Level 3 build for LDRS 2018 (completed-vids and pics)

[Tonimus]

The first parts have arrived...

(80 pound pibble for scale)

 

[Nick@JET]

Sort of LOC Magnum shape and even a cluster! This is going to be cool. LDRS will be here before you know it good thing you're starting early.

Actually I though you already built an L3 bird a year or so ago?

 

[mccordmw]

Going to put some honeycomb sheet in those fin gaps and epoxy the whole thing? This will be fun to watch. Good luck!

op:

 

[Bat-mite]

The first parts have arrived...

(80 pound pibble for scale)

Wow! That one piece looks just like a dog! So realistic!

 

[Tonimus]

Nick, I have two L3 capable birds. A Wildman Interceptor AAD 98 and the scratch built Neutral Zone. The Neutral Zone is probably the one you're thinking of. That was basically proof of concept for this build. This won't be quite as large, but will be built using the same techniques.

Mark, I'm actually trying to figure out if Trim MonoKote is strong enough to hold up to 400 mph.

 

[Wayco]

You're gonna need a cluster to get that 80 lb. pibble off the pad!
Looking at the size of those holes in your rings, that rocket is going to cost you a lot more to feed than pibble too.

 

[Nytrunner]

The fincan looks great, but I'm really concerned about the dog's thrust to weight ratio......I don't know any RSO that would let that one through.

Query: Is a Pibble a cross between a Pitbull and Kibble?

 

[Tonimus]

Hm. I'm planning on using an M1075DM. 300 pounds initial thrust. I think he'd be stable as long as it is a calm day.

 

[Tonimus]

Since I can't leave well enough alone...

All stainless hardware, setup the same way as the last testbed.

 

[cwbullet]

The first parts have arrived...

(80 pound pibble for scale)

Dog or the rocket? That is one tired looking dog. Subscribed.

 

[cherokeej]

That's a sweet puppers! But the little feller does look tired.

And gentlemen, I have first hand experience that the specific impulse of the propellant produced by the southbound end of any pibble will provide plenty of thrust to weight for the astro-pup in question. You talk about clear a room... Evacuate! Whatever you do, don't cause a spark!

 

[Kallahan11]

You split the top fin with your screw in picture 1 BTW, just wanted to make sure you noticed.

 

[Bdpeters]

nice build, it is great to see how some of the bigger birds are put together.

 

[Tonimus]

You split the top fin with your screw in picture 1 BTW, just wanted to make sure you noticed.

Very observant. This seems to be unavoidable when putting inserts into the edge of ply. I did everything I could think of to mitigate it, but nothing worked. All of the holes are like that to some extent. However, the last rocket built with the same construction technique had the same issue and has numerous hard landings without any ill effect.

Because I'm using inserts, they have teeth that grab and are super resistant to pull-out. And since most of the joints are sandwiched between the centering rings, they have nowhere to go.

 

[Tonimus]

Motor mount tubes arrived from Apogee yesterday. The 4" mmt was a tad oversized compared to the spec online, but since I peeled the glassine off anyway, I just pulled a little more off. All the tubes have been cut down. I'm holding off on gluing until I hear back from my L3CC member. Better safe than sorry.

 

[KenRico]

Thanks for sharing - always interesting to see how a MEGA project like this come together .

What kind of electronics are you planning to use ?

Kenny

 

[Tonimus]

Kenny, I've been using Eggtimer electronics. I've had excellent luck with them (except for the GPS function, but I'm pretty sure that is related to a hard landing I had...)

 

[Tonimus]

Just an update for now. Met with my L3CC adviser. Nice guy. We talked for about 2 hours about all sorts of stuff. Anyway, he wasn't particularly thrilled with the design. He would prefer a more conservative and conventional L3 attempt. Something without fins extending past the bottom of the body tube, conventional construction techniques.

