Hmm, rather than a thin spacer maybe I’ll open the upper “centering ring” opening slightly so the QJet case can fully seat. Possible that the upper hex part of the QJet doesn’t go far enough through the center opening. I’ve been too busy the last two days to do any rocket work but now that school is out (I’ve been substituting since I retired last year - it’s a hoot! Most days ) I can do some more fiddling with the Saturn. I like the modify the rocket idea better - simple solutions are my favorites.

Scott,
I think I see what the problem is. When loading a Q-Jet, at the first "stop", try rotating slowly and see if it drops a little more. The flat part of the hex needs to line up properly to clear the ring and fully seat the motor.

I don’t think the hex-shaped ejection charge container is the problem here (as it is if the upper end of a motor hook is past a certain length) - the opening in the upper ring is plenty big enough to clear it. That said, a little twisting while pushing the motor in all the way may help.

Mainly just don’t be afraid to push it in firmly until it stops the second time and there’s ~1/8 of an inch of motor sticking out of the lower end of the mount.

__________________
Bernard Cawley
NAR 89040 L1 - Life Member
SAM 0061
AMA 42160
KG7AIE

Instead of a motor tube the engine is held in place by two plastic rings fore and aft. So when inserting the Q-Jet it is easy to slide it in slightly off center to a "stop" even though it's not fully seated. See first pic. The hex is hanging up on the ring. Twisting will ensure it is centered and seated.
I encountered another small problem even before launch: when picking the model up the upper section above the separation point broke off. The plastic bulkhead with the parachute attachment is glued to the transition shroud with two drops of glue. So it is just tacked on. I reglued it with a full ring of modeling cement. See second pic. With the forces at ejection and the snap of chute opening this could be a problem if not attended to.
But overall still pleased with this model. Hope to be even more pleased after the first launch.
Cheers.

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Not sure if this is going to be enough of a frequent flier to justify modding the shock cord setup but it doesn’t look like it would be too hard - removing the rear engine plate/bulkhead is straightforward, just Phillips screws, and that gives you plenty’s of access to attach a shock cord inside the engine compartment rather than the inside of the paper body tube liner. Though, now that I think of it, I might just need a second one to have some fun with - especially a more prototypical paint scheme, 24mm engine mount, detailed LES tower (NO, not THAT )

Hmmmmm......I’ll have to check the one I’m flying for that. It’s stayed together for three flights so far.

__________________
Bernard Cawley
NAR 89040 L1 - Life Member
SAM 0061
AMA 42160
KG7AIE

A moderate breeze, off and on. I'm going to order one tomorrow, and some D10's also.

__________________
Got a Caribbean soul I can barely control.....

I saw two of these models fly at the local launch.

The wind was variable but mostly around 4 MPH.

One of the Saturns flew with a C6-3. It worked fine but it was underwhelming and had started to arc over just before burnout.

The other Saturn had an AeroTech D10 motor. Wow! That thing really scooted!

No instability or recovery issues on either flight.

__________________
Bob
S.A.M. # 0014

At our launch on the Saturday of the Memorial Day weekend, we did have intermittent breezes. Both flights were fine under power, then went end over end. I suppose, by definition, that they were not unstable. But they were not pretty. I'm ordering both a D10-3 and a D10-5 for mine, to see if that improves the flights.

__________________
Got a Caribbean soul I can barely control.....

The fin unit and the upper half are now available as replacement parts on the Estes website. The clear PFU is tailored to attach behind a 2" tube, so scratchers can use this to make "finless" models like a 2" (fill in the blank): Gemini Titan, Mercury Atlas ( with the plastic Mercury capsule set now also available), Polaris, Poseidon, MX missile, etc. etc.
Use four short dowel pins to secure the PFU along with an aluminum 18mm retainer, or make your own.
BTW does anybody else think that it would be great if Estes sold that plastic 18mm retainer used in this kit separately? I would buy a bunch of those. Laters.