While it's no doubt important to look at "back then", it's key to put a new twist on it moving forward.

1. Take your modular approach (booster motor with separate, glue-in delay/ejection unit) and make it like the HPR motors -> let the user dial in the delay as part of the assembly. Your basic items will be a Bx-0, a Cx-0, a 10 sec delay unit and a trimming tool. The user drills the delay and glues it into the motor (or uses it sans delay as a booster). The thrust profiles should be shaped for general use (ie, medium avg thrust - eg, B6, C6).

2. Heavy lifters: Besides the B14, how about a C20-C25? The deep core may take up much of the space (ie, length in the 2.75" case) leaving only a booster. Or, maybe the modular delay is only partially inserted ala the AVI motors. For me, I'm primarily interested in the booster.

3. How about a D impulse 18mm (x2.75") motor? With an ordinary core, it seems to me a nearly full D can be squeezed in (sans delay). Might make an interesting booster. With a deep core, I'm not sure if it would be much different than the aforementioned C20-C25.


13mm motors
4. The modular delay might get tricky. Not sure if the inside diameter of a 13mm motor case leaves enough room for lots of smoke and the thickness of the delay's wall...or maybe the delay doesn't need a very thick wall.

But the key here is to build A impulse motors only in this form factor. 13mm motors can always be adapted to 18mm and short-18mm applications, but not vice versa. Instead of spreading your resources by having A impulse 18mm motors AND A impulse 13mm motors, you concentrate them into one case that the user can then adapt up. My thinking is that the 13mm (x1.75") A motor is shipped in a package with an empty 18mm case (that is marked with a dashed line at the 1.75" mark) to be used as an adaptor. Each 3- or 4-pack of 13mm motors comes with one such adaptor. An A booster is a must. Deep core preferred.

5. 1/4A and 1/2A boosters. And if you can do the adjustable delay, that'd be awesome. A 1/4A sustainer with long delay would be very handy for my fleet, and much more universal if the user can set the delay anywhere from 0-5 seconds.

24mm motors
6. My big desire here is heavy lift - D40 and E50. Again, with the modular delays, you build one D40-0, one E50-0 and one adjustable delay from which the users can configure umpteen differents combos.

7. How about a 1.75"x24mm motor? Take Estes' C11 and saw off the unused inch.

Summary
The idea is the hit the market in the voids. Estes has a light-medium thrust E9, so you counter with the high thrust E50. Estes has a medium thrust D12, you would have a high thrust D30-D40.

Estes has 10 different 18mm B and C motors. With only three components - Bx-0, a Cx-0 & 10 sec delay module - you can cover all that and much, much more.

Estes doesn't have 1/4A, 1/2A or A boosters, but with modular delays, users will always have the booster option (by omitting the delay).

My 2 cents. Take it for what it's worth

Regards,
Doug

Doug,

This might be made easier to manufacture: Build delays of 1-, 2-, and 3-second thickness, and just let the user select which ones and how many might be needed, and stack them. Safer than drilling, and more easily "tuned" to a given flight profile.

If this is possible, even half-second intervals might be considered for competition flights...

Craig...

I was teasing Carl... well, maybe there was a little hoping there, too.

I'm not surprised about the B14 being a favorite in the polls, but I'd be really surprised if anyone would make them again considering the work involved. I'm with Phred. I nice 13mm B3 or 4 would be sweet! I loved the old Centuri mini Bs.

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Quando Omni Flunkus Moritati

Yup, another vote for the B14 series. The 1/2A6-0 was also nice for a second stage on 3-stagers such as the Farside. Boosted by a B14-0 of course.

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Craig, I was thinking APCP delays. They're much more user-friendly for drilling AND safety. But thinking about it further, that might add too much cost - I imagine a BP delay is much cheaper to make than APCP. But for ease of adjustment, using a tool such as a peach pitter or Cesaroni's DAT is quite easy. Conversely, according to Murphy, if you give the user three different thicknesses of delays, there's a 97% chance he'll put together the wrong combo :)

Seriously, your idea has merit, but I'm concerned about blow-by. More parts means more chances for failure. Although even having one user installed delay piece still provides a failure point.


BR,
Doug

Carl, you did indeed enter your vote, right? I'm a little concerned - the builders are leading the flyers 5 to 3. Makes me wonder about the virility of some of Ye Old Rocketeers :)
Doug

You're thinking like I do. I'm more enchanted with the idea of flying three stages - and actually viewing all three - than I am with using staging for performance. The B14-0 gets the heavy (well, it's heavy once all three motors are loaded) Farside moving without putting it in orbit (ala a D12), the 1/2A6-0 provides the drama of a middle stage without going out of sight, and the user still has the option of A8-5, B6-6 or C6-7 in the sustainer. (I even have a couple of B4-6's for something a little different.)

While my DARS brothers will tell me to wear a skirt, I plan to fly my Comanche on a C11 to A10 to Axxx combo. I see this combo as being the modern day equivalent to the B14-1/2A
booster combo above. I flew my Tridget the other day similarly. A10 to 1/2A to 1/2A. If I coulda put a 1/4A in the 2nd stage, I woulda. I just want to see it stage, not get to the moon

Maybe someday I'll do the D-C-C in the Comanche, but altitude doesn't really excite me, especially when I can't see it. I'd much rather keep it low and observable. It's kinda funny...I lawndarted my L2 attempt last fall, but I still get lots of comments on the flight. The heavy, 6" rocket went low and slow, so everything was plainly visible (including the inadequate ejection charge) to everyone there. Hopefully I can repeat it but with a proper chute deployment next time

Doug

Ya know, I've been thinking about cloning the Farside or Farside X. (I just have to get over my Midget fetish first :)

Anyway, I think the 1st stage can be converted to 24mm motors enabling the C11-0 to be used. It seems like a reasonable substitute for the B14. Others thoughts? Do the booster fins really need canting? IE, does it really need to spin for added stability?

I'm thinking C11 to A10 to A8-5 will make for a decent flight. Yeah, I know, the A10-0T is de-cert'd. Unless you accidentally write down B6-0 on the flight card :)

Doug

I voted "Groupies". No worries here!

If there is a god, I won't be anywhere near Texas when this happens.