Deep Space Offl (was: My L1 build has an OFFL finish...)

I'm officially trying to build my L1 rocket. It's a scratchbuild, It's themed (Mark, no giving them any more clues), and in some points, I'm still clueless.

I'm opting to do a 3FNC.

The Nosecone is a custom job, If I could only hear back from the person who offered the best option again (3D printing). Despite what the image below appears to show (a rounded front surface), it's actually flat. When I get done, the reason for that will be made apparent.



Overall length will be about 25.25".
Body will be a 4" diameter, I'm going with what Mike Fisher (Binder Design) can supply me with.
MM is from Sunward (their 38mm mount for 3.9" ID body tubes).
Fins are 1/8" thick birch ply.

What I don't know is: How large of a 'chute I need. Where to score a motor retainer, and where I should go for Launch buttons. Input on these features will be greatly appreciated.

Wrap will be custom from Stickershock.

Stay Tuned...
Jim

K'Tesh said:

What I don't know is: How large of a 'chute I need. Where to score a motor retainer, and where I should go for Launch buttons. Input on these features will be greatly appreciated.

Click to expand...

I address all these topics in my Certify Level 1 video.

Best of luck on your build and cert attempt. The chute size... build it. Paint it. Weigh it. Then determine what you'll need to bring it down safely.


Later!

--Coop

the size of your chute depends wholly on the weight of your rocket, and since you are completely scratch building it I would assume you don't know yet. But here is a nice write up of the calculations involved in determining the size of your parachute:
https://www.apogeerockets.com/downloads/Newsletter149.pdf

the other option is to "try out" different sizes in open rocket, just make sure to keep the landing speed under around 15 ft/s.

for motor retention there are lots of methods. you can go cheap and get a sheet metal retainer, or you can go fancy and get an aeropack screw on retainer.

Hope this helps

K'Tesh said:

Where to score a motor retainer, and where I should go for Launch buttons. Input on these features will be greatly appreciated.



Stay Tuned...
Jim

Click to expand...

Subscribed.... and Good Luck

Look here Jim for that stuff.

www.railbuttons.com

www.giantleaprocketry.com

Looks good something you can cert on 38mm and still fly on 29mm but I would op for the 54mm and adapt down just my two cents .

Best of luck!

Watching...

chris m said:

Looks good something you can cert on 38mm and still fly on 29mm but I would op for the 54mm and adapt down just my two cents .

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Why can't he cert L1 with 29mm? I'm planning on doing so next month with a 29mm rocket so hope I'm not missing something and just mis reading your statement.

You can cert L1 with any casing size you choose as long as the commercial motor is a H or I impulse. Having said that, you have a much large selection in 38 mm than in 29mm or 54 mm.

Bob

This should be interesting!

Is it really going to be only 25" long? That's pretty short for a 4" diameter rocket, isn't it? And a custom NC with a flat front... I'm looking forward to seeing the whole design.

bobkrech said:

You can cert L1 with any casing size you choose as long as the commercial motor is a H or I impulse. Having said that, you have a much large selection in 38 mm than in 29mm or 54 mm.

Bob

Click to expand...

Wheew... Thanks Bob.. that confirms what I thought originally. I plan to use in Aerotech an H128 or H135 or in CTI an H135 or H118

Ed

https://rail-buttons.com/

This is all you need :wink:


Good luck with the build!


Braden

Camroc?

ThirstyBarbarian said:

This should be interesting!

Is it really going to be only 25" long? That's pretty short for a 4" diameter rocket, isn't it? And a custom NC with a flat front... I'm looking forward to seeing the whole design.

Click to expand...

No Thirsty, it'll be longer than that (by about .23"). The original version of this was 19.9" long in the 4" diameter config. I contemplated a 6" diameter version, but that was going to be only ~29.75" long. Seeing how much my first "bid" on the nosecone was, I decided to stick w/4" for economic reasons, and stretched the rocket by 5" to give me a little bit more room to play with.

Txnrcr said:

Camroc?

Click to expand...

As much as I'm into rocket photography/filmography I can understand the guess.

Nope. Not a Camroc.

If you are getting your body tube from Binder, he also sells a very easy/inexpensive motor retention system and rail buttons.
Check them out: https://binderdesign.com/store/page6.html

chuck5395 said:

If you are getting your body tube from Binder, he also sells a very easy/inexpensive motor retention system and rail buttons.
Check them out: https://binderdesign.com/store/page6.html

Click to expand...

Now I know why I ask these questions... There's a lot of very smart people who have been here long enough to remember things like that. Thanks!

It's about time, I'd say.

When do you plan to fly?

Good luck on your build and flight!

The reason why I suggested 54mm or even 75mm is its cheaper to build bigger than to build another one with a bigger hole . You can always go down a size up not up . I would SIM different motor sizes to see if that 54mm 4 grain k would fit and still be stable .

See...I thought I misread it...going bigger makes sense as you can always put a smaller adapter in but to go bigger You would have to build another rocket.
Not that any of us would want to go bigger..Ha, Ha.

Bigger is better . Wish I listen when I built my L2 rocket think it would do well on a k or L

No reason to build a level 3 rocket for a level one certification. You're on the right track, stay the course.

