5thDay
Well-Known Member
I have had to scale back my builds significantly for a few reasons and sadly that ment mothballing the "big" Soyuz project for a while. As a positive, having a 9ft rocket shell hanging from my ceiling is a piece of decorating I am really proud of.
This last week however when inventorying and cleaning out my tubes I had some ideas I wanted to send skyward. Below is a basic description, some features and a question of opinion regarding my "fin" idea for stage 2.
The Proton never really impressed or inspired me much until I considered it as a build project. The psuedo-booster look however is more interesting when considering NOT tracking 7+ objects descending and when the 6 engine cluster can easily be treated as a basic first stage of a simple 2 stage rocket. It also put to good use the variety of thick walled tubes I have of various sizes that telescope with other tubes I have accumulated.
Stage I core is made from 68mm 4mm wall tube with 6 "booster" tubes arranged around it. Stage 2 core leading all the way to the shroud is 59mm tube that is also 4mm wall. These sturdy tubes are nice to work with but don't make it into material selection often due to their excessive weight. Each stage joins the stage above it via a thrust ring or collar in a 'push up from underneath' concept that I think will help immensely with drag seperation and nosecone ejection. That will be looked at closely during first test flights with a dummy load in stage 2 and nylon screws holding the stages together.
My flight plan ultimately is launching with six E12-4, clustered and mounted into the external tubes via 29-24mm adapters and engine blocks. Utilizing an extremely simple 556 timer in monostable configuration, stage 2 hot stage starts a H180-10 just tenths of a second before the E cluster falters in accelerating. This checks a couple boxes for me in a progressively more challenging list of flight profiles to complete. BP to APCP staging, cluster as stage 1 and airstarting a HP motor.
As is often the case with scale or near scale models (this is not scale accurate or the same scale as my smaller Soyuz)... I had to consider stability of the entire rocket and of stage 2 alone. Gas Stabilization is something I want to attempt eventually but not at this impulse level and acrylic fins would be overkill for this sized rocket IMO. What I have come up with, I think is clever, and simulates well in OpenRocket.
As I try to demonstrate in the photos below, I want to attach the first stage nosecones to the second stage external 'thrust collar'.
After separating the nosecones would remain and function as fins for stage 2. Stage 1 would have 3 of 6 tubes loaded with small parachutes that will deploy on descent with their ejection charges. Having the first stage central tube open gives me more confidence in the airstart and I simply like the way multi-chute descents look.
Currently the nosecone/fins are simply HappyMeal material but will be fiberglass coated to hold their shape. I did consider leaving the nosecones attached to stage 1 tubes, but having them pass through rings attached to stage 2 which would function like short tube fins but, the leaning in geometry of these cones didnt work well with that idea and I have a suspicion that I will get more CP movement with cones. Who cares to offer predictions or thoughts on this design?
**My baby Soyuz came out of storage for repairs in order to fly the same day as the Proton. It was never finished as a staged or clustered rocket and only flew once on a single F72 as a stability test. I may add a single C motor to each booster just for effect but will likely keep everything connected as a single stage rocket. Photo for size and detail comparison of my Baikonur fleet added last.
This last week however when inventorying and cleaning out my tubes I had some ideas I wanted to send skyward. Below is a basic description, some features and a question of opinion regarding my "fin" idea for stage 2.
The Proton never really impressed or inspired me much until I considered it as a build project. The psuedo-booster look however is more interesting when considering NOT tracking 7+ objects descending and when the 6 engine cluster can easily be treated as a basic first stage of a simple 2 stage rocket. It also put to good use the variety of thick walled tubes I have of various sizes that telescope with other tubes I have accumulated.
Stage I core is made from 68mm 4mm wall tube with 6 "booster" tubes arranged around it. Stage 2 core leading all the way to the shroud is 59mm tube that is also 4mm wall. These sturdy tubes are nice to work with but don't make it into material selection often due to their excessive weight. Each stage joins the stage above it via a thrust ring or collar in a 'push up from underneath' concept that I think will help immensely with drag seperation and nosecone ejection. That will be looked at closely during first test flights with a dummy load in stage 2 and nylon screws holding the stages together.
My flight plan ultimately is launching with six E12-4, clustered and mounted into the external tubes via 29-24mm adapters and engine blocks. Utilizing an extremely simple 556 timer in monostable configuration, stage 2 hot stage starts a H180-10 just tenths of a second before the E cluster falters in accelerating. This checks a couple boxes for me in a progressively more challenging list of flight profiles to complete. BP to APCP staging, cluster as stage 1 and airstarting a HP motor.
As is often the case with scale or near scale models (this is not scale accurate or the same scale as my smaller Soyuz)... I had to consider stability of the entire rocket and of stage 2 alone. Gas Stabilization is something I want to attempt eventually but not at this impulse level and acrylic fins would be overkill for this sized rocket IMO. What I have come up with, I think is clever, and simulates well in OpenRocket.
As I try to demonstrate in the photos below, I want to attach the first stage nosecones to the second stage external 'thrust collar'.
After separating the nosecones would remain and function as fins for stage 2. Stage 1 would have 3 of 6 tubes loaded with small parachutes that will deploy on descent with their ejection charges. Having the first stage central tube open gives me more confidence in the airstart and I simply like the way multi-chute descents look.
Currently the nosecone/fins are simply HappyMeal material but will be fiberglass coated to hold their shape. I did consider leaving the nosecones attached to stage 1 tubes, but having them pass through rings attached to stage 2 which would function like short tube fins but, the leaning in geometry of these cones didnt work well with that idea and I have a suspicion that I will get more CP movement with cones. Who cares to offer predictions or thoughts on this design?
**My baby Soyuz came out of storage for repairs in order to fly the same day as the Proton. It was never finished as a staged or clustered rocket and only flew once on a single F72 as a stability test. I may add a single C motor to each booster just for effect but will likely keep everything connected as a single stage rocket. Photo for size and detail comparison of my Baikonur fleet added last.
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