I am developing a rocket that will fly with the L1256 with a body diameter of 3.4 inches and a length of 58 inches. This rocket will have 2 rail buttons. The diameter of these buttons is 0.575 inches and the length is 0.6 inches. I am afraid that these dimensions of the slide legs will tilt the rocket during and after takeoff. Will this happen. How can I prevent it if it happens.
Effect of rail buttons on the pitch angle of the rocket
- Thread starter utkan.kya
- Start date
Help Support The Rocketry Forum:
- Joined
- Feb 26, 2012
- Messages
- 2,197
- Reaction score
- 985
Stick two buttons 180 degrees to the one set. This is how the big boys ( wallops ) Flys alot of sounding rockets
I didn't fully understand what you said, but should I use 4 rail buttons in total, two opposite each other and behind the center of gravity, the other two opposite and behind the center of gravity.
The other 2 exactly opposite of the first 2.
-Slick-Ice
Well-Known Member
I haven't made a rocket that didn't spin so I haven't noticed any difference. One of mine has 3 sets of fins so the 1010 and 1515 rails can't be placed 180 apart.
I'm not afraid of the rocket spinning around. That's okay. But I'm afraid of unstable flight. For example, the spiraling of the rocket during flight, or a sudden banking when exiting the ramp scares me.
Most rockets have rail buttons and fly perfectly straight.
While your rail buttons are quite a bit larger than the normal 1010 rail buttons, the drag they create will be very small compared to the corrective force of the fins, if properly sized.
While your rail buttons are quite a bit larger than the normal 1010 rail buttons, the drag they create will be very small compared to the corrective force of the fins, if properly sized.
Most rockets are not built precise enough to be able to see a difference of flight from the rail buttons. Any spin (which is very common) basically can negate any minor off-sided drag.
To put things in perspective, just how precise are you building your rocket? What is your experience with rockets of this type? Have you done any video of your rockets in flight to see whether they spin?
Ironically, often the external camera itself would be more drag than the rail buttons.
To put things in perspective, just how precise are you building your rocket? What is your experience with rockets of this type? Have you done any video of your rockets in flight to see whether they spin?
Ironically, often the external camera itself would be more drag than the rail buttons.
Also you can try fly away guides, aerodynamic buttons, or tower launchers (the launchers that have slots for the fins and don't require buttons).
Last edited:
Last year I flew 6000ft with the CTI L1050, which was smoother than I expected and made a small turn of about 10 degrees in total until apogee. However, in this rocket I am using Aerotech L1256 and I am targeting an altitude of 11500ft. Therefore, my body diameter is smaller and my rail buttons are much larger.Most rockets are not built precise enough to be able to see a difference of flight from the rail buttons. Any spin (which is very common) basically can negate any minor off-sided drag.
To put things in perspective, just how precise are you building your rocket? What is your experience with rockets of this type? Have you done any video of your rockets in flight to see whether they spin?
Ironically, often the external camera itself would be more drag than the rail buttons.
As noted above, if concerned about the drag of the buttons, you can try fly away guides (they drop off after leaving the rail, but you need to remember to get them back) or find a club or person with a tower launcher.
This is also great reading and another option may be rail guides or a chamfered lug used with a big rod:
https://www.apogeerockets.com/downloads/PDFs/launch-lug-drag.pdf
Also thinking outside the box, if you're worried about tilting of the rocket due to off-side drag from the buttons... put an identical set on the other side.
I doubt the 10 degree turn was due to rail buttons?
Similar threads
