Sonic 2200 Staging Question

I am building a USR Sonic 2200. For those who don't know (and I bet that's most), this is a two stage design 2.2" in diameter from the days of yore. Anyhow, the booster unit is basically stand-alone and mounts via a coupler into the bottom of the sustainer. The booster uses motor ejection.

Sustainer is to have an Adept two event timer mounted mid-ship for motor ignition. Ejection can be fired either by this timer or a small Transolve altimeter that is to be mounted in the same bay

First flight currently planned to be AeroTech F62T (w/4 sec delay) in the booster staged to an AeroTech F23FJ-7.

Here's my question - should I use a small BP charge to seperate the booster and sustainer before motor ignition? The timer has a channel for it (assuming I use the altimeter for the parachute). I was thinking that the F62 burns about 1 sec, and that I could separate the booster and sustainer at 1.5 sec followed with sustainer ignition at 2 seconds. This would keep the booster from getting flamed by the sustainer.

Thoughts? Should I separate prior to sustainer ignition?

I have a Sonic 3300 Phase II. Fiberglassed, but not built yet. I planned on a loose fit coupler and drag separation versus a charge with an adequate delay before lighting the sustainer.

I have an old school Sonic 2200 I used to fly on mercury switch staging / capacitor discharge... flies great F60 to D12 or E15.

Need to dig it out and convert to electronics, started that years back then lost interest

Never had much issue with major damage on the booster with staging on the booster - just blows the booster off, if not too tight, some sot damage, but nothing major, with BP motors, composite upper stages might burn it more .

Coat the inside of coupler with finishing epoxy, make sure the coupler is a nice loose slip fit - also put a heat shield or wadding ( we used now taboo fiberglass insulation back then ) , ABOVE the chutes..never burnt a booster chute on mine, with no bulkhead above the chute, just glass wad on top of the chute.

post pics, always neat to see these old timers - memories of LDRS 1,2


~ AL

TRA 090

green dragon said:

I have an old school Sonic 2200 I used to fly on mercury switch staging / capacitor discharge... flies great F60 to D12 or E15.

Need to dig it out and convert to electronics, started that years back then lost interest

Never had much issue with major damage on the booster with staging on the booster - just blows the booster off, if not too tight, some sot damage, but nothing major, with BP motors, composite upper stages might burn it more .

Coat the inside of coupler with finishing epoxy, make sure the coupler is a nice loose slip fit - also put a heat shield or wadding ( we used now taboo fiberglass insulation back then ) , ABOVE the chutes..never burnt a booster chute on mine, with no bulkhead above the chute, just glass wad on top of the chute.

post pics, always neat to see these old timers - memories of LDRS 1,2


~ AL

TRA 090

Click to expand...

Al-

Thanks for the input! You are one of the very few old timers I see around here. I can remember when I first read Tripolitan back in the late 80's that you were one of the guys consistently flying at the those early launches.

My Sonic 2200 has a bulkhead in the lower coupler assembly and and I have also beefed up the inside with another, heavier piece of cardboard tuning. I am planning on a composite motor in the upper stage so I'm concerned about "flash-back" from motor ignition up into the sustainer motor mount area. That's why I dig separating the two stages before lighting the second candle.


Did you use 4 second delays motors in the booster? That seems right to me....

Jason

Jason,

Thanks for the kind words - from one old timer to another

Sounds like you have the coupler / BH situation licked.. I know mine had no BH, just open space above the mmt in the booster ( elastic shock cord tied into a hole in top centering ring and a 12" chute )

4-5 second delay sounds about right. ( thinking you might need slightly longer delay if you drag sep or use the charges, as the booster will be travelling upwards after staging, versus blowing in back when the upper lights ) .

Do remember, that with my using a mercury switch setup, that only high thrust.. preferably progressive burn, motors were used, to provide the 'burnout stop' for the mercury to fly forward to stage.
old Aerotech F60 were good, as were even older Crown F67 or ACS motors.

Bates grain motors were flat and I have had at least one flight where it did not end 'hard' enough and did not stage until coasting to horizontal attitude.
( good reason to switch to timer, or more sensitive electronic methods, like a G wiz .. hmm... I have an old G wiz, unused, might be a good thing to dig the 2200 out and try that, spring project .

keep us posted.

~ AL

ps: and pics of any old stuff always welcome , I'm a sucker for nostalgic early hpr stuff