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SteveA63

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I just upgraded yesterday from 9 and was wondering if anyone has been using 10 for awhile and what are your thoughts?
 

Mike Haberer

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Not too different from V9. They cleaned up the code so they can maintain and upgrade it better going forward. The biggest updates are the engine files and some of the component files. It basically works the same.
 

Dan Griffing

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Here’s a general RockSim10 question.

Is there a way to override the calculated component weight on general components that originated as databaseloaded parts like nosecones, airframes, couplers and motor mounts?

I have several kits where the actual component weights don’t match the RockSim component weights.

One of the first things I do for every kit I build is to update the RockSim design with the actual component weights to see how it affects the design’s simulation motor set for the prospective motors.

For example, my modified Apogee Peregrine has significant weight differences with every component.

The individual “calculated” component weight for each component isn’t updated when you modify the component override weight, CG, and check the box.

Its irritating that the only way to determine if the override is working correctly is to use a calculator on the before and after overall rocket weight. This gets old really fast when you’re modifying all of the weights in the RockSim design of a kit or want to determine where the weight discrepancy is.
 

Dan Griffing

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Here’s a RockSim10 subassembly question.

When modifying the motor mount in a loaded airframe subassembly, how can I prevent all of the motor simulation data sets from losing their motor mount information.

I have comparison designs that test against a common set of 30-50 motors, and it becomes really tedious to have to edit the simulations for 30-50 motors every time I edit or replace a motor mount in a subassembly.

Being able to change selected fields in all selected simulations to a common value would be one way to accomplish this, but in fortunately this isn’t possible.
 

Mike Haberer

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Here’s a general RockSim10 question.

Is there a way to override the calculated component weight on general components that originated as databaseloaded parts like nosecones, airframes, couplers and motor mounts?

I have several kits where the actual component weights don’t match the RockSim component weights.

One of the first things I do for every kit I build is to update the RockSim design with the actual component weights to see how it affects the design’s simulation motor set for the prospective motors.

For example, my modified Apogee Peregrine has significant weight differences with every component.

The individual “calculated” component weight for each component isn’t updated when you modify the component override weight, CG, and check the box.

Its irritating that the only way to determine if the override is working correctly is to use a calculator on the before and after overall rocket weight. This gets old really fast when you’re modifying all of the weights in the RockSim design of a kit or want to determine where the weight discrepancy is.
I use the component weights to get a sense of where the CG is during the build. As long as it's at least 1 caliber above the CP (which I assume Rocksim is calculating properly) I go with it. Once I'm completely done with the rocket, including all paint and recovery gear loaded (but NOT the engine), I find the CG by finding the balance point and weight the rocket to get the final weight. Then I do CG and weight overrides at the Rocket level. From there, Rocksim will calculate the adjusted CG based on the motor you load and the estimates for flight characteristics will depend on setting the parameters for the day of flight (elevation, wind speed, etc.) and let Rocksim calculate the rest.
 

QFactor

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Here’s a general RockSim10 question.

Is there a way to override the calculated component weight on general components that originated as databaseloaded parts like nosecones, airframes, couplers and motor mounts?

I have several kits where the actual component weights don’t match the RockSim component weights.

One of the first things I do for every kit I build is to update the RockSim design with the actual component weights to see how it affects the design’s simulation motor set for the prospective motors.

For example, my modified Apogee Peregrine has significant weight differences with every component.

The individual “calculated” component weight for each component isn’t updated when you modify the component override weight, CG, and check the box.

Its irritating that the only way to determine if the override is working correctly is to use a calculator on the before and after overall rocket weight. This gets old really fast when you’re modifying all of the weights in the RockSim design of a kit or want to determine where the weight discrepancy is.
After overriding the Mass and CG, are you saving the info to the data base? You can build a custom data base.

You can also go into RockSim's material list and make changes there. Select the "Rocket" tab, then select "Edit database", then select "Materials".
 
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Dan Griffing

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Once I'm completely done with the rocket, including all paint and recovery gear loaded (but NOT the engine), I find the CG by finding the balance point and weight the rocket to get the final weight. Then I do CG and weight overrides at the Rocket level.
I do this too. But its also necessary to determine how an actual kit varies from the RockSim design file that the manufacturer refers us to for determining its performance. And with proposed incremental modifications, it’s also necessary to determine how these changes would affect the performance.

