Rail button question (large v. small)

[redsox15]

I am in the process of listing all the parts I need for my next rocket before I buy them all. I am turning a 6" dia. 36" tall crayon bank I have had for a while into a rocket. Anyways, I want to use rail buttons for this project and was wondering the difference between small and large rail buttons. Would I be better off using large ones because of the dia. of the rocket?

Matt

 

[cjl]

Diameter doesn't really matter. Honestly, the small ones are plenty for anything up to around 30-40lbs and a healthy L to M motor. I've flown a 37 pound rocket on an M1300 off of standard rail buttons with no issues. Above that, I'd tend to go to the large (15 series) rail buttons, or if there are large side loads expected for some reason (my deuce has the large buttons for this reason - if one motor lights late or doesn't light, there are huge side loads that occur on the rail, and I wanted the rail buttons to be nice and sturdy to prevent any problems with that).

 

[dixontj93060]

Small ones are fine. I used them on my Crayon and I built it fairly heavy.