Motor Ejection instead of Electronics

[JP Morgan]

Hopefully I can attempt my Level 2 Certification this Spring. My plan is to build and use the LOC Warlock with a 54mm motor.

I was planning to launch a LOC Magnum 3, with electronics for the deployment but changed my mind
for several reasons. The plan was to use a 54mm motor, the Aerotech K550 W, a 4 grain motor. So I
made the purchase of a 54/1706 complete case and I also have the Spacer Kit.

I intend to use a 54mm J Motor in the Warlock, one with only 2 grains, the Aerotech J460T-14A. So I placed an order with
csrocketry.com for a 54/852 complete case, 2 grain case, because I'm not certain about using the 4 grain case with spacers
for the motor ejection with only to grains!

I've got FFFF black powder so the ejection will go BOOM!
I just got the feeling that using the spacers in the 4 grain case and only 2 grain load was not made for motor ejection but
using electronics for deployment...?

If I use a K550 4 grain motor in the Warlock the apogee is around 4,000 feet!!! That's cool and all but Not something I want to try for
my Level 2 Certification Flight!

 

[JohnCoker]

You can get a quick idea about many different motors for your rocket on ThrustCurve.org. For example, Eric Lynn created a Warlock with a 54mm motor mount that might give you more ideas:
https://www.thrustcurve.org/motors/guide/5ff215d034e9ac0004d6a104/summary.html

 

[mo2872]

The 38mm motors work fine with spacers and motor eject, don‘t see why the 54mm wouldn’t. If that’s what you’re asking, anyway.

 

[JP Morgan]

The 38mm motors work fine with spacers and motor eject, don‘t see why the 54mm wouldn’t. If that’s what you’re asking, anyway.

Yes, that's what I was pondering!

Thanks guys!

 

[Jee3300R]

The 54mm RAS definitely won’t effect the ability to use ejection on 54’s as long as the floating closure isn’t plugged.

 

[Voyager1]

I haven't used the K550, but have with the J460. My only advice here is for you to go lower and slower when attempting a certification. I see too many flyers using unnecessarily powerful motors when certifying. Why take the risk? I would also use motor ejection as a backup if you intend using electronic deployment.

 

[CPUTommy]

Dumb question.. why not just use a reload as is ? You can adjust the delay, remove it and use electronics, etc. Seems like your motor is complicated for a L2 attempt..

Get ur L2 THEN play...

Either way.. good luck and if I can help in any way shoot me a message. Tom

 

[ZEDL1]

JP, I earned my L2 Certification many years ago, 1992 or 93 as I remember, flying a fiberglass Dangerous Dave's 4" Mad Dog (older members will remember that manufacturer) using an AT K550 long delay, motor deploy only. Altitude was somewhat higher than 4000'... Electronics were not common at that point in the evolution of our hobby. My flight was perfect with a perfect recovery. One shouldn't fear motor-deploy only. If carefully prepared, it works just fine. I suspect that some will remember that in those days, it was all that we had and we made it work. The development of such a depth of availability of electronic options has been amazing. That said, I still use motor-deploy only more often than electronic recovery. I'm very comfortable with it.
Best of luck with your L2 Cert flight.

 

[OverTheTop]

I see too many flyers using unnecessarily powerful motors when certifying. Why take the risk?

Because we have the choice. I personally have certified on I, K and N (I actually considered an O) motors because I don't see any point of just putting in enough Ns to get me just over the line. I like a little more challenges.

Would I ever criticise anyone else for certifying on a smaller motor? Never. If they are within the rules then it is acceptable.

To the OP: Have you considered doing electronic ejection with motor backup? Once you have done electronic and discovered how repeatable it is, unlike drilling delays, you will likely be a convert.

 

[JP Morgan]

Excellent reading here!!! All the replies are very good information!

For now I plan to use the 2 grain case for the J460-T-14A. I'm considering like a 7-8 second delay
and to use the Jolly Logic Chute Release, opening the chute like 500 feet.

I'm also thinking about using a streamer to slow things up a bit.

I find myself spending a lot of time on the web site ThrustCurve.org thanks for the reminder John!

Thank you very much guys for all the great information and your experiences!!!

JP

 

[Bowman]

...My only advice here is for you to go lower and slower when attempting a certification. I see too many flyers using unnecessarily powerful motors when certifying...

Good advice!
J275 is just as much an L2 motor as an "L". You can always and should inch your way up to the big motors.

 

[Voyager1]

Good advice!
J275 is just as much an L2 motor as an "L". You can always and should inch your way up to the big motors.

Our club has always promoted a policy of incremental advancement through the certification levels. Get some experience on all motor grades as you progress. While this is not mandatory and, yes, you do have a choice, it has worked well for us and there is no compelling reason for changing our advice to certifying members.

 

[dpower]

Our club has always promoted a policy of incremental advancement through the certification levels. Get some experience on all motor grades as you progress. While this is not mandatory and, yes, you do have a choice, it has worked well for us and there is no compelling reason for changing our advice to certifying members.

A wise policy, especially with the occasional "What rocket kit will work for both L1 and L2?" question.