Apollo 27

[PSLimo]

Hey Guy's,

I'm looking to build something different and I came across the Pegasus Hobbies Apollo 27.



First question. Has anyone tried to upscale a build of one or even tried to make the plastic kit fly?

I measured the kit parts I was thinking of a 3X upscale which puts the main BT at 5.5" in diameter and the pods at 3" in diameter.

Then there's figuring out how to fabricate the fins and pods...

Phil

 

[heada]

Looks very interesting and cool

 

[PSLimo]

Here's what the dimensions look like scaled up 3X from the plastic kit:

 

[jqavins]

That looks cool. It's a quasi-goony though. I wonder if the pods are effective as fins, and if not I'd be concerned. You may need to be prepared to use a lot of nose weight and correspondingly high thrust engines. What size engines are you thinking of? What's your target weight? Am I rushing you for answers you don't have yet?

Fabrication of the fins and pods? Well, the fins could just be cut from sheets of plywood. That would have to be by laser cutter if I were doing it, but others are surely better at such things than I am.

As for the pods, I don't see anything difficult about them that's different than main body. What are you concerned about?

 

[heada]

Yes, it is kinda goony-ish.

As for the fins/pods, I think if the struts that connect the pods to the main body were solid, there would be enough fin surface combined with the drag of the pods to impact stability but I sure would like to see it sim'd. 5.5" at it's widest and tapering down to 3"?? I bet a 54mm MMT would be good. Give options from low I with an adapter up to L or M. I'm betting it'd fly just fine on a higher thrust J or decent K motor.

 

[boomtube-mk2]

My question is. What happens to that poor rear-facing astronaut during take-off?

 

[jqavins]

As for the fins/pods, I think if the struts that connect the pods to the main body were solid, there would be enough fin surface combined with the drag of the pods to impact stability but I sure would like to see it sim'd.

I certainly agree with that. If they are build as shown, as an open truss, then I'd be concerned. I can't see any reason that a pod like that, given some angle of attack, wouldn't produce at least some lift the way a flat (or airfoiled) fin does, but I'm not competent to say it does or to mind sim how much.

 

[PSLimo]

Hey Guy's,

Here's a crude sketch of what I was thinking for the fin/pod configuration. Turning some 3" balsa to shape the pods will make the details easier with the fin running through them. The total diameter would be 17.5" not the 15" stated in post 3.



The main bodytube would pretty much be two nosecones back to back with the back end cut off the rear nosecone to a 3" diameter with a centering ring to a 54 mm motor tube. I'm thinking nose weight will be along the lines of the 8" diameter FatMan I built where half the total weight of the rocket is in the nose.

Phil

 

[lakeroadster]

Neat project. Lots of base drag and a stubby rocket.

How about making those rear pods swivel 180 degrees, and have it launch VTOL style as a tractor motor design, how cool would that be?

@Daddyisabar approved!

 

[lakeroadster]

Here's a really quick Open Rocket simulation.. just as a what if... I had to use the base drag hack to get it stable enough to simulate. But a swing test should tell you stability before flight.

I used the OR-19 version. I tried the OR-22.02 version but it wouldn't load motors.