TimothyG
Well-Known Member
Had a final conversation today with my advisor on some last minute details for planning my level 3 build and attempt this up coming fall. In order to both get help with my build if needed and to share what I"m doing in one location, I'm going to try and do a build thread on here.
Major weakness's in my plan. I don't know how to do a fin analysis for flow or flutter. My simulation skills are severely lacking. I'm recovering from health problems that limit my activity. I'm meh at welding aluminum but have friends that are artists in aluminum. My understanding of program is severely limited.
Strengths I can machine easier then I can eat or drive. I'm a college student with access to machines and facilities I wouldn't normally have access to for design, testing, and manufacturing. All my electronics and components have been spread out over the last year so I'm reasonably prepared and familiar with the components.
Rocket design is a 98mm minimum diameter rocket using head end deployment similar to the avalanche arrangement. Motor retainer will be integrated into the aluminum fincan and shock cord attached to eyebolt in forward closure of motor. Electronics sled will be a 3D printed unit with individual cell like locations for electronics and batteries with channels run through out for wiring retention and protection. Traditional all thread rod connecting the two bulkheads with bulkheads each having a pair of charge tubes. Main parachute will be housed in a packing tube inside of the nosecone or resting on forward bulkhead depending on packing testing in the coming weeks. I've already decided to do green flames fading to black forward section and thanks to sticker shock that has already been made a reality. Final flight of the airframe will hopefully be at blackrock if everything goes will on a CTI N green motor. If stickers survive that I'll display it at my university engineering atrium until graduation or longer. If they bubble or burn I'll re-vinyl the airframe and display.
Solidified plans.
Electronics, power, airframe, motors selection, parachutes and harness's, deployment, data.
For electronics for deployment I'm running a pair of RRC2+ altimeters that have already flown several times and have proven themselves reliable and easy to use. I will also have an eggtimer proton on board for data collection as this meets my requirements for planning my flights as I move up in motor size to better match my sim and actual altitude. Two camera's will be mounted into the same sled as other electronics to try and record my flights. I just finished playing around with my eggfinder tracker unit while on vacation and hope to get better with it during my shakedown flights. An ARS audible beacon for back up in case rocket lands somewhere awkward and out of site(example is in a wadi).
Power will be with lithium batteries all around of various mah sizes and voltages depending on device. Wiring will be restrained 100% on sled through printed channels in the sled.
My pie in the sky dream is to get my certification on a metallic or dark matter motor from Aerotech as I have certified on their motors so far and love them. My primary local vendor already has my motors on order and is looking out for them for me now so I"m not chasing motors the week before. The work up flights will be two different K flights at my local field one to test general subsonic air worthiness another on the K2000 to test the strength of the air-frame and altimeters. My advisor has requested an L flight so I'll also be flying at least one L1000 in this airframe before my level 3 attempt.
I'll be running a used fruity chute iris that I have if it's appropriately sized but this is to be determined after mass of fincan is more solidly known. I have existing collection of great condition harness's I've used before and that I trust. a single fruity 18" drogue from apogee will be used. then main at 2000ft altitude to allow GPS a longer time to reacquire and accurately broadcast before loosing it on landing.
I've previously made elongated charge cups out of aluminum and will be making some guntube style charge cups that I've seen here on the forum. I might make these charge tubes breach loadable with pre-prepaired ejection charges in rimmed cases with epoxied in ignitors.
I've had a bad history of using simulations and as such I'm hesitant to trust altitude predictions for this rocket until after I fly it on smaller motors and dial everything in. This is where the proton will come in handy as I hope to get three different altitude data points as well as velocity data to compare to the simulations in Open Rocket to better dial in the performance of my rocket. This will also be an opportunity to get comfortable with the wifi eggtimer system as well as the safety systems of the proton without actually having it hooked up to charges.
Flexible idea's/plans
Fin can plan currently has three design options.
I can do a welded aluminum fincan and have the aluminum stress relieved and heat treated after(expensive).
I can machine a multi piece aluminum fincan(This option is cheap and only costs me my time).
I can braze fins onto a tubing section(this option is doable on my own without assistance but I have the least experience in this.)
