogee was 31,000 ft and I'll chalk it up as a test flight.
Overall stats:
First stage
4" FWFG tubing
58" tall
7.94 lbs - dry (flight ready minus motor)
3 fins
Sustainer
3" FWFG tubing
5:1 VK FWFG
65.5" tall
6.98 lbs - dry (flight ready minus motor)
3 fins
Some of the goals for this project were:
- Vacuum bag all fin layups/reinforcements
- Avionics, payload, and interstage design/layout/machine code to be done in CAD (Creo 2.0) - in the case of a bad crash rebuilding/machining would not be a huge chore. Also helped me optimize layouts and test fit parts.
- Machine all G-10 bulkheads and av-boards using CNC
- 3D print some avionics components out of ABS
- Machine the aluminum transition of the interstage on the lathe
- Have two GoPros on-board. One taking video and the other taking timelapse pictures
- Control the 1-button on function of the GoPro using Arduino
- Design and build everything in the span of 3 months <- Go fever always bites!
THE FLIGHT!
First what I did wrong:
1.) Did not wire and e-match or setup a pyro channel in the event the second stage did not light. I added a 12 second delay on the sustainer primary apogee charges to account for exceeding the baro-sensor and accelerometer error during a nominal flight. A stupid mistake that cost me a 6" long zipper in the sustainer airframe.
2.) I selected the "flight state after" and "flight state before" radial buttons when programing the Easy Megas. DON'T DO THIS!!! This totally locked out second stage ignition despite meeting all other set criteria (velocity, angle from vert, altitude).
3.) I really rushed to put this project together by starting design/construction less than 3 months out from Balls. The month prior to launch I was already working every free moment I had and staying up until 2,3,4,5AM every night. If I had done a better job spreading this project out, I could've avoided mistakes #1, #2, abandoning my social life, loss of sleep, wasted N2501 motor etc. Lesson learned.
What went right:
1.) Perfect boost, rocket was 8 degrees off vertical when the sustainer was set to light at T+14 seconds and I could've let the sustainer coast a bit longer too.
2.) Recovery went on without a hitch (no damage minus sustainer zipper) with all charges firing and all parachutes deploying
3.) GPS lock maintained throughout the flight
4.) Payload performed really well - the Arduino activated GoPro worked perfectly. I got some great pictures and video from the flight.
5.) Rocket appears to have preformed better than simulated (RASAero predicted 28,000 ft for the sustainer no-light flight).
6.) The stack hit 1300 mph and the sustainer, acting as a boosted dart, flew to 31,000 ft.
7.) Low spin rate - good on board video
8.) 1.9 caliber stability margin, sustainer did not need any nose weight.
The photo uploader is not working great...so I will post what I can from the launch.
More to come soon!
How it started:
A few years ago I moved from Boston to Utah and decided to get back into flying given that Salt Lake is a half-day drive from Black Rock. Inspired by Aeropac's 100k flight in 2012 and that the largest motor casings I own are a 6G 98mm and 6G 75mm - I'd give my own interpretation of the 4" to 3" two-stager a try.
The rocket flew for the first time at Balls 24 but unfortunately the sustainer did not light for reasons I will explain later. Regardless, I recovered the stages in great shape and the camera payload worked as planned. Apogee was 31,000 ft and I'll chalk it up as a test flight.
Overall stats:
First stage
4" FWFG tubing
58" tall
7.94 lbs - dry (flight ready minus motor)
3 fins
Sustainer
3" FWFG tubing
5:1 VK FWFG
65.5" tall
6.98 lbs - dry (flight ready minus motor)
3 fins
Some of the goals for this project were:
- Vacuum bag all fin layups/reinforcements
- Avionics, payload, and interstage design/layout/machine code to be done in CAD (Creo 2.0) - in the case of a bad crash rebuilding/machining would not be a huge chore. Also helped me optimize layouts and test fit parts.
- Machine all G-10 bulkheads and av-boards using CNC
- 3D print some avionics components out of ABS
- Machine the aluminum transition of the interstage on the lathe
- Have two GoPros on-board. One taking video and the other taking timelapse pictures
- Control the 1-button on function of the GoPro using Arduino
- Design and build everything in the span of 3 months <- Go fever always bites!
THE FLIGHT!
First what I did wrong:
1.) Did not wire and e-match or setup a pyro channel in the event the second stage did not light. I added a 12 second delay on the sustainer primary apogee charges to account for exceeding the baro-sensor and accelerometer error during a nominal flight. A stupid mistake that cost me a 6" long zipper in the sustainer airframe.
2.) I selected the "flight state after" and "flight state before" radial buttons when programing the Easy Megas. DON'T DO THIS!!! This totally locked out second stage ignition despite meeting all other set criteria (velocity, angle from vert, altitude).
3.) I really rushed to put this project together by starting design/construction less than 3 months out from Balls. The month prior to launch I was already working every free moment I had and staying up until 2,3,4,5AM every night. If I had done a better job spreading this project out, I could've avoided mistakes #1, #2, abandoning my social life, loss of sleep, wasted N2501 motor etc. Lesson learned.
What went right:
1.) Perfect boost, rocket was 8 degrees off vertical when the sustainer was set to light at T+14 seconds and I could've let the sustainer coast a bit longer too.
2.) Recovery went on without a hitch (no damage minus sustainer zipper) with all charges firing and all parachutes deploying
3.) GPS lock maintained throughout the flight
4.) Payload performed really well - the Arduino activated GoPro worked perfectly. I got some great pictures and video from the flight.
5.) Rocket appears to have preformed better than simulated (RASAero predicted 28,000 ft for the sustainer no-light flight).
6.) The stack hit 1300 mph and the sustainer, acting as a boosted dart, flew to 31,000 ft.
7.) Low spin rate - good on board video
8.) 1.9 caliber stability margin, sustainer did not need any nose weight.
The photo uploader is not working great...so I will post what I can from the launch.
More to come soon!
Last edited: