Before you purchase anything, you need to understand several things about hobby rocketry motors.
1.) Commercial hobby rocket motors are standardized to certain motor casing diameters and certain grain lengths.
2.) For CTI, the casing diameters are: 24 mm, 29 mm, 38 mm, 54 mm, 75 mm, 98 mm and 150 mm.
3.) For each casing diameter there is a nominal grain length: 1G in 24 mm is 1.25" long; 1G in 29 mm is 1.75" long; 1G in 38 mm is 2.30" long; 1G in 54 mm is 3.31" long; 1G in 75 mm is 5.33" long; 1G in 98 mm is 6.06" long; and 1G in 150 mm is 8.04" long. The uniform grain length make it convenient and economical to assemble motors.
4.) For each casing diameter there are nominally 7 casing lengths: 1 G, 2G, 3G, 4G, 5G, 6G and 6GXL. We'll ignore the 6XL motors for now since the grain lengths used can be different than the nominal grain length for the casing diameter.
1G in 38 mm is nominally ~120+/- Ns, 1G in 54 mm is nominally ~ 400+/- Ns.
5.) You can not only purchase the longest motor casing for a given casing diameter. This is not allowed by the certification authorities for safety and performance reasons, so you have to buy several casing lengths in a given diameter if you want to use all the reloads in a given diameter. To reduce the cost to the user, there are 1G spacers that allow you to use a longer casing than the reload would normally require. For example, if you use a 3G reload you would normally use a 3G casing, however you can use a 4G casing with a 1G spacer, or a 5G casing with (2) 1G spacers. You are only allowed to use a maximum of (2) 1G spacers in a larger casing so for example you can not use a 6G casing with (3) 1G spacers because using (3) 1G spacer is not allowed by the certification authorities.
6.) The CTI has starter casing sets that consist of (1) 3G casing, (1) 6G casing, (2) 1G spacers, 1 delay adjustment tool, and in certain diameters forward and/or aft closures. This allows you to use 1G thru 6G reloads with only (2) motor casing lengths.
7.) 38 mm starter casing sets cost $110 and 54 mm starter casting sets cost $220 from AMW Pro-X.
8.) Smaller diameter casings are less expensive than larger diameter casings.
9.) 38 mm reloads are less expensive than 54 mm reloads because they have a lower total impulse and contain less propellant. For example, a 1G 38 mm Blue Streak propellant cost $8 whereas a 1G 54 mm Blue Streak propellant cost $20. The other components of the 38 mm reload costs ~$16 whereas the other components of the 54 mm reload cost ~$31.
The 2.6" FG Mad Cow V2 is a fine rocket but it is not one I would recommend as your first high power kit for several reasons. It uses more expensive 54mm motors instead of less expensive 38 mm motors, and it is quite sensitive to CG location and will require nose weight for a stable flight so it's really not a good first high power rocket, and it is not set up for electronic deployment which will make recovery easier when you go high on a L2 motor.
A better choice for your first high power rocket in a Mad Cow 2.6" FG kit would be a dual deploy ready DX3, Screech, or Tomach with a 38 mm motor mount. (They are basically the same rocket with slightly different fins.) They can be flown with, or without, dual deploy, with, or without, electronics, and with, or without, the payload section. They are much more versatile than the 54 mm V2, and much less expensive to launch, and more important to a newbie, you are less likely to loose it.
1.) You can do your L1 without electronics in an apogee deploy motor ejection mode. A simple up and down flight on a 3 grain Pro38 mm H motor.
2.) You can purchase a PerfectFlite StratoLogger and build your e-bay and install the altimeter and simply monitor your next few flights on 3G or 4G H motors.
3.) When you are comfortable with the electronics, set up the rocket for dual deployment and do that with a 4G or 5G I motor.
4.) After you are comfortable with dual deployment , go for your L2 cert using the dual deploy with a 5G or 6G reload.
You can always buy the V2 first, but this is an easier approach to get to L2 using one rocket.
YMMV
Bob
