Open rocket

[Scott Nokes]

Good morning all

Does anyone know if open rocket tells me the thrust to weight ratio? I'm a new user of the software
Thank you

 

[neil_w]

I don't think so, unless it's hidden somewhere. However, T/W is merely a rule of thumb; OR will tell you the speed off the launch rod (or rail), which is what you really care about.

Thrustcurve.org will do this as well. For speed off the rod, aerodynamics of the rocket aren't very important, basically just dependent on mass.

 

[OzHybrid]

I don't think so, unless it's hidden somewhere. However, T/W is merely a rule of thumb; OR will tell you the speed off the launch rod (or rail), which is what you really care about.

Thrustcurve.org will do this as well. For speed off the rod, aerodynamics of the rocket aren't very important, basically just dependent on mass.

When's the new release coming? Can we export the nosecone as an STL. ? Or at least a series of points?

 

[Scott Nokes]

I don't think so, unless it's hidden somewhere. However, T/W is merely a rule of thumb; OR will tell you the speed off the launch rod (or rail), which is what you really care about.

Thrustcurve.org will do this as well. For speed off the rod, aerodynamics of the rocket aren't very important, basically just dependent on mass.

Ok thank you neil

 

[Scott Nokes]

When's the new release coming? Can we export the nosecone as an STL. ? Or at least a series of points?

Hey there Norm
I haven't seen anything about new release, mine is a few years old. Does it update itself or does it have to be reinstalled when upgrading.

 

[OzHybrid]

Hey there Norm
I haven't seen anything about new release, mine is a few years old. Does it update itself or does it have to be reinstalled when upgrading.

Neil @neil_w is part of the development team on GitHub.
When it's released, the best way to install it is as an AppImage with all the dependencies. This avoids any stupidity caused by your OS thinking the dependency new update is better......and then breaking it. As OR is maintained by unpaid volunteers, it's not possible for them to keep up with the vagaries of the nuanced dependency "upgrades" that Wondoze and Apple(that's a year old and I don't support it any more) impose.
Norm

 

[neil_w]

When's the new release coming? Can we export the nosecone as an STL. ? Or at least a series of points?

That is not in there. It's certainly a good candidate for the next release after this one.

New release should be out... well making those predictions has proven to be a bad idea. But it's getting seriously close to public beta.

 

[rocketgeek101]

While not the most convenient, OR does report the thrust to weight ratio when you print/export the design to pdf.

 

[lakeroadster]

Select "File", then select "Print/Export PDF..."

 

[Cape Byron]

Select "File", then select "Print/Export PDF..."

View attachment 503562

Learn something new every day...

So, what is a 'good', 'ideal' or 'minimum' thrust to weight ratio?

 

[lakeroadster]

Learn something new every day...

So, what is a 'good', 'ideal' or 'minimum' thrust to weight ratio?

That's kind of like asking "What's The Best Glue?" because the answer is" "It depends": on the rocket & what kind of launch visual you're after.

I ended up buying F52-5C motors for my TWA Moonliner, just to keep the thrust to weight ratio above 5:1, well, and also because the F52-5C has a translucent exhaust plume studded with supersonic shock diamonds and no smoke, which appears to make your rocket leap off the launch pad. Perfect for a 1955 era Moonliner.

More here: Thrust to Weight Ratio

 

[Voyager1]

Learn something new every day...

So, what is a 'good', 'ideal' or 'minimum' thrust to weight ratio?

The 'minimum' depends on your rocket's drag, launch rod/rail length, wind and the desired vertical velocity off the launcher. Ideally, you want the velocity off the rod to be at least 15-20 m/s. If there's not wind you could get away with T/W > 3:1; typically you want at least 5:1. The 'maximum' T/W for your rocket depends on how well it's built and the materials used.