Onyx by Loc

I've never lost site of my Onyx, even with the H54. I'm not sure how high it went because I didn't use an altimeter. Wouldn't be hard to find out. The Onyx can handle just about anything that will fit the 29mm motor tube. Definitely start with the F motors. It will fly great. It will also handle the bigger ones as well. It's a versatile, fun rocket. Enjoy!

Hmmm. I wonder how it would do on the AEROTECH 29MM HP SU DMS MOTOR - I205W-14A or the CTI Pro29 382I243-13A?:dark:

That's the fun of forums, sometimes. getting off topic. I have seen some miracle on field recoveries at Berwick, ME. One time it was very windy, just under the 20 MPH limit. Some guy puts up a rocket on a J. I'm thinking he can kiss this one goodby. It ended up landing closer to the pad than my Estes Hornet on a B6-4! I appreciate everyone's input. The technical information all seems to be on the same page.

+1, sometimes I don't review preceding pages and forget where the topic started.

5:1 is a great rule of thumb with nice margins. e75 would be a fun flight if you have a solid adapter.

We had someone run some Rocksims for us. The F20 took it over 1,000 feet. My friend is concerned that might be too much for a first flight. He wants to start with the E20. We have the 29 to 24mm adapter. I made a thrust ring for the it. For retention we have two 6-32 inserts in the aft centering ring. Now we just have to make some clips. If he just wanted to go with the 29mm motors we could have used the Estes Pro Series II plastic retainer. Works well on three models I have.

Ok, sounds like it's low and slow with the E20. What does Rocksim say for that one ? Maybe you already covered this:

Enter your launch site's elevation.

Sim it with the flight ready weight of your rocket.

Sim it with the actual length of your launch guide (rail or rod).

Sim it with some wind, I usually set 10mph.


Good luck and please give a flight report.

I don't have my data with me right now but Sim said an E15 will go 812 feet but the thrust to weight ratio is only 3.7. I can't understand how Loc can list a D12 engine as suitable for the Onyx? Launch date it scheduled for July 15, 2017 in Berwick, Maine. Hopefully my friend will get the fins on this week so that he can paint it. Instead of the 15 inch chute that come with the Onyx we are thinking of going with an 18 inch chute. For the last two years I have been keeping a log of my flights. Data includes weather, engine, chute size and comments about the launch. I also have a chart of what my rockets weigh. All that information should provide a good baseline for engine and chute selection. Rock Sim is fine but there is nothing like real live data.

If you build the 24 to 29 adapter properly you can use the Estes PSII retainer.

I will take a picture of the set-up this and post it tomorrow.

deangelo54 said:

We had someone run some Rocksims for us. The F20 took it over 1,000 feet. My friend is concerned that might be too much for a first flight. He wants to start with the E20. We have the 29 to 24mm adapter. I made a thrust ring for the it. For retention we have two 6-32 inserts in the aft centering ring. Now we just have to make some clips. If he just wanted to go with the 29mm motors we could have used the Estes Pro Series II plastic retainer. Works well on three models I have.

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deangelo54 said:

I don't have my data with me right now but Sim said an E15 will go 812 feet but the thrust to weight ratio is only 3.7. I can't understand how Loc can list a D12 engine as suitable for the Onyx? Launch date it scheduled for July 15, 2017 in Berwick, Maine. Hopefully my friend will get the fins on this week so that he can paint it. Instead of the 15 inch chute that come with the Onyx we are thinking of going with an 18 inch chute. For the last two years I have been keeping a log of my flights. Data includes weather, engine, chute size and comments about the launch. I also have a chart of what my rockets weigh. All that information should provide a good baseline for engine and chute selection. Rock Sim is fine but there is nothing like real live data.

Click to expand...

A d12, being a pintled end burner, has a peak thrust of almost 30N. More, in fact, than any other current Estes black powder motor. With a long rod on a quiet day, it's got a pretty hefty initial kick, after which it settles down.

The Onyx lists at 13oz / 0.812lbs. That gives us 3.612N ( please ignore the false precision and implicit lbs-force conversion ). Times five is almost smack dab at 18N.

So if your rail is long enough, that first third of a second with the high thrust ought to get you into that quiet ( low angle of attack ) air. If your fins plus the remaining 1.3s at ~8-10 N is enough to keep overcoming gravity, air resistance, and small gusts: presto!

This is a well-engineered flight, where well-engineered means the margins were small but stable. Most RSOs should turn you away without detailed proof.

deangelo54 said:

I don't have my data with me right now but Sim said an E15 will go 812 feet but the thrust to weight ratio is only 3.7. I can't understand how Loc can list a D12 engine as suitable for the Onyx? Launch date it scheduled for July 15, 2017 in Berwick, Maine. Hopefully my friend will get the fins on this week so that he can paint it. Instead of the 15 inch chute that come with the Onyx we are thinking of going with an 18 inch chute. For the last two years I have been keeping a log of my flights. Data includes weather, engine, chute size and comments about the launch. I also have a chart of what my rockets weigh. All that information should provide a good baseline for engine and chute selection. Rock Sim is fine but there is nothing like real live data.

Click to expand...

A D12 has a 30Newton peak at the first 1/4 second. You'll have a 5:1 on anything over 21 Newtons as long as your motor weighs ~50 grams.

Were you talking about the 24mm single use Aerotech E15?
Or did you mean the 29mm BP Estes E16?

The Aerotech E15 is a light motor with ~28N peak almost instantaneously. That would work well
An estes E16 is a heavy motor and has a slow build up to 25N at 1/2 a second. I would hesitate flying that one. (But that's just me, I'm sure others would say "throw it in their and let it rip!"..)