Its necessary for managing decisions to know their impact before committing to them instead of simply waiting until everything is complete and then weighing the result.
After overriding the Mass and CG, are you saving the info to the data base? You can build a custom data base.
This wouldn’t be feasible. Each airframe section has its own custom weight so the database management would be a nightmare.
 

QFactor

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I do this too. But its also necessary to determine how an actual kit varies from the RockSim design file that the manufacturer refers us to for determining its performance. And with proposed incremental modifications, it’s also necessary to determine how these changes would affect the performance.

Its necessary for managing decisions to know their impact before committing to them instead of simply waiting until everything is complete and then weighing the result.

This wouldn’t be feasible. Each airframe section has its own custom weight so the database management would be a nightmare.
So are you wanting RockSim to do bulk analyses on bulk designs on sim files from the manufacturers?

Is this your personal project or part of a group project?
 

Dan Griffing

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So are you wanting RockSim to do bulk analyses on bulk designs on sim files from the manufacturers?
Nope.
Is this your personal project or part of a group project?
It’s just my personal project.

I have six design files for a configurable rocket (a 54mm MMT modified Apogee Peregrine) in single and dual deployment modes with two optional 18” airframe extensions because I’m using 38 and 54mm hybrids as a motor option, but the number of possible motors is about 50, including both 38 and 54mm.

So when I make a potential design change, such as wrapping the airframe sections with carbon fiber and laminating the fins, I want to do test simulations of all six design configurations with all 50 motors.

I’m a retired engineer who was used to doing similar multi-configuration designs and evaluations.

I have two other rockets that I’m also doing this kind of development for.

One of the goals is to select a reasonable subset of motors to budget for and order, and to plan for a reasonable set of actual launch configurations over the next few launches during next season.

Ultimately its to combine this with a range of launch experience to figure out what I want to do for an L3 project.
 

QFactor

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Nope.


It’s just my personal project.

I have six design files for a configurable rocket (a 54mm MMT modified Apogee Peregrine) in single and dual deployment modes with two optional 18” airframe extensions because I’m using 38 and 54mm hybrids as a motor option, but the number of possible motors is about 50, including both 38 and 54mm.

So when I make a potential design change, such as wrapping the airframe sections with carbon fiber and laminating the fins, I want to do test simulations of all six design configurations with all 50 motors.

I’m a retired engineer who was used to doing similar multi-configuration designs and evaluations.

I have two other rockets that I’m also doing this kind of development for.

One of the goals is to select a reasonable subset of motors to budget for and order, and to plan for a reasonable set of actual launch configurations over the next few launches during next season.

Ultimately its to combine this with a range of launch experience to figure out what I want to do for an L3 project.
Thanks for explaining your goal. I think you would have to reach out to Tim Van Milligan at this point to see if you can run combinations on the scale you're describing. You may be able to cut down the workload by creating a custom motor file, creating subassembly files, etc. Based on my experience with RockSim (personal designs and kit modifications), I think it's geared for single design runs, and a user that's focused on modifications for that one design. I don't see RockSim as being setup to run like an Excel Spreadsheet, but Tim is the person to make that determination.

Best of luck. Hope you find the answers.
 

Dan Griffing

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Thanks for explaining your goal. I think you would have to reach out to Tim Van Milligan at this point to see if you can run combinations on the scale you're describing. You may be able to cut down the workload by creating a custom motor file, creating subassembly files, etc. Based on my experience with RockSim (personal designs and kit modifications), I think it's geared for single design runs, and a user that's focused on modifications for that one design. I don't see RockSim as being setup to run like an Excel Spreadsheet, but Tim is the person to make that determination.

Best of luck. Hope you find the answers.
RockSim version 10 is based on an old code base, and with a single developer.

A significant part of my career was with similar large mature software projects. Significant modifications that aren’t already implicit in the architecture are all but impossible, regardless of the skill of the programmer.

I’ve had interactions with TVM before and he’s also likely to be monitoring TRF threads about RockSim10, at least I would in his place.

From my understanding of the near impossibility of making architectural changes to large mature software projects with limited resources, I wouldn’t even ask Tim to have his programmer attempt to do such a thing.

Its enough to ask for small changes while assuring that no software features get broken and everything gets sufficiently tested.

Adding a new aspect to the simulation like “gravity turn“, or a turn from wind-cocking on the fins would be much easier to implemented.
 
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