Launch Guides Basics
Supported Launch Guides
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Launch Lugs: Low power model rockets are guided off the pad by launch lugs (short small diameter tubes attached to the body tube) which slide over a rod. The lugs guide the rocket up the rod until sufficient speed is developed for the fins to stabilize the model. These rods vary in diameter and length depending on the size and weight of the model, and the thrust of the motor. Low power launch lugs are usually just larger that 1/8" with mid power lugs are slightly larger than 1/4". |
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Rail Buttons: Rail Buttons are used in place of launch lugs when the size of the model makes it unsafe to use a rod. Launch rods tend to bend slightly from the force of the thrust until the rocket stabilizes and, with larger rockets, this can become unsafe. In place of the rod, a channel is used (commonly 1" or 1-1/2" square aluminum), and the side profile of a rail button looks like an “H” with the top and bottom of the letter sliding down into the channel. Launch buttons have the capacity to guide rockets weighing from a few pounds to a hundred pounds or more. |
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Limited Support and Unsupported Fin Sets
Launch Shoes
Warning: OpenRocket lacks native support for Launch Shoes.
Fins, generally speaking, are aerodynamic control surfaces. Where grid fins differ from other fins is that they are not essentially just flat surfaces, but more of a frame with a grid inside. Usually made of metal (such as aluminum), not only can grid fins be light, they can be very strong (the very thin, spaced grid surfaces don’t generate much drag). Although OpenRocket doesn’t support grid fins as a single component, the pod and fin set components can be used to create them.
The simulated results with grid fins have not been verified and should not be relied upon without actual flight test verification and Cd adjustments of your own.