I'll start with some of my opinions, albeit thoughts from a newbie.

My first thought is that it is important to keep the motor to a G or under to maximize participation and keep costs down.

I'd prefer a single use motor, but not adamantly. If there is a cool reloadable motor, then lets go for it.

I'd prefer not to allow tracking devices if we can keep the expected altitudes below five thousand (see motors below). Electronic tracking adds a lot of cost if you don't have a system, and finding your rocket the ole fashion way is part of the charm.

I like the open format this year, and could go either way on allowing multiple entries.

For motors, the new AT G-80 at 137 N total impulse is enticing (definitely supersonic, likely 7000'), but I think I would prefer to go the other direction. By going with a lower average impulse motor the design mass will be constrained. You will have to build light and strong, not just heavy and strong. I also think that if the altitudes can be kept in the four to five thousand range, visual tracking is more reasonable and/or you can launch in a stronger wind. I think we should stick with a 29mm motor mount. Here are some to think about:

RoadRunner G60, 77 N, 10 second delay- basically a smaller version of the G80 used this year, and a favorable delay. Optimum mass should be about 40 grams less and altitude should be about 1000' less, say around 5000'.

The AT G40, 100 N, white lightning also offers a 10 second delay. The lower average impulse will push the optimum weights lower, and max altitude will be around 5500.

The AT F26FJ is a slower burn motor, 65 N, with an available 9 second delay. This would really push the weight down, optimum weights will be in the 50-80 gram range. Max altitude in the 4500' range and velocities will mellow down to 800FPS. Black smoke might help the tracking.

And to think outside the box a bit more, the new RoadRunner E25 is a full E class motor that would lift a light 29mm airframe to about 3500'. Not as much woosh, but the least expensive alternative and the most likely to be recovered.

In a reload, the AT F40, a 100% F class motor, White Lightning, offers a 10 second delay. Optimum mass will be below 100 grams I think, so some challenge there. Altitudes will be about 5000'. The casing is $50, but many people probably already have the AT Hobby case 29/40-120

The reload AT G64W, at 112 N is a popular motor, quite similar to the 2008 RoadRunner G80. If you like red instead of white, the G71R at 108 N is a substitute.

How about the Apogee F10? A local vendor, a VERY constrained mass, tight design requirements a given... and the possiblity of 7K or 8K given the 8.5 second burn... The motor is cheap too.

Just throwing an idea out there, not necessarily my favorite.

W

I think that using a lower-impulse motor that would keep it in the visible range is a great idea. That way, we can leave it up to the competitors as to whether they want to deal with the hassle of a tracker, and it would really lower the barriers to entry.

Using the F10 would be cool from the standpoint that our club would likely break the Tripoli world F record 2 or 3 times during the course of the contest, since there's about 2500 feet of headroom above the record for an optimal F10 rocket when launching from the North site. On the downside, a good F10 altitude rocket goes out of sight before the motor stops burning. The 8-second motor ejection delay is too short, and if it has any tracking smoke, I've never seen it. (o.k., except for the 2 I flew last year that were on the ground during the tracking portion 🙄 ) So the winning bird would require electronic apogee deployment and a tracker.

So my vote would be for the Roadrunner F60.

Above D impulse, I do believe you would have to do electronic deployment to get maximum altitude in an optimized design - I think that's a given. For every altitude record I have chased from E on up, electronic deployment was necessary since no motor had the length of delay needed.

Warren

I was able to time two of the RoadRunner G80 launches. The first had an actual delay of 12.5 seconds (14 seconds from launch), the second had 11.5 seconds. Seems like the G80 10 second delay is conservative, and perhaps the F60 also. If this delay bias is consistent, it makes the RoadRunner F60 product an almost perfect delay- 12 seconds.

The Apogee F10 series does not have a plugged version, so electronic apogee deployment would require surgery on the motor to remove the charge, or some sort of vented chamber. And yes 8 seconds is a bit short. We probably don't want to set up a contest where the winner monkeyed with a certified motor. BTW, the RoadRunner E25 has both a 7 second delay and a Plugged option.

The AT F26 single use motor has only 65 N impulse but a 9 second delay, which is favorable also. Followed by the AT F40 reload, Apogee F10, RoadRunner E25 (but perhaps better if the delay is conservative), AT G40 Single Use, AT G80, and AT G64 with the least favorable delay. Or at least that's based on a few data points out of rock sim with weight optimized designs.

I think we will be fine with most of these motor delays, though the least favorable one or two motors should probably be avoided. It will only make a 200' altitude difference, and as long as deployment isn't at 200 FPS where parachutes are being shreaded haphazardly, the playing field will still be even.

Keeping the motor to G's or under allows EVERYONE a chance to play if they desire to do so. I'd prefer a closing date for entry - single shot - pay in and take your chances - closed to all newcomers after first declared flight. Tracking whatever way you choose. Possibly alter the contest a little and require a specific weighted payload like a water balloon or eggs. Just thoughts on my part. I still feel that the majority of club members, unfortunately, do not pay attention to the Forums and therefore, decisions need to be made for membership and presented already determined at the meeting. Then members can decide for themselves, Yea or Nay to play.

I ALWAYS plug my single use motors that I use for altitude shots. Pull the paper seal, dump the black powder and fill the hole with a bit of epoxy. On some motors I've epoxied in an screw-eye.

Warren

i'm new around here, but now a member and do intend to participate in SSS in 2009.

I think that SU motors are preferable given the number of missing SSS rockets at just three launches i went to this year.

If a reload is done, do the F40 or G64 or support Tim with the 38mm G79 Cesaroni. Avoid any of the 24mm F motors IMHO, because many people do not own the 24mm AT casings, which will drive participation down. I happen to own and really like the 24mm, but I think for drawing participation it is not a good choice.

Cheers,
-bryan

What if the rocket used for the G shot also had to be the same rocket used for the J shot and you got to combine altitudes for a grand total? Two shots at one prize.

What if the rocket used for the G shot also had to be the same rocket used for the J shot and you got to combine altitudes for a grand total? Two shots at one prize.

I think that is a GREAT idea, though it would limit things to L2 flyers. We could call it the SSSSSSS 😆

Any other support for this idea? small motor and big motor in same rocket? Even if we did an F and an I, or a G and an I (which would mean all L1s could play). Very cool idea...

Except for the first year of the Single Shot Sweepstakes, we have focused on single use motors. First the Aerotech G80 and then the Roadrunner G80. Personally I feel that given that this is an altitude contest, the single use motor is a better choice for a number of reasons:

1- Less weight than a reloadable for the same amount of impulse thereby giving additional altitude to the flight or at least the potential.

2- More importantly, it is less expensive to lose as so many have lost their SSS birds - I've lost two. Losing the altimeter is bad enough - compound that with the loss of a motor case and perhaps even a radio tracker as well.

What if the rocket used for the G shot also had to be the same rocket used for the J shot and you got to combine altitudes for a grand total? Two shots at one prize.

HEY!!!
I LIKE THAT!!!!!

The Double Shot idea is interesting, but if the selected motors were too widely spaced, say an F and an I, the obvious choice would be to optimize the airframe for the bigger motor. The smaller motor would be a bit anticlimactic I'm afraid, and the difference between a good design and a bad design would only be a few hundred feet on an F motor.

The "Double Shot" idea is very intriguing as well as lending itself to some potentially unique rocket names and/or graphics.

Double shots could be related to Alcohol, Firearms and Explosives. Too bad we can't cover Tobacco or perhaps we could get the ATFE to sponsor the contest.