Is there a general rule of thumb pertaining to spindle length / width and performance?
Generally I'm thinking Nozzleless, because a nozzle adds a whole other can of worms (there's SO many variables to all of this!).
I know the standard numbers for spindle sizes, but I've been playing around with them a little.
What I've settled on so far, ID x .575 gives higher thrust, and possibly a little more forgiveness (RUDwise) than ID x .5 (not to mention use less comp).
It's been working well for whistle and strobes.
But from what I read (not tested), smaller widths give higher thrust as well.
Why is the U/H spindle wider than the standard BP spindle?
Why wouldn't you just take a U/H width spindle, and make it longer for a BP rocket?
Does BP work better with a thinner spindle, because of smart brain sciencey thrust curves?
Or is it as simple as "It's not as hot as whistle, so you can push it harder before you get a CATO"?
Or even "Whistle / Strobe sounds better with a wider core, but since a BP motor is not concerned with the audible aspect, it's optimized for performance" (I don't buy that, it's just an example of some lateral explanation )