Fatty Finn - Fanga’s L3 design and build

[kjhambrick]

Thats almost it. I need to assemble the motor, which I will do on Friday night. Just paperwork now and the anxiety of waiting for the launch Saturday morning. Aggghhh. It's almost here.

EDIT: Clarifying that I will be assembling the motor in the presence of my TAP.

Awesome Rocket and Motor, @fanga !

Good luck with your flight !

-- kjh

 

[Theory]

very nice build!

 

[OzHybrid]

Congratulations on your successful flight yesterday. Great flight. Welcome to L3.
View attachment VID_20230930_095254Converted.mp4

 

[kjhambrick]

Congratulations @fanga !

Beautiful rocket and a very nice flight and recovery.

EDIT: I thought I asked but I posted from my phone:

How high and how fast did she go ?

Thanks !

-- kjh

 

[Jeremy Sim]

Well done Mate!!!

 

[rocketgeek101]

Congrats!!

 

[fanga]

Congratulations on your successful flight yesterday. Great flight. Welcome to L3.
View attachment 607300

Thanks Norm

I'm finally home and recovered. Great to be int he L3 club with you all. Looking forward to building some fun rockets next year.

 

[fanga]

Congratulations @fanga !

Beautiful rocket and a very nice flight and recovery.

EDIT: I thought I asked but I posted from my phone:

How high and how fast did she go ?

Thanks !

-- kjh

Thanks heaps. She got to 4562ft according to the RRC3 beeps when I went to recover her. I'll download the data from the Raven later today and get some more info for ya.

 

[fanga]

Heres a video taken by a kind Uni student with a big lens on his camera. You can see the apogee event.

 

[fanga]

OK Data has been retrieved from Raven.

Max Altitude: 4,520ft
Max Velocity: 82.6 ft/s

This has to be wrong. I'm trying to figure out. Also the roll looks amazing if the app is telling me the right thing. I'll confirm this before posting.

Does anyone know how to read the velocity of the data files? Im out of time today but I will share the data files here if anyone feels the need to take a look I will have a look at the weekend.

 

[RocketRev]

I'd like to hear exactly what you want to see in the original proposal . I assume an OR drawing, all the materials you want to use throughout the rocket, and why you chose this model?

This threads been going for a while, but I just noticed that Hobie1dog might be asking me what I'm looking for in an L-3 proposal package. If he wasn't asking, well...you could skip this response. It's just my usual long winded reply.

Well I must admit that I do have one hobby horse that I tend to ride a lot when it comes to designs: "SPACE............The Final Frontier..........These are the Voyages of......" Hey stop that music! Turn the lights back on..... Uh sorry about that. Long time Trekie here. It just sort of came over me.........

By SPACE, I am not referring to where many of us have been dreaming we'd love to go to, as in "outer space." I am referring to the amount of space that's designed into the L-3 cert rocket specifically for the recovery system. I've had dozens of L-3 certs that had troubles because the design did not have enough open space to comfortably hold and deploy a recovery system. "But the parachute fit when I tested it!" I've heard many times. But they forgot that there's a whole lot more to a recovery harness than just the parachute. And don't for get those pesky "eye" and "U" bolts that can stick into the parachute bay, and ejection charges, and flame retardant bags/sheets/sleeves/etcetera, wadding, and so many things. Everything that's as part of the recovery harness needs to be included in the design, and obviously enough space to pack it.

I can't tell you how many times I've had fliers show up at the launch only to realize that their design only left them 6 inches of open area in a 6 inch diameter tube for a 12 foot parachute and 75 feet of recovery harness. I have seen failures to deploy a recovery system because it was packed in so tightly that with the rocket laying on the ground in pieces, but the parachute could still not be pulled from the airframe. That one had been "packed" with a hammer.

And don't forget the fairly normal (here in the Mid West anyway) dual deploy system with the need for enough volume for a drogue chute with its harness. And most of the time this is a separate space from the main chute.

Designing enough volume for a full Recovery System is my main bugaboo. Its much much better to have a few inches of space to spare than to need a few more inches of space that you simply do not have available.

The only other bugaboo that get's me is the TAP or L3CC who doesn't show up at the launch for the certification flight and the flier suddenly finds themselves searching desperately for an available TAP or L3CC to fill in at the last minute. And then I have to guess as to the quality of the fliers building techniques because much can be hidden by paint and epoxy. I don't mind too much, but it seems to happen a lot. But this is rarely the fliers fault. Its just hard to oversee a project that I can no longer really dig into including the design phase which at that point I'm way too late to get into.

Well, that's my 2 cents worth.

Brad

PS: anybody besides me remember back when type-writers had a "cents" sign {a small c with the vertical line thru it} right along with the dollar $ sign?

 

[kjhambrick]

OK Data has been retrieved from Raven.

Max Altitude: 4,520ft
Max Velocity: 82.6 ft/s

This has to be wrong. I'm trying to figure out. Also the roll looks amazing if the app is telling me the right thing. I'll confirm this before posting.

Does anyone know how to read the velocity of the data files? Im out of time today but I will share the data files here if anyone feels the need to take a look I will have a look at the weekend.

@fanga --

Thanks for posting your raw BlueRaven.csv files !

I thought I sent this a few weeks ago,

Sorry !

I wrote a q&d gawk script that plucks interesting fields from the low_rate file.

These are the highlights.

Liftoff detected at 'file time' = 2.041 sec
Max Pressure Altitude was 4,519 ft at file time 19.721 sec ( note the 'E' Event )
Max Axial Velocity (up) was 564 ft/sec at file time 4.761 sec

Note that the file time is stored in col[ A ]

Flight Time is in col[ I ]

If you give me the site temperature, the script ( avs.sh ) will convert pressure altitude ( palt ) to density altitude ( dalt ) which will be a little different if the site temperature was not 60F.

HTH and Congratulations again !

-- kjh

p.s. If you want the set of Blue Raven scripts I have so far, I would be happy to share them.

You need linux or another shell environment with bash, gawk, sed, etc ...

EDIT: p.p.s. Yes, your Roll Angle DOES look amazing -- good job on your fins @fanga !

 

[cwbullet]

Congrats on the successful level 3. You might want to padlock the wallet.

 

[fanga]

Congrats on the successful level 3. You might want to padlock the wallet.

Hahahaha

Yep The dollar figure in my planning spreadsheet for next years flights has got me worried

 

[fanga]

@fanga --

Thanks for posting your raw BlueRaven.csv files !

I thought I sent this a few weeks ago,

Sorry !

I wrote a q&d gawk script that plucks interesting fields from the low_rate file.

These are the highlights.

Liftoff detected at 'file time' = 2.041 sec
Max Pressure Altitude was 4,519 ft at file time 19.721 sec ( note the 'E' Event )
Max Axial Velocity (up) was 564 ft/sec at file time 4.761 sec

Note that the file time is stored in col[ A ]

Flight Time is in col[ I ]

If you give me the site temperature, the script ( avs.sh ) will convert pressure altitude ( palt ) to density altitude ( dalt ) which will be a little different if the site temperature was not 60F.

HTH and Congratulations again !

-- kjh

p.s. If you want the set of Blue Raven scripts I have so far, I would be happy to share them.

You need linux or another shell environment with bash, gawk, sed, etc ...

EDIT: p.p.s. Yes, your Roll Angle DOES look amazing -- good job on your fins @fanga !

Mate this is awesome. Thank you sooo much. I would love to have a look at your gawk scripts. I will reach out in a couple of weeks. Getting smashed by other things right now.