4" low power airframes

[Zeta]

Hey anyone out there using 4" dia. low power (cardboard/kraft) airframes ...and how do you like them, and what material are you using for rings ? I want to go big but light with E / F
motors.

 

[SeanW78]

The maiden flight of my Madcow Super DX-3 was on an Aerotech G80. That's a light motor for it, but it's also a sizeable rocket. The rings and fins are 1/4" plywood and fully built it came in just under 4 pounds set up for dual deploy. You could definitely go smaller, but I'd probably stick with 1/4" ply for rings. Plenty of strength and not too heavy.

 

[Sandy H.]

I bought some BT-101 years ago, basically 3.9" tube that is just like a BT-80 in construction, but bigger. Very light and easy to crease, but probably fine. I *think* NCR used this type of tube for large 3FNC rockets that could fly on small motors.

I also got a similar lightweight nosecone and planned to build a 3-4ft tall 4" diameter rocket that would fly fine on E's for Scout/Demo launches. I got busy and never did. Might be worth resurrecting, though.

Sandy.

 

[teepot]

It might be hard to come up with a light rocket for those motors. A 4" LOC tube 34" long weighs 9.9oz.

 

[mrwalsh85]

Some of the North Coast Rocketry kits were 4" diameter.

Check out LOC Precision. I'm sure you'll find a few 4" kits that can fly on a G motor, maybe even an F. The Loc IV comes to mind....

 

[hakudoh]

I challernged big Rocket with B moter.
I used styrene paper for body and rings.

http://gallery-h.net/top/?p=494

 

[scschulte]

Hey anyone out there using 4" dia. low power (cardboard/kraft) airframes ...and how do you like them, and what material are you using for rings ? I want to go big but light with E / F
motors.

I just love my kraft airframe MadCow 4" diameter Frenzy: https://www.madcowrocketry.com/4-frenzy/ but you'd have to likely use at least an "H" motor -- This is a great kit -- I've flown it 7 times and it is solid - the fins especially! Check-out my Sept 2021 launch with the Frenzy followed by my Endeavour! Steve Wednesday 10 November 2021

 

[DeeRoc29]

I believe the op is asking about Estes BT-101 .021" wall tubing, not LOC or Madcow HPR tubing. Zeta, check out Balsa Machining Service. They sell fiber centering rings for BT-101. Erockets carries the tubing. You could definitely build a rocket light enough for E/F motors. The original Estes 1/100 Saturn V was based on BT-101 tubing and flew on a D12.

 

[Zeta]

I believe the op is asking about Estes BT-101 .021" wall tubing, not LOC or Madcow HPR tubing. Zeta, check out Balsa Machining Service. They sell fiber centering rings for BT-101. Erockets carries the tubing. You could definitely build a rocket light enough for E/F motors. The original Estes 1/100 Saturn V was based on BT-101 tubing and flew on a D12.

Thanks DeeRoc!

 

[teepot]

A BT 101. Learn something new every day.

 

[Pete.D]

I built and flew the Estes Saturn V (kit #2001) years ago, on a D12-3. As I recall it only went up about two hundred feet, but recovered OK on the 3 stock Estes plastic parachutes (two for the booster, one for the 3rd stage and above). I've still got it and the box it came in, but haven't flown it since back then (it was in the 80s). I just weighed it; it totals 10.8 oz with the escape tower (but without the display nozzle assembly), but is not fully detailed or painted beyond the wrappers, cable tunnels and a couple coats of sanded white primer. It has the original slightly-oversize balsa fins, and did not require ballast. I imagine that performance in fully detailed and painted condition would be poor on a D12, but great on a composite E20 and awesome on any F.

Of course the Saturn V is a pretty heavy and draggy rocket with all the fins, shrouds, transitions, plastic capsule and escape tower assembly. A simpler BT-101 airframe would fly great on a D12.

 

[rharshberger]

I believe the op is asking about Estes BT-101 .021" wall tubing, not LOC or Madcow HPR tubing. Zeta, check out Balsa Machining Service. They sell fiber centering rings for BT-101. Erockets carries the tubing. You could definitely build a rocket light enough for E/F motors. The original Estes 1/100 Saturn V was based on BT-101 tubing and flew on a D12.

+1, LPR ends at D motors according to most peoples understanding, MPR is E, F, and G motors (there are a few G motors considered HPR), H and above are HPR. A BT101 rocket powered by a D motor is possible but needs to be kept under 14oz if its an Estes D12-3.

 

[Zeta]

I built and flew the Estes Saturn V (kit #2001) years ago, on a D12-3. As I recall it only went up about two hundred feet, but recovered OK on the 3 stock Estes plastic parachutes (two for the booster, one for the 3rd stage and above). I've still got it and the box it came in, but haven't flown it since back then (it was in the 80s). I just weighed it; it totals 10.8 oz with the escape tower (but without the display nozzle assembly), but is not fully detailed or painted beyond the wrappers, cable tunnels and a couple coats of sanded white primer. It has the original slightly-oversize balsa fins, and did not require ballast. I imagine that performance in fully detailed and painted condition would be poor on a D12, but great on a composite E20 and awesome on any F.

Of course the Saturn V is a pretty heavy and draggy rocket with all the fins, shrouds, transitions, plastic capsule and escape tower assembly. A simpler BT-101 airframe would fly great on a D12.

Pete, Thanks I will shoot for 10 or less ounces. !

 

[TheTank]

T-Loc 4, Loc 4” Goblin… I have flown them both on F67s for low and slow flights… but prefer at least Gs when not flying HP.