Ultimately he understands my desire to use this design for my L3 attempt. We came to an agreement that I'll document the snot out of the build, fly it on a K or L motor and prove the rocket, design, and electronics package. Afterward, I'll make my L3 attempt.

He also thinks my timeline is a little on the aggressive side to be ready for LDRS. I understand that, and logistically speaking, it can be difficult to work out doing my L3 at LDRS. Ultimately someone I may or may not have met will be the deciding factor on whether or not they'll sign off on the flight, and then there's the possibility the RSO won't like it. So for now the plan is to get my L3 cert locally. As long as everything comes together, this rocket is still coming to LDRS with me, though.

 

[Nytrunner]

Not thrilled? With what aspects? Without seeing your scheme, it looks like a straightforward 3FNC, but with hollow composite fins.

 

[mpitfield]

Wow I can't wait to see the reaction from my TAPs when I pitch my L3. Good on you for taking it in stride and negotiating something you are still happy with.

 

[Tonimus]

There are two main things he wasn't thrilled with. Mainly the bolt together nature of the design and secondarily the large fins that are aft of the rear end of the body tube. I understand his hesitation, as it is his signature if it goes up on a L3 attempt and it is a bit of an odd way to assemble a rocket like this. I don't think it is unreasonable to be on the conservative side and ask that I have a test flight before stuffing a M in it.

EDIT:

Here's how the fins and body tube will interface. The body tube will slide down onto the fin can, and then about 63 screws hold the two together.

 

[Cl(VII)]

I am all for mechanical attachment over glueing everything. I am actually more surprised that the metal angle used to bolt the fins on is ok.

Nice project, and I'll be watching with interest.

 

[Tonimus]

I am all for mechanical attachment over glueing everything. I am actually more surprised that the metal angle used to bolt the fins on is ok.

Nice project, and I'll be watching with interest.

Thanks, Chris. The aluminum angle is actually aesthetic. The fins are more than strong enough by themselves. But aluminum "fillets" look cool.

 

[Cl(VII)]

Thanks, Chris. The aluminum angle is actually aesthetic. The fins are more than strong enough by themselves. But aluminum "fillets" look cool.

I agree they look cool. I'm just surprised you didn't get dinged on the metal parts prohibition. If your L3CC says it's cool then great. They do look sweet.

 

[Tonimus]

I agree they look cool. I'm just surprised you didn't get dinged on the metal parts prohibition. If your L3CC says it's cool then great. They do look sweet.

Did I miss that prohibition? That's a thing?

EDIT: Duh. The lightweight materials. I generally interpret that to mean aluminum is okay. Like you said, if my L3CC says it is good, than we're good.

 

[MikeyDSlagle]

Uh oh. Now here comes the metal parts discussion...again. Not you Chris, but someone will chime in with some nonsense about a core sample or something. It's been L3CC adviser approved already so hopefully that will stall that discussion.

This is an interesting build. I tip my hat to you sir for having the patience for all those screws. I am all for using fasteners rather than glue everything. I just lose patience with the splitting and all the aligning..ugh. I'll be watching.

 

[fyrfytr310]

No metal. Ever. Terrible design.











Just kidding. Looks cool!


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[Bat-mite]

Does kind of raise the question ... has anyone ever been in the situation where the L3CC/TAP approved the flight, but the RSO said no?

 

[fyrfytr310]

Does kind of raise the question ... has anyone ever been in the situation where the L3CC/TAP approved the flight, but the RSO said no?

Good question. I lived in a world where the RSO was one of my TAPs. I would have been more than a little upset if he denied permission to fly

I'll bet it's happened though.


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[Cl(VII)]

Does kind of raise the question ... has anyone ever been in the situation where the L3CC/TAP approved the flight, but the RSO said no?

Yes. My L3CC told me about a guy who had that happen. Flyer and L3CC were good on the flight, but RSO didn't think the rocket had enough initial thrust for the conditions. I showed up at the RSO with all paperwork and wind sims in hand for just this reason.