Keep on posting Bernard, while us Canadians continue to pine away , waiting for the Q Jets to become available in Canada. The ASSC NAR section 794 would love to try out the C12 and D16's in some of our heavier models. I was able to pull some old Canaroc B18 motors from my stash and the kids were amazed at the acceleration. So the Q-Jets will be really impressive when they become available.

Garth Illerbrun
NAR 26894 L2

I flew 10 Q-Jets today - 5 C12s, 5 D16s.

Some thoughts....

No ignition failures with these 10. I used the supplied initiator and the little bit of heat shrink tubing retainer in each one. Ignition system is an Estes PSII launch controller with a small 3-cell LiPoly battery inside. Several of them "stuttered" once before taking off - which I had not seen with any before (or at least not noticed). But there was only a fraction of a second between the initial bump and getting off the pad in a hurry.

A number of the flights were made in one model with an AlitmeterThree aboard. Those data tell me that the Cs (marked -4 and -6) all had delays that were 7-7.5 seconds long. I will be getting in touch with Karl at Aerotech about that.

The two Ds I flew in that model were very close to the marked delay (-6). I also flew a Big Bertha twice on D12-4s. I think this will be a favorite motor for this model (at least as long as one wants to see a Big Bertha get going RIGHT NOW instead of the majestic slow liftoff one expects). That motor took the BB in question to 819 feet on one flight and 769 on the other (per a FireFly aboard). That's about double what I see with an Estes C6-3. Deployment was right at the top for both - but in one case it took most of the fall for the chute to get all the way out and open.

With the dimensional changes they made, these motors fit in models that had no special accommodations made to allow them to fit....though some fussing with getting the ejection charge container past the top of a motor hook is still in order. But it does work.

Even in the chilly air the additional total impulse of the Q-Jet Cs over Estes ones was evident in higher measured altitudes.

The black smoke while the propellant is burning kind of spoils one, but then the coast phase has very little tracking smoke until just before ejection....so as fast as these make a light model move, it makes tracking them "interesting". Jim Pommert was also at the field today and he flew a Quest Starhawk on a D16-8. We both lost sight of it once it burned out and did not see it again until after it landed.

I have not yet seen any As or Bs with the redesigned-to-actually-fit-in-your-model cases so I can't comment on how they fit or if their ejection charges have been toned down over the initial ones from last May.

If anything the Cs and Ds have ejection charges that are adequate. I've had a failure-to-fully deploy in a BT-60-based model twice now. As I mentioned in a previous post, I had my Citation Patriot almost crash some months ago (an overlong delay and therefore partial ballistic return doesn't help get the nose cone off when the thing finally fires). And the n there was the Bertha today....though in the latter case the 'chute did finally pull loose far enough and open in plenty of time. But that one was deployed pretty much at apogee (D16) rather than way late (C12). I need to put a couple of these through a BT-55-based model and see. There's plenty for BT-50 (Nova Payloader - which is what was carrying the AltimeterThree on 9 flights today - though I forgot to start the recording for one of the D16 flights).

If we can get C12s with delays that are closer to labeled values then I will look forward to flying many more of them. And the 25% more total impulse of the D16s gives a nice extra kick to models that are a little "meh" on an Estes C6 without having them land offsite as they might with a full D (D10/D21) in them.

My biggest takeaway from today's flying was "darn - the C12-4s ALSO have 7 second delays!" The rest I really already knew from prior flying and just had it reinforced today.

Happy New Year!

Thanks Bernard. A very interesting report. Do you have the date code on the C12-4s that have the seven second delay?

How’s this?

Has anyone done any electronically activated staging with composite motors similar to this? What electronics did you use? I think a Raven would do it.

Jerry

http://v-serv.com/usr/kits/record_breaker.htm

It might need to resemble this to acomidate electronics in the booster stage:

http://v-serv.com/usr/kits/tandemgoodness.htm

If Quest sold and/or has in inventory a large number of these "longer-than-advertised delay" composite motors, would they necessarily have to scuttle the whole batch of them? If they're otherwise reliable, it would seem that they could re-label them with their actual delays (stamping the motor cases' decals, including 'ERRATA slips' in their packaging [or affixed to it], etc.). As long as their actual delays were known, modelers could adjust their kits' motor choices accordingly (this information could also be included with or on kit packaging, on the Quest website, and so on).

I flew a C12-6 at NARAM that Gary gave me to try. It seemed to be spot on for delay. I was about to buy some C12-4s, in addition to -6s, and D16s. I’m glad I held off until this gets corrected.

Lee,

Bear in mind that I have an actual delay measurement on only one C12-4. The other one I flew yesterday (in a Big Bertha) looked “about right” (there was a FireFly aboard that model, so no accelerometer-based data). But do be prepared for the delay to possibly run rather longer than you’d expect with an Estes motor (or even a Chinese Quest BP motor).

I did just now send my note with data from all Q-Jet C and D flights I’ve flown carrying an AltimeterThree aboard (and so have measured ejection delays for) to Karl at Aerotech.

I see Chris’ Rocket Supplies and JonRocket have a bunch of Q-Jets in stock. I guess I need to order some more and do some more research flying.....

Bernard,

Belleville Wholesale also has Q-Jets.

I just looked, prices are still pretty low:

C12s, $5.99/pack
D16s, $7.19 / pack

Last month I dropped some into my cart, but shipping was pretty high (14.99), but depending on how many you plan to buy, might be best price around. I tried adding more and more, and by the time I got to over $100, where I was hoping for free shipping, it was $23.99

I'll have to look at that. I have no personal experience with them. I AM learning to check the price including shipping. No Amazon Prime for Q-Jets that I know of... :D


(As I wrote that I went over to Amazon in another tab and found that Q-Jets [As and Bs] ARE available on Amazon - from Belleville Wholesale Hobby - for full retail plus $6.25 per pack shipping!)