PML 3.1" Bull Pup for L2

[sharkbait]

On the H128, I hit 256mph (JL Alt 2)...the J seems to get a lot closer to Mach 1 (OR shows error at extreme speed .

The goal is to try it and see what happens. I have a 4in Goblin ready for L2 as a backup, but I may cert on the Gobby and build up the Pup's fins and then try it.

The only reasons I can think of to not use your L1 rocket for an L2 attempt are:

1. Rocket was not built to handle the flight stresses of a J motor

2. Rocket design would break the waiver on a J motor

3. Rocket altitude without DD or JLCR would most likely result in recovery outside of the club recovery cylinder

4. Rocket MMT is too small to accept a J motor

Other than that have at it and have fun

 

[Capt. Eric]

The only reasons I can think of to not use your L1 rocket for an L2 attempt are:

1. Rocket was not built to handle the flight stresses of a J motor

2. Rocket design would break the waiver on a J motor

3. Rocket altitude without DD or JLCR would most likely result in recovery outside of the club recovery cylinder

4. Rocket MMT is too small to accept a J motor

Other than that have at it and have fun

You left out the biggest reason of all to use a different rocket. It would go something like this:

Wife: "You just built a rocket for that last level thingy. Why do you need ANOTHER one?"
Rocketeer: "But honey, THAT rocket was for my Level 1. THIS rocket is a Level 2 rocket. It's TOTALLY different."
Wife: "I don't see how it's different. It's just bigger and more expensive, but it looks the same to me."
Rocketeer: "That's just because you're not a rocket surgeon like I am. Trust me. It's TOTALLY different. The other one had 3 fins. This one has 4 fins."
Wife: "Whatever. If you're getting that thing, I'm getting a new pair of shoes!"
Rocketeer: "Deal! Just make them hiking boots. I'm gonna need help retrieving that new rocket."

 

[ljwilley]

Using the same rocket "to save money," tells me this is the wrong hobby for the person. We've heard all the other excuses, too.

If someone wants to save money, let them do so. There is no problem with that.

 

[cls]

One does not need an excuse. If you want to use the same rocket, you just do it. It is nobody's business why you made that decision.

Ok if it passes muster with the RSO.

Look, don't jump all over me about this. The question was, one club said use a different rocket, is that common? I said most clubs around here strongly discourage using the same rocket for both L1 and L2. For reasons. That's it.


Personally, I agree, in most cases. Some folks really don't know enough to make it work, and don't know enough to know what they don't know.

On the other hand, we have safety distance rules, either they are sufficient or they are not. In which case we should work on improving them.

 

[soupmanrmc]

You left out the biggest reason of all to use a different rocket. It would go something like this:

Wife: "You just built a rocket for that last level thingy. Why do you need ANOTHER one?"
Rocketeer: "But honey, THAT rocket was for my Level 1. THIS rocket is a Level 2 rocket. It's TOTALLY different."
Wife: "I don't see how it's different. It's just bigger and more expensive, but it looks the same to me."
Rocketeer: "That's just because you're not a rocket surgeon like I am. Trust me. It's TOTALLY different. The other one had 3 fins. This one has 4 fins."
Wife: "Whatever. If you're getting that thing, I'm getting a new pair of shoes!"
Rocketeer: "Deal! Just make them hiking boots. I'm gonna need help retrieving that new rocket."

She says pretty much this!

 

[soupmanrmc]

The only reasons I can think of to not use your L1 rocket for an L2 attempt are:

1. Rocket was not built to handle the flight stresses of a J motor

2. Rocket design would break the waiver on a J motor

3. Rocket altitude without DD or JLCR would most likely result in recovery outside of the club recovery cylinder

4. Rocket MMT is too small to accept a J motor

Other than that have at it and have fun

I overbuilt it with the original intention of giving it a go. A J350 could work (38mm motor mount). Used the JLCR on a G77 and L1 using H128, so I definitely am using the chute release on all my birds expected to hit ~1,000ft+.

Overall, I am a bit nuts but insane (so much, anyway). Going to use the 4" Goblin just to get to L2, then perhaps get the Pup up on a J after building up the fins a bit!

 

[loopy]

Ok if it passes muster with the RSO.

Look, don't jump all over me about this. The question was, one club said use a different rocket, is that common? I said most clubs around here strongly discourage using the same rocket for both L1 and L2. For reasons. That's it.


Personally, I agree, in most cases. Some folks really don't know enough to make it work, and don't know enough to know what they don't know.

On the other hand, we have safety distance rules, either they are sufficient or they are not. In which case we should work on improving them.

I believe most people took issue with your statement that you had heard all the "excuses" on why people want to use the same rocket for both certs. May not be how you intended it, but it sounded rather elitist.

