FSI booster meets Estes upper stage

[ronhill]

This design started when I wanted to find something to do with an old FSI E5-0 engine—date stamped 1975. Remember that it has a 6 second thrust time.

Obviously the upper stage has to be very light. I suppose I’ll put an A or B engine in that upper stage. Even then I doubt I’ll ever see it again although it's equipped with a mylar streamer. If, by chance, it comes back home, I have a D18-0 to try in it.

The upper stage fins (plywood) came from an FSI Stargazer kit. That body tube was crushed in a move 25 years ago.

The lower stage body tube is one of those yellow spacer tubes that comes in Estes kits. It seems to fit the FSI engines well. The fins are from a Stormcaster kit. The stage coupler is a peeled D12 engine casing. The rear of the upper stage engine slides tightly into this coupler and rests right on top of the lower stage engine.

I'll provide a flight report after tomorrow.

 

[rabidsheeep]

sweet! stick the d18 in the upper. get that back and you know you had a good day

 

[Nuke Rocketeer]

I still have a bunch of D20-0's, D18-0's D20-6's, D18-6's and E5-6's that I use. They have flown well and I got the upper stage back every time, The last time I launched a couple of weeks ago, the E5 in the upper stage blew forward just a second after the booster ignited it, ruining the upper stage.

Joe W

:kill:

 

[ronhill]

Well, it was a 50% day. The first flight was with the E5-0 in the booster and an A8-5 in the upper stage. I worked perfectly. The E5 always gives a good show. It was a very high boost. I used the A engine simply to keep it in sight.

With that success, I put a D18-0 in the booster and another A8-5 in the upper stage. The D18 did great, but the upper stage failed to ignite, and it lawndarted with the booster still attached. There was propellant material thrown up into the upper stage nozzle, but it didn't light. It's my fault. The only A8-5 I had was a 1974 vintage engine. I'd flown a number of them (as single stages) with no problem, but they have a small nozzle throat, and I'm sure the age affected their willingness to ignite.

Overall, even with a 50% score, it a fun experiment. The combined ages of the engines for each flight was 61 years!

Joe W: I was beginning to think I was the only person still with a cache of FSI engines The two flights today were the last of the batch of 30 or so with a full range of engines. I had only one failure in the bunch--a D18-6 CATOed last year. But as I remember, they had a tendency to do that in 1975. That's the reason FSI came out with the D20s.

 

[brianc]

Originally posted by ronhill
...it lawndarted with the booster still attached.

Damage? Repairable? You know the drill- PICTURES!!!!

 

[ronhill]

Originally posted by brianc
Damage? Repairable? You know the drill- PICTURES!!!!

The booster is pristine--no damage at all. The upper stage was pulverized back to the fins. In my haste, I chucked the trash of that upper stage so there are no pictures. I'll remember to get shots in the future of any damage (it's a good bet there will be others!)

I'm going to try to salvage the fins of this upper stage (BT-20 based) and use it with the lower stage for plain old 18 mm engines now that my Flight Systems engine supply is gone.

Ron

 

[Nuke Rocketeer]

Originally posted by ronhill

Joe W: I was beginning to think I was the only person still with a cache of FSI engines The two flights today were the last of the batch of 30 or so with a full range of engines. I had only one failure in the bunch--a D18-6 CATOed last year. But as I remember, they had a tendency to do that in 1975. That's the reason FSI came out with the D20s.

The only reason I still have my cache of FSI engines is because I got out of the hobby for about 8 years in 1992. I also still have a bunch of E60's, but only burn those in a 29mm rocket on its last legs, 'cuz those tend to cato in 1 out of three times.


Joe W