I've received solid permission from my advisor as well as several of the RSO's where I fly to use an aluminum fincan on this rocket on the condition that I produce the fincan myself with zero off the shelf parts and proceed with the planned work up flights.
Major weakness's in my plan. I don't know how to do a fin analysis for flow or flutter. My simulation skills are severely lacking. I'm recovering from health problems that limit my activity. I'm meh at welding aluminum but have friends that are artists in aluminum. My understanding of program is severely limited.
Strengths I can machine easier then I can eat or drive. I'm a college student with access to machines and facilities I wouldn't normally have access to for design, testing, and manufacturing. All my electronics and components have been spread out over the last year so I'm reasonably prepared and familiar with the components.
Rocket design is a 98mm minimum diameter rocket using head end deployment similar to the avalanche arrangement. Motor retainer will be integrated into the aluminum fincan and shock cord attached to eyebolt in forward closure of motor. Electronics sled will be a 3D printed unit with individual cell like locations for electronics and batteries with channels run through out for wiring retention and protection. Traditional all thread rod connecting the two bulkheads with bulkheads each having a pair of charge tubes. Main parachute will be housed in a packing tube inside of the nosecone or resting on forward bulkhead depending on packing testing in the coming weeks. I've already decided to do green flames fading to black forward section and thanks to sticker shock that has already been made a reality. Final flight of the airframe will hopefully be at blackrock if everything goes will on a CTI N green motor. If stickers survive that I'll display it at my university engineering atrium until graduation or longer. If they bubble or burn I'll re-vinyl the airframe and display.
Solidified plans.
Electronics, power, airframe, motors selection, parachutes and harness's, deployment, data.
For electronics for deployment I'm running a pair of RRC2+ altimeters that have already flown several times and have proven themselves reliable and easy to use. I will also have an eggtimer proton on board for data collection as this meets my requirements for planning my flights as I move up in motor size to better match my sim and actual altitude. Two camera's will be mounted into the same sled as other electronics to try and record my flights. I just finished playing around with my eggfinder tracker unit while on vacation and hope to get better with it during my shakedown flights. An ARS audible beacon for back up in case rocket lands somewhere awkward and out of site(example is in a wadi).
Power will be with lithium batteries all around of various mah sizes and voltages depending on device. Wiring will be restrained 100% on sled through printed channels in the sled.
My pie in the sky dream is to get my certification on a metallic or dark matter motor from Aerotech as I have certified on their motors so far and love them. My primary local vendor already has my motors on order and is looking out for them for me now so I"m not chasing motors the week before. The work up flights will be two different K flights at my local field one to test general subsonic air worthiness another on the K2000 to test the strength of the air-frame and altimeters. My advisor has requested an L flight so I'll also be flying at least one L1000 in this airframe before my level 3 attempt.
I'll be running a used fruity chute iris that I have if it's appropriately sized but this is to be determined after mass of fincan is more solidly known. I have existing collection of great condition harness's I've used before and that I trust. a single fruity 18" drogue from apogee will be used. then main at 2000ft altitude to allow GPS a longer time to reacquire and accurately broadcast before loosing it on landing.
I've previously made elongated charge cups out of aluminum and will be making some guntube style charge cups that I've seen here on the forum. I might make these charge tubes breach loadable with pre-prepaired ejection charges in rimmed cases with epoxied in ignitors.
I've had a bad history of using simulations and as such I'm hesitant to trust altitude predictions for this rocket until after I fly it on smaller motors and dial everything in. This is where the proton will come in handy as I hope to get three different altitude data points as well as velocity data to compare to the simulations in Open Rocket to better dial in the performance of my rocket. This will also be an opportunity to get comfortable with the wifi eggtimer system as well as the safety systems of the proton without actually having it hooked up to charges.
Flexible idea's/plans
Fin can plan currently has three design options.
I can do a welded aluminum fincan and have the aluminum stress relieved and heat treated after(expensive).
I can machine a multi piece aluminum fincan(This option is cheap and only costs me my time).
I can braze fins onto a tubing section(this option is doable on my own without assistance but I have the least experience in this.)
I've received solid permission from my advisor as well as several of the RSO's where I fly to use an aluminum fincan on this rocket on the condition that I produce the fincan myself with zero off the shelf parts and proceed with the planned work up flights.