Open Rocket,CG,CP

[cjp]

When you design a rocket on Open Rocket,you see the CG,CP move as you add each part.Right now I'm looking to add some weight to my nose cone,but don't know if I'm doing this right.Does Open Rocket show you the number of calipers without the engine?My CG is 1.1 caliper(forward) from my CP without the motor,I'm looking to move it to 1.5 calipers.If I were to leave things as they are now would it be stable enough?

 

[scsager]

The stability with the rocket in a "ready to launch" configuration, is important. OpenRocket will show the stability as "Calibers" with or without the motor.

1 Caliber = 1 x diameter of the rocket. The rocket is considered stable when the CG, center of Gravity, is at least 1 cal. above the CP, Center of Pressure.

I like to have a little extra stability in my designs, so I usually shoot for about 1.5 calibers with the motor. My Super Big Bertha clone has 2.89 calibers without the motor, and 1.62 cal. with an H128, which is the biggest motor I have flown in it

 

[GDJ]

Same here.

 

[bradycros]

The stability with the rocket in a "ready to launch" configuration, is important. OpenRocket will show the stability as "Calibers" with or without the motor.

1 Caliber = 1 x diameter of the rocket. The rocket is considered stable when the CG, center of Gravity, is at least 1 cal. above the CP, Center of Pressure.

I like to have a little extra stability in my designs, so I usually shoot for about 1.5 calibers with the motor. My Super Big Bertha clone has 2.89 calibers without the motor, and 1.62 cal. with an H128, which is the biggest motor I have flown in it

How did you save the open rocket screen shots? I can't find a way to save the screen shots, let alone post the screen shots. :confused2:

 

[kruland]

Bradycros,

On windows you can use alt "prt sc" - that last bit is the "print screen" button on your keyboard. You might have to press an additional key to make it work - for example on my laptop I need to press the "fn" (function key) as well.

This takes a capture of the current application (the one with focus) and puts it in the clipboard. Then you can paste it into the windows program paint and save to a file.

There are other windows utilities out there to take screen shots. Dig around on tucows or something for an alternative if you want.

On Mac, there is certainly an easier process but since I don't use Macs I don't know what it is.

Kevin

How did you save the open rocket screen shots? I can't find a way to save the screen shots, let alone post the screen shots. :confused2:

 

[scsager]

How did you save the open rocket screen shots? I can't find a way to save the screen shots, let alone post the screen shots. :confused2:

In Win7, I use the snipping tool to do screen captures saved as .jpg and posted to TRF using the "paperclip" attachments tool on the toolbar.

Don't have Win7? Try one of the free screen capture progs.

 

[cjp]

The stability with the rocket in a "ready to launch" configuration, is important. OpenRocket will show the stability as "Calibers" with or without the motor.

1 Caliber = 1 x diameter of the rocket. The rocket is considered stable when the CG, center of Gravity, is at least 1 cal. above the CP, Center of Pressure.

I like to have a little extra stability in my designs, so I usually shoot for about 1.5 calibers with the motor. My Super Big Bertha clone has 2.89 calibers without the motor, and 1.62 cal. with an H128, which is the biggest motor I have flown in it

Thanks,That's what I was going to do, I'm going to add fender washers to get 1.5 calibers with the motor installed.

 

[bradycros]

Bradycros,

On windows you can use alt "prt sc" - that last bit is the "print screen" button on your keyboard. You might have to press an additional key to make it work - for example on my laptop I need to press the "fn" (function key) as well.

This takes a capture of the current application (the one with focus) and puts it in the clipboard. Then you can paste it into the windows program paint and save to a file.

There are other windows utilities out there to take screen shots. Dig around on tucows or something for an alternative if you want.

On Mac, there is certainly an easier process but since I don't use Macs I don't know what it is.

Kevin

In Win7, I use the snipping tool to do screen captures saved as .jpg and posted to TRF using the "paperclip" attachments tool on the toolbar.

Don't have Win7? Try one of the free screen capture progs.

Thank you for your replies.