Launch Guide Selection
Greetings all. Sorry for such a basic question. But, I am building two 2" OD rockets. They will run on D-12 engines. What would be the appropriate guide tube size?
For launch rods, I'd suggest 3/16in or, better, 1/4in. If you plan on launching this rocket with higher impulse motors, consider rail buttons. Standard buttons for 1010 rail or 20mm rail buttons can be accommodated at CENJARS.
If you go with rod launch lugs, be sure to have them oriented straight. A piece of rod through your lugs when you glue them on can insure that. I've seen rockets at our launches that do not have their launch lugs in-line with the rockets major axis or the launch lugs are canted. In either case, that causes the rocket to bind up on the rod.
That would depend on the size (length and/or diameter), weight or engine power. I don't have all that info, but based on a D12, medium size rocket, I would lean towards a 3/16" size launch lug. If you think you'd use a larger motor some day, like an E12, you could go with a 1/4", or even 1010 rail buttons, especially if it is a longer, heavier rocket. Anything using an F motor or more is probably best with rail buttons.
Also keep in mind that if you want to fly bigger motors at a larger Club launch, like MDRA or BARC, etc, they usually discourage 1/4" rods, so you'd want to use buttons.
Another option is to put a launch lug (tube) on one side, and buttons on another side.
So, if I just defaulted to the 1010 buttons, I would be covered?
Quote from randykaustin on January 29, 2026, 9:44 amSo, if I just defaulted to the 1010 buttons, I would be covered?
Yup!
There are rail guides you can glue onto your rocket or there are rail buttons usually attached with screws. If you use screws, you'll want something for them to screw into.