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Old 04-11-2008, 12:18 PM
shockwaveriderz shockwaveriderz is offline
rocket dinosaur
 
Join Date: Mar 2005
Location: My Old Kentucky Home
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Mark:

I can help somewhat here with Coaster motor data.

Coaster had at least 3 F size modelrocket motors: the F11 (F50) and the F15(F67) and the F25(f111); these are English/Metric values.

The total impulse for the F50 was 50Ns while the F15 was 63Ns. Max Thrust was 89N for the F11 and 156N for the F15. The thrust durations were F11- 0.45 sec and 0.7 sec for the F15 . The Isp (Specifric Impulse) for the F11 was 54 sec while for the F15, 68 sec. The propellant mass for both was in the 2.9 oz range. (thats about 83 grams !!!!!) . Yes these were way over the 62.5g limit, but at that time there was NO 62.5 g limit... the NAR did not allow its memberse to cluster these as the propellant weight was in excess of 113g, the FAA limits. I'm sure some people did. Both of these motors featured what I call dual-core geometries; they looked like the B14 internally. hmmmmm.

For those that know anything about BP rocket motors, the ISp looks way low compared to estes 70-80 sec for an ISp. Why was this? Simple, these were originally pyrotechnic Bp skyrockets and used a slow 60/30/10 BP mix as opposed to the Estes standard 75/15/10 (fast) mix. Thats also why they had so much BP propellant in them.


Both of these wre 8" x 1.062 " Od with an ID of 0.875. They had a whopping 0.5" diameter Nozzle Core and the nozzle was inset from the end of the convolute wound paper casing by 0.375" to provide a more increased nozzle expansion ratio.

They had that gummed outer labeling paper wrapper that you removed off the tops and bottoms before flight.

Centuri started selling the F11 in their 1964 catalog. By 1965, Centuri had absorbed Coaster and was offering the F11 and F15 as Atlas and Hercules , where the Atlas were E size motors (these I beleive were Centuri designed BP motors) along with a new F25 (F111) !!!!!! which was also a Coaster original. This monster had a whopping 69 Ns of Total Impulse!

Obviously this F25 was way before the 80Ns max average thrust limit that we have today for model rocket motors.

See the 64-65 Centuri Catalogs at Ninfingers for more info.

Ninfinger doesn't have a 1966 Centuri catalog, so if anybody has one, please scan and post there ? Or just scan the Atlas/hercules pages and post? or email to me please?


I don't really know how many of the Centuri Atlas E's actually made it to market(if at all) or the Hercules F25.

Sometime in the 66-67 timeframe, the Centuri renamed the Atlas/Hercules to "Mini-Max" and they had D,E, F BP motors. the old Coaster F11/F15 had now become the F10/F14. Again, I don't know how much of the D,E size Mini_Max were actually sold or made it to market.

Remember, that between the time Centuri absorbed Coaster in mid 1965 to 1969, during that period, Centuri was constantly improving and tweaking the original BP Coasters.

There's also NO 1970 Centuri catalog at Ninfingers, so I can only guess that somewhere in the 69-71 timeframe, Centuri quit manufacturing the older BP Min-Max and started manufacturing the newer composite Enerjets.

Again if you have a 1970 Centuri catalog, please consider scanning it and posting at either Ninfingers or YOR and or send me copy of just the motor pages.

I won't go into to much detail on the FSI motors suffice to say the F100 was actually an E60 and the F7 was actually an E5.

As far as Prodyne was concerned they offered D2.5/D3.5 ( D11/D16), E2.5/E3.5( E11/E16) and F2.5/F3.5 (F11/F16) BP motors that used a hi-temp plastic casing and these ranged in size from 4-7.125" in length with an OD of 1.0"and an ID of 0.810 for the Cyclones and 3-6.0" x 1.125" OD x 1.0" ID . The F11's had an Total Impulse of 45.4Ns while the F16 was 53 Ns, so they were barely an F. These were low thrust long burn (4.0 sec burn time for the F11/F160, had a propellant mass of approx. 2.3 oz, with an Isp of 80-85 sec.
The Cyclones had a a nozzle core of .01875, recessed .01875 into the casing., while the Hurricanes, had a nozzle diameter of .234" . These were ALL semi-core end burners like Estes end burners. I might add that the Cyclone core dimension are the exact same core dimension of the old B14 motor. hmmmmm....

The Cyclones had a peak thrust of 4.25 lbs(19N) and a sustainer thrust of 2 lb(9N).


The Hurricane's were the D,E,F 3.5 while the Cyclone's were the D,E,F 2.5


hth

terry dean
nar 16158
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