dee
Active Member
- Joined
- Sep 19, 2024
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Hi! I'm new here and just wanted to ask a few questions. I'm a total beginner so I apologise if these are too basic or obvious.
I need to design a model rocket that is less than 180 cm in length and is capable of carrying a 1 kg payload, deploying it at 1km and then safely landing after.
So my questions are:
1. Is there a particular equation to use when designing the nosecone? I found a video using FreeCAD to design nosecones and have currently made an elliptical nosecone using our required dimensions (length and diameters). Is there a way to check if it'll perform well?
2. We started out with an OpenRocket simulation and are using the dimensions from the final optimised simulation to do the CAD modelling. How are the dimensions of the tail cone determined? What are the parameters that influence the design of the tail cone?
3. Similarly, how does one go about designing the fins? We have a trapezoidal set from our OpenRocket simulation that provides decent stability. Do we just convert it to CAD directly? How can we test whether it's a good design?
For context, the OpenRocket simulation gave favourable results, we got the desired velocity, weight and apogee which is why we decided to replicate that design in our CAD models. Right now, I'm planning to use the nosecone from FreeCAD and then build the rest of the body tube on SolidWorks including the couplers, bulkheads and the engine mount - all as separate parts so I can insert the payload and avionics bays later. Is that a good approach or is there a better alternative?
I've come across several equations but I can't seem to know where I should start from or what I should be looking for or how I can use them in the designing process. I've also read about the 5:1 ratio for the tail cones and would love to know how these results are arrived at and their significance.
I'd appreciate any help and advice regarding the designing process in general.
Thank you.
I need to design a model rocket that is less than 180 cm in length and is capable of carrying a 1 kg payload, deploying it at 1km and then safely landing after.
So my questions are:
1. Is there a particular equation to use when designing the nosecone? I found a video using FreeCAD to design nosecones and have currently made an elliptical nosecone using our required dimensions (length and diameters). Is there a way to check if it'll perform well?
2. We started out with an OpenRocket simulation and are using the dimensions from the final optimised simulation to do the CAD modelling. How are the dimensions of the tail cone determined? What are the parameters that influence the design of the tail cone?
3. Similarly, how does one go about designing the fins? We have a trapezoidal set from our OpenRocket simulation that provides decent stability. Do we just convert it to CAD directly? How can we test whether it's a good design?
For context, the OpenRocket simulation gave favourable results, we got the desired velocity, weight and apogee which is why we decided to replicate that design in our CAD models. Right now, I'm planning to use the nosecone from FreeCAD and then build the rest of the body tube on SolidWorks including the couplers, bulkheads and the engine mount - all as separate parts so I can insert the payload and avionics bays later. Is that a good approach or is there a better alternative?
I've come across several equations but I can't seem to know where I should start from or what I should be looking for or how I can use them in the designing process. I've also read about the 5:1 ratio for the tail cones and would love to know how these results are arrived at and their significance.
I'd appreciate any help and advice regarding the designing process in general.
Thank you.