Thanks for the motor codes, Bernard. Robert Watson of buyrocketmotors.com is our "local" supplier. I will have to see what he has in stock.

Chas

__________________
Charles Russell, MSgt,USAF (ret.)
NAR 9790, Lvl 1
SAM "Balls Three"

Chas,

As I noted to Lee a little further up, I only have measured delay data on one C12-4. Also, I have flown C12-6s from three different date codes and have seen ~7s delays with all of them. So I wouldn’t make too much out of any given lot number.....

That said, if you can get some from other batches and fly them with AltimeterThree or some other accelerometer-based device so you can get the actual delays in flight to compare, that would be useful data I think.

When you talk to Mr. Watson....ask if he has any of the As and Bs that were made after the casing dimensions fixes were done. I’d be interested in a few B4s that I didn’t have to peel the labels from (and remove half the powder from the ejection charge) to use.

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

Winston over on that other forum is trying to consolidate Q-Jet info and I spent a little time writing a post there, so I thought I'd post the same info here, so here it is:


Well......I just counted up my log entries. I've flown 42 of them so far. I flew the first one on June 1st last year (an A3-4) and yesterday (a C12-6).

Good stuff:

I love the smoky black exhaust and the relatively subdued sound.

The supplied igniters (sorry - "initiators") work well on anything from a little 9V battery-powered launch controller (Estes Astron II) or 4AA cell controller (Electron Beam) and up. I think I've had two misfires in that time frame.

The motors come to thrust very quickly, and the Cs and Ds increase from there, which is striking visually - seeing the rocket accelerate going up - especially on the Ds.

Packages of two motors include the parade-float-tissue wadding that Quest has supplied before but in a bright orange color. There's enough in the packages for two flights of models up to about BT-60 in diameter. I don't know what comes with bulk packs as I've not yet gotten any of those.

The Cs, in particular, outperform their black powder competitors (noticeably higher altitudes on the same model - on the order of 15%).

The Ds are baby Ds (certified at a bit less than 13 N-s), really a "C+" but with the progressive thrust curve they give larger LPRs (think Big Bertha) a real extra kick.

The labels are bright and easy to read and have a sort of retro Enerjet look.


Not so good stuff:

The fit issues (diameter and the size of the hexagonal portion that contains the ejection charge) of the first production As and Bs are well documented, as are the killer ejection charges. All of these things can be worked around in various ways. The real issue now is that there are (apparently) still lots of these out in the distribution pipeline. If the motors have a date code on them before September of 2018, be prepared to peel labels and clean the resulting sticky cases. Also pulling out the little red rubber plug that retains the powder for the ejection charge and removing about half the powder might save small models (BT-20, BT-50 based). I have not yet seen As and Bs in the redesigned cases....

Delays are still inconsistent and tend to run long. I've flown a number of 6-second delay motors that had actual 7 second delays (per AltimeterThree aboard the model). On the other hand, the C12-6 I flew yesterday had a 6.25s delay - close enough. There also MAY be some mislabeled (with respect to what delay they have) motors out there from recent production. There's no way I know of to find those except by flying them.


Just different stuff:

The As and Bs, even though they are certified to be at the top of the total impulse range for those classes, do not perform any better (altitude measured in the same model) than their Estes counterparts. The Cs, as I mentioned above clearly outperform Estes Cs (and Quest BP Cs).

The redesigned cases are still a little snug and if you have a motor hook in your model you MAY have to rotate the motor as you install it to find a spot where the ejection charge housing will go past the top of the hook. Keep trying - you'll find a spot that works.

The currently-supplied method of retaining the initiator - a bit of small-diameter heat shrink tubing jammed in the nozzle alongside the wiring - does work OK. The old-school little-ball-of-wadding retention method works of course.

Speaking of initiators - these are, of course, composite motors and are lit at the top like all the others. That means the initiator goes in a long way relative to a BP motor. One has to be aware of that, and not jam them in as hard as one might do with an Estes igniter/starter and take a little care to get them in the propellant slot. The tips are not as rugged as Estes types (or Q2G2s)

Current C & D ejection charges are marginal for a model with a full length BT-60 body and no stuffer tube (think the reissued Citation Patriot, for example). This manifests itself more with an over-long delay, so that the model is coming down at a good clip before the charge fires.


Well, that's what comes to mind right now, anyway.

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

Thanks for posting this info here on YORF as well, Bernard.

__________________
Scott D. Hansen
Ye Olde Rocket Shoppe - Your One Stop BAR Shoppe!
Ye Olde Rocket Plans - OOP Rocket Plans From 38 Companies!
Ye Olde Rocket Forum
WOOSH NAR Section #558

You're welcome, Scott.

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

Also....I emailed with Karl at Aerotech about the C12-4s with 7 second delays (posts 312 and 313 above) and it was from him I got the idea that there are some "at large" that have been mislabeled. However I immediately wrote back asking if they knew what date codes were involved, he has not yet replied. It's been a couple of weeks....

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

I second your efforts--compiling all of the information, positive and negative, about the Q-Jets can only help Quest--and model rocketeers. Also:

The less-desirable (with their fit problems), early-production "A" and "B" Q-Jet motors could be used in motor-ejecting models (Semroc, Squirrel Works, etc. clones [and near-clones] of classic Centuri, Estes, and AMROCS kits such as the Lil' Herc II, Hummingbird, Hawk, X-24 "Bug," Astron Falcon, Centuri Swift, etc.) and in minimum-diameter streamer- and parachute-recovered models, especially those that utilize friction-fitted motors, and:

For motor-ejecting models, a small streamer (with an attachment cord, perhaps thin Kevlar cord) could be tied around either the nozzle or the forward hexagonal ejection charge housing, to ensure that the spent motor casings descended slowly enough to be safe. This would also make them readily find-able on the ground, to keep the flying field un-littered (because plastic motor cases, unlike rolled-paper ones, don't get soft and biodegrade after exposure to the elements).

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

Jason, the early ones (from last May) will go in most models with the label removed (and the label glue residue also removed). Some motor hooks' upper ends project too far to get the ejection charge canister by them, some don't. With the labels on they won't go in BT-20 at all and are quite snug in ST-7.

I've basically taken the labels off of almost all my earlier ones, re-marked them with motor designation and date code with a silver Sharpie, and also removed roughly half of the ejection charge's black powder (by weight).

The only ones that haven't gotten that treatment are a pack or two of B4-6s with May 1 date codes. I figure they *might* be of interest to a collector some day being first of type, and based on the ones I have flown, I really don't have any single-stage models for which a B4-8 is really suitable. That's too long a delay even for something tiny like a Viking or Wizard.

I haven't purchased any As or Bs recently as I have no way of knowing when they were made, and I only want ones made after September 2018.

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

Thank you for this information. Hmmm...B4-8 motors might work well enough in nose-blow recovery models (Stine used a Viking or an Akela-1 to illustrate this type of model in his "Handbook of Model Rocketry"), and/or in the Estes Plans Book break-apart recovery model designs (one or two of which you built a few years ago). In either type of model--nose-blow or mid-body separation break-apart--a 1/2" or so wide strip of metallized mylar streamer material could be "threaded onto" the shock cord, to serve as a narrow and low-drag streamer to enhance the models' visibility after ejection.

__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see:
http://www.lulu.com/content/paperba...an-form/8075185
http://www.lulu.com/product/cd/what...of-2%29/6122050
http://www.lulu.com/product/cd/what...of-2%29/6126511
All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com.
NAR #54895 SR

Oh now there's a thought. I have a Mitosis, built from an old MRN plan. Hmmmmmmmmm......

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