Little Joe

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Greetings everyone, This is my first post and I am new to the site. I have the skills and have built model rockets in the past.
I want to build a little Joe model rocket similar to the size Sheri's Rockets used to sell. The scale would be around 1/30 scale or so, I have not decided.
I'm thinking the diameter would be around 5". I only want the rocket to fly 250-300 feet. I'm thinking one D-3 engine. Your thoughts?

Iv been searching for 5" tubes on the net, not much around. I also was looking here https://www.rocketreviews.com/unknown-shr-ljii.html
If you notice on the page there is a link for rocksim and the planes for Sheri's rocket little Joe. Do you know if I can actually build the little Joe and then see how it would fly with my specs?

I would appreciate any links or contact info and especially how you feel about the size I'm interested in building and flying it and the altitude I mention above.
I live in a rural area and this project wouldn't be used in any competition's. A friend and I fly these in a farmers field. So I hope you will respond and help me with this project.
Thank you,
Gary
 
5in diameter and a single low-average-impulse-D don't mix.

My suggestion would be to try out something like the Mercury / BMS Big School Rocket to get a feel for lightweight construction and flight.

That should give you experience enough to start deciding the particulars of your desired scratch build.

Just my opinion though. Welcome aboard!
 
e30 & g74 are certainly have a lot more snort than a d3. I'll definitely reiterate my previous advice to pick a nice, light, wide kit and see if you can keep it under 300ft.

For instance, a build that would go 250ft on an e30 might easily go 1,000ft if it held together on a g74.
 
So you are thinking if an Apollo Little Joe II, as opposed to a Mercury Little Joe.
Good choice, great subject.
As previously said by these guys...at 5 inch diameter I think you are well into a G motor range, if not more, - depending of course on your all up - ready to fly weight.

by comparison, I scratch built one (my profile page avataar) at 8.5 inch diameter...VERY VERY lightweight, it has always flown with an H, often with clustered D's.
Slow realistic liftoff, and several hundred feet.
First fight with a G barely got it to a recovery altitude, so various H's are my preference for it.
A 5 inch might work for you with a G...a single D or E sounds a little iffy.
 
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So you are thinking if an Apollo Little Joe II, as opposed to a Mercury Little Joe.
Good choice, great subject.
At 5 inch diameter I think you are well into a G motor range, if not more, - depending of course on your all up - ready to fly weight.

I scratch built one (my profile page avataar) at 8.5 inch diameter...VERY lightweight, it has always flown with an H, often with clustered D's.
Slow liftoff, and several hundred feet.
First fight with a G barely got it to a recovery altitude, so various H's are my preference for it.
A 5 inch might work for you with a G...a single D or E sounds a little iffy.
Would you be willing to share your build on the little Joe? Build thread?
 
5in diameter and a single low-average-impulse-D don't mix.

My suggestion would be to try out something like the Mercury / BMS Big School Rocket to get a feel for lightweight construction and flight.

That should give you experience enough to start deciding the particulars of your desired scratch build.

Just my opinion though. Welcome aboard!
Thanks dhbarr for the hospitality. A friend of mine built a Saturn from poster board at 5 or so inches and around 6 foot tall. Fly's great!
 
Sheri's LJ II used a 29mm Aerotech G. I don't think a D motor is feasible, even more so since the large diameter body tubes don't come in thin wall design. If you are cloning this I think a 29mm G is the smallest motor that's feasible for low apogee. Consider that the short, stubby LOC Minie Magg, at about the same diameter, needs a G motor at minimum to go a few hundred feet. Just my opinion.
If possible, try simming your design in Open Rocket or Rocsim to see what engine sizes will work. Safer than launch it and see.
 
Would you be willing to share your build on the little Joe? Build thread?

Build thread.....it was on this forum about ten years ago...I think you can cruise these archival pages, and get the gist of it, including the launch.
Some of the pictures are still there, some are accessible if you open them, some not.
Hand rolled body tube from poster board, foam core bulkheads, Loc P. parts for the internal structure.
The ribbed exterior airframe and escape tower were labor intensive....
Good luck...fun rocket to fly.
I've gotten a lot of mileage out of it..and on this Forum LOL.

Build thread - archive link:
https://www.rocketryforum.com/showthread.php?110950-Little-Big-Joe-II-Build&highlight=nike+hercules

LBJ%20-%20II%20-%20aft%20endA.JPG

Little Joe at VAST.jpg

Little Joe II LDRS 36 2017.jpg
 
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Wait, I'm confused...are we talking about a Little Joe (Mercury program), or a Little Joe II (Apollo program)?

I might be able to provide some guidance on either of these, but need to know which way the OP wishes to head...

James
 
Sheri's LJ II used a 29mm Aerotech G. I don't think a D motor is feasible, even more so since the large diameter body tubes don't come in thin wall design. If you are cloning this I think a 29mm G is the smallest motor that's feasible for low apogee. Consider that the short, stubby LOC Minie Magg, at about the same diameter, needs a G motor at minimum to go a few hundred feet. Just my opinion.
If possible, try simming your design in Open Rocket or Rocsim to see what engine sizes will work. Safer than launch it and see.

Wait, I'm confused...are we talking about a Little Joe (Mercury program), or a Little Joe II (Apollo program)?

I might be able to provide some guidance on either of these, but need to know which way the OP wishes to head...

James
Either one would be awesome. I would appreciate the insight.
 
Want to mention that I only want to use a single motor in this little Joe project. Again, I am only after 300 feet or so☺
 
Want to mention that I only want to use a single motor in this little Joe project. Again, I am only after 300 feet or so☺

A Little Joe or Little Joe II based on BT-101 tubing (~4" OD") would be a hoot, and either would fly well on a single E15-4 motor. A 4" Little Joe would be 1/20 scale, and a 4" LJII would be be about 1/38 scale.

Ideas for a scratch-built Little Joe can be gleaned from this thread:https://www.rocketryforum.com/showt...Joe-I-(was-Anyone-care-to-ID-this-component-)

Anyone hoping to scratch-build a Little Joe II should familiarize themselves with the excellent Estes kit: https://www.rocketryforum.com/showt...s-Little-Joe-II-Tips-Tricks-and-Modifications

James
 
Nice build there! Have any pics of the construction of the inside of tube?
 
I've you're looking at the Little Joe II for the Apollo, get all the info you can from MaxQ. I've seen his fly many times, some good and some not so good. Either way, he's the guy with the experience!
 
You can definitely do it with the right materials and construction, I've done a foam sheet centering ring/stringer/foam sheet skin constructed 5.5" pershing 1A about the same size as Max Q's Little Joe II, weighs about 20 oz rtf, have flown it on E-30's to around 300' and F-32's to round 400'. It has a lightweight 24mm core tube, expanding to a BT-70 parachute compartment, and uses a very lightweight 30" nylon parachute.
 
I've you're looking at the Little Joe II for the Apollo, get all the info you can from MaxQ. I've seen his fly many times, some good and some not so good. Either way, he's the guy with the experience!

Heheh...we all have our good and bad days....that's for sure. :blush:

Mine is still alive and ticking...but I think the fins have taken a beating to the point its time to go bigger.
Mine doesn't have the detail and craftsman ship as Mr. Duffy's projects, but it's still a fun funky flyer.
 
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