Hi first time posting, but a long time lurker. I'm building a pvc saber using the soundboard from a vader ultimate fx saber. I figure this would be a good practice run. I have my electronics working fine. My question is how much of the blade needs to sit inside the emitter/ blade holder? I want to make sure that my blade won't come out even with the blade screw. Plus it will help with the placement of the LED.

Thanks for your time.