How to find the right delay?

[BsSmith]

I'm making a motor list for Midwest Power this year. I know what delays to use in most of the rocket's I'm launching, but two of them are using motors that I've never used before. Is there any basic rule of thumb to time the delays for rockets?

One of the ones I'm launching is my Mystic Buzz on an H250G, there is no H250 file in Rocksim so I can't run simulations to find a *close* to right delay. The rocket is just under 2lbs unloaded and uses a medium delay on an H128. In Rocksim, a medium delay on an H220 will deploy the parachute just after apogee.

The other one is my Pem Tech King Kraken on an H112J, the Kraken has flown twice on H73s and a short delay deploys the parachute at apogee. The H112 has a bit more power to it so I think it would need a longer delay, but that's only a guess.

Also, does anybody have a Rocksim file for an H250? I need to see how fast the Mystic Buzz will go on it so I don't rip out the fins.

 

[brianc]

Also, does anybody have a Rocksim file for an H250?

https://www.thrustcurve.org/download.jsp?id=675

And here's the H112J-
https://www.thrustcurve.org/download.jsp?id=916

 

[Sailorbill]

Check out this thread on Rocketry Planet.