Alright so i'm working on a rocket. its about 1 1/2 foot tall. 2in. pvc pipe. i need to find a way to keep the motor compartment seperated from the inside of the rocket. so it doesnt explode in midair. i want it to explode when it hits the ground. i'm thinking a push button igniter to stick in the tip of the rocket so the spark will set off w/e i have inside. the only problem is...seperating the motor from center of rocket. and having a strong enough motor to send this thing far enough away from me that i dont have to go to the hospital.(although that would be a sweet story). but anyway any suggenstions? i'm a noob. so help!!!!

If you are a 'noob' then don't try doing something that is relativly advanced and could be very dangerous if gotten wrong. Even as i'm saying these word i know there going in one ear and out the other so.... here are my thought's

I left a comment about the use of a lighter for a source of ignition on the other thread.

If you are making a decent rocket motor then it will be housed in a spun cardboard tube,
so you shouldn't have a problem with the motor igniting the charge, as long as it has a strong end cap. If you were planning to use the PVC pipe for the housing for the motor that wouldn't work, as it would melt the pipe and destroy the tail fins so it could go anywhere.

You say that you want to get it to explode when it hits the ground, so obviously the motor
will have finished, for the rocket to land on its nose you would have to weight the tip
quite a lot. Also if you are going to wait untill the motor runns out yyou have no real way of aiming this, as it could go 1000m of if the wind was against you could land on your head!

as said above i believe this is out of your reach unless you really know what your doing, which i assume you don't
try making smaller rockets to start with. google structural composition of fireworks and you should be able to find some basic rocket designs. once your adept at making these, move up to bigger and better things. the key to messing around with anything pyro related is to take small steps and don't try and run before you can walk

I'm hella god at making rocket designs!=P. Engineering and Drafting classes in high school actually come in handy.

If you don't know the basics of rocket construction like seperate segments and the ilk, that is WAY too big a rocket to make.

1 1/2 isnt rally that big.

a rocket body out of pvc? that's way to fucking heavy. as for the motor i would buy a pre-fab model rocket engine [Aerotech econojet]. they work, and are safe. study up on rocketry. use software to test your designs first. Winroc Model Rocket Software.
don't blow your head off unless you tape it.