Estes Sizzler (2127) Upscale?

[Screaminhelo]

And idea started rattling around in my head the other night.

I have always thought that the rear eject Estes Sizzle was a sharp looking rocket. I looked at the OR file by K'test and looked over a copy of the plans, figuring that I would do a clone. That's when strange things began to happen. For some unexplained reason, the scale window opened and, before I could stop it, the plans had been scaled to 2.6". It seems as though it would do O.K. at this size but I am not entirely sure if a rear eject would be a good idea. My gut feeling is that it would do just fine. Has anyone out there flown something this size using rear eject? If so, would it be a good idea to have the engine pod and airframe on separate chutes?

 

[jhill9693]

I plan to do one soon with 2" mailing tube. Rear eject should work just fine on mid-power rockets. Just don't skimp on the retaining hardware (a small u-bolt would be ideal as opposed to a screw eye) and use at least 800# kevlar line. The forward end of the shock cord is going to take a beating. You may be able to preserve its life by filling the engine tube with wadding.

 

[Back_at_it]

I like look for the #2127 but the rear ejection was irritating to say the least. While it worked mostly, I never really cared for it. I too have been messing around with the idea of upscaling it. My plan was to do a 2in. version using Estes Pro parts.

 

[jhill9693]

I like look for the #2127 but the rear ejection was irritating to say the least. While it worked mostly, I never really cared for it. I too have been messing around with the idea of upscaling it. My plan was to do a 2in. version using Estes Pro parts.

Great idea! Maybe I’ll do it that way instead of with mailing tube… probably easier to get an approximately correct nose cone for it.

IMO, the original design had two main flaws: one was that it was too heavy and space constrained. A BT-55 was nested inside a BT-60 purely to allow for TTW fins, but that is totally unnecessary given that this thing will land pointy side down, not fin side down like most rockets. It adds weight, it constrains the space for the parachute, and worst of all it is underpowered on most 18mm engines. I recommend going up a size on the motor and skipping the TTW fins and stuffer tube.

On upscales, epoxy fillets and a heavy wall tube will be important. Maybe also use a coupler as a stuffer tube and take the fins through the wall to the coupler.

 

[Back_at_it]

The SIM I put together uses 2.0in tubes, a 29mm motor mount, TTW fins and nose cone ejection. I'm not including the rear ejection.