 

[cls]

I believe most people took issue with your statement that you had heard all the "excuses" on why people want to use the same rocket for both certs. May not be how you intended it, but it sounded rather elitist.

You're right.

 

[DaHabes]

Using the same rocket for your L1 and L2 brings up a question that may be pertinent to this thread

One of the certifiers in the local club says that you have to use a different rocket for your L2 than you did for your L1. There was one person planning on using a Zephyr for his L1 then adding the Apogee dual deploy kit for his L2 and the certifier said that would be against the rules. Has anyone else heard this?

-Bob

Whether you use the same rocket for L1 & L2 vs. two rockets is irrelevant. The rules don't require two different rockets, not does L2 require a dual deploy rocket. In my case I flew my L1 on a Madcow SuperDX3 single deploy with the plan to use dual deploy for my L2. Then I reasoned it would be just simpler to get my L2 using a Chute Release and avoid the complexity of dual deploy, so I flew my Loc Minie Magg on a J. THEN, I made my SuperDX3 dual deploy and started practicing with I's & J's in it (and a couple other RDD rockets I built). Now I'm building my L3. The journey is what you make it.

So, 1) anyone who says you can't use the same rocket for L1 & L2 doesn't know how to read, and 2) there is a reason why L3 requires supervision. A L3CC or TAP won't approve your build without a solid design AND sufficient experience. Follow the rules, as written, and make the journey your own.

 

[soupmanrmc]

Thanks everyone for their input and feedback!

I went with a LOC 4" Goblin build on a J350. Successful at 2724 ft and 505 mph. JLCR a bit early at 560 ft (set for 500), but not complaining.

Thanks go out to the great team at TRA ICBM and NAR ROSCO at Freedom Launch 2024!

 

[OzHybrid]

I just finished L1 with the Pup, and I would like to give it a go for L2 with a J350W 38/720. I have heavy duty fin fillets everywhere I could (with a JB Weld). Sims at Plan on a chute release at 500ft. It sims well to just under 5800ft.

Is this a good idea, or I am a tad nuts?

I've seen someone squeeze an M in one. That was nuts.

 

[rocketryfanatic]

If you have a goal or project in mind find another tap or prefect that will embrace your goal. Some are dinosaurs. When I got my L3 years ago, me being young I just did exactly what my tap wanted me to do. I had to do low and slow. But now if I had a goal of l2 or l3 in mind I would just find a different prefect or tap.

 

[soupmanrmc]

I've seen someone squeeze an M in one. That was nuts.

Now, that would be nuts for a 3.1"...I wonder

If you have a goal or project in mind find another tap or prefect that will embrace your goal. Some are dinosaurs. When I got my L3 years ago, me being young I just did exactly what my tap wanted me to do. I had to do low and slow. But now if I had a goal of l2 or l3 in mind I would just find a different prefect or tap.

I will probably join Tripoli in a few months, definitely before I fly L3.

I will be reaching out to NAR L3CCs for guidance and mentoring with the project.

In the meantime, I will be playing with dual-deployment in several rockets and in different configurations to see which will work best (standard, head-end, etc.)

 

[OzHybrid]

If you have a goal or project in mind find another tap or prefect that will embrace your goal. Some are dinosaurs. When I got my L3 years ago, me being young I just did exactly what my tap wanted me to do. I had to do low and slow. But now if I had a goal of l2 or l3 in mind I would just find a different prefect or tap.

Previously the TRA rules stated that all scheduled events had to occur and be witnessed by the TAP. That kind of meant the TAP had to be ABLE to witness them. So certainly low and that really meant slow too.
The rules were changed so it just has to be a safe successful flight. Recovered and brought for inspection. Usually, the TAP will go with you to the recovery location.
What you launch is your choice. But also remember that cloud forms at 5000ft roughly. If you set up for a 30000ft cert attempt at a remote location and it gets cloudy it can get expensive to get that cert if the weather won't play. Ask me how I know.

 

[soupmanrmc]

Previously the TRA rules stated that all scheduled events had to occur and be witnessed by the TAP. That kind of meant the TAP had to be ABLE to witness them. So certainly low and that really meant slow too.
The rules were changed so it just has to be a safe successful flight. Recovered and brought for inspection. Usually, the TAP will go with you to the recovery location.
What you launch is your choice. But also remember that cloud forms at 5000ft roughly. If you set up for a 30000ft cert attempt at a remote location and it gets cloudy it can get expensive to get that cert if the weather won't play. Ask me how I know.

My goal is to stay under 7,000ft, possibly a hair under 6,000ft (depending on how everything sims out).

 

[loopy]

My goal is to stay under 7,000ft, possibly a hair under 6,000ft (depending on how everything sims out).

I wouldn't think that would be an issue then. Mine was right around 6k', and everything was plainly visible.