As I'm planning on doing a Binder Design Velociraptor for my L2, I'll stick with the 38mm motor. As it has already been pointed out, this is really a short rocket for a 4" diameter build. Just to get the CG/CP to 1.3 cals, I've had to sim this with 14.5oz of weight in the nose. Is launching a can of soda (as a payload)(I don't drink beer (more for you)) out of the question? I'd hate to see it spray all over the place, but it makes the finding a suitable weight a lot easier. BTW, the nose shape has now been given a 4" shoulder, based on input from Mike Fisher.

Besides, I doubt that I'll be able to score my L3 before I take off for Asia, and I've yet to determine what (if any) chance I'll be able to buy, build, or fly in China or Taiwan.

K'Tesh said:

As I'm planning on doing a Binder Design Velociraptor for my L2, I'll stick with the 38mm motor. As it has already been pointed out, this is really a short rocket for a 4" diameter build. Just to get the CG/CP to 1.3 cals, I've had to sim this with 14.5oz of weight in the nose. Is launching a can of soda (as a payload)(I don't drink beer (more for you)) out of the question? I'd hate to see it spray all over the place, but it makes the finding a suitable weight a lot easier. BTW, the nose shape has now been given a 4" shoulder, based on input from Mike Fisher.

Besides, I doubt that I'll be able to score my L3 before I take off for Asia, and I've yet to determine what (if any) chance I'll be able to buy, build, or fly in China or Taiwan.

Click to expand...

Gene from Fruity Chutes always holds a beverage can lofting challenge at NXRS each year! Absolutely that would work...

When do you think you'll do the L1 cert?

AlnessW said:

Gene from Fruity Chutes always holds a beverage can lofting challenge at NXRS each year! Absolutely that would work...

When do you think you'll do the L1 cert?

Click to expand...

Nottaclue...

K'Tesh said:

As I'm planning on doing a Binder Design Velociraptor for my L2, I'll stick with the 38mm motor. As it has already been pointed out, this is really a short rocket for a 4" diameter build. Just to get the CG/CP to 1.3 cals, I've had to sim this with 14.5oz of weight in the nose. Is launching a can of soda (as a payload)(I don't drink beer (more for you)) out of the question? I'd hate to see it spray all over the place, but it makes the finding a suitable weight a lot easier. BTW, the nose shape has now been given a 4" shoulder, based on input from Mike Fisher.

Besides, I doubt that I'll be able to score my L3 before I take off for Asia, and I've yet to determine what (if any) chance I'll be able to buy, build, or fly in China or Taiwan.

Click to expand...

Is this why the top of the NC is flat? You're going to balance a can of soda on top?

ThirstyBarbarian said:

Is this why the top of the NC is flat? You're going to balance a can of soda on top?

Click to expand...

LOL! No.

When it's finished you'll understand. Suffice it to say, I'm trying my hand at an INSTANT CLASSIC design.

Small caveat... I've already received the first invoice from Stickershock, and it said

Just need to sign over your firstborn!

Click to expand...

Now, All I need is someone to help me obtain a firstborn... Unless he's talking about pet mice, and then he's about 20 years too late for that (or 30 years late for pet rats).

True Story. Until this build, I've never seen a 2nd email started as the first email's replies were so large that the server couldn't handle them. Mark and I have managed to do that, but I doubt that can happen again, as the wrap is nearly finalized.

K'Tesh said:

LOL! No.

When it's finished you'll understand. Suffice it to say, I'm trying my hand at an INSTANT CLASSIC design.

Small caveat... I've already received the first invoice from Stickershock, and it said


Now, All I need is someone to help me obtain a firstborn... Unless he's talking about pet mice, and then he's about 20 years too late for that (or 30 years late for pet rats).

True Story. Until this build, I've never seen a 2nd email started as the first email's replies were so large that the server couldn't handle them. Mark and I have managed to do that, but I doubt that can happen again, as the wrap is nearly finalized.

Click to expand...

Ha ha!

The mystery deepens. I can't wait to see the final result!

chris m said:

The reason why I suggested 54mm or even 75mm is its cheaper to build bigger than to build another one with a bigger hole . You can always go down a size up not up . I would SIM different motor sizes to see if that 54mm 4 grain k would fit and still be stable .

Click to expand...

"First rule in government spending... Why build one when you can have two at twice the price?"

[video=youtube;Et4sMJP9FmM]https://www.youtube.com/watch?v=Et4sMJP9FmM[/video]

Besides... I already have the 38mm motor mount, and I've cut it down (from 20") so there's no taking it back. I chose 38mm based on the recommendations I found on Apogee's L1 certification video. I've built 29mm rockets that are completely capable of certification on. However, they are 2", 2.5", 2.6", and 3" based rockets, all are sleek, and I'd really like to get them back, intact.

This one sims out at at 1180' to 1330' on an Aerotech H73J-6 Reloadable motor. My best (slowest) recovery has it landing at 16.1fps using a PML-PAR-44R (44" parachute).

Now for the first time... I'll post the .ork file , and an image of what it sims out to be, less one critical deca... er... detail.



View attachment Classified L1 Certification build.ork