Help me decide on my L2 rocket...

[Rocketjunkie]

In the late 80's I witnessed a LOC/Precison Motherlode fly at LDRS on a cluster of three Vulcan L750's. I've been a believer in the strength of cardboard rockets ever since .....

I was there for that flight. Good up part, not so good recovery. Everyone was still using elastic back then...

 

[Jon Craig]

I think you had it right with the Goblin,


The 3" Goblin can launch on as low as an F and one of the fastest things I ever saw was a launch my son did with a J500. A J350 would be perfect for a level 2 Likewise the 4" lets you do a bunch of different motors, fun on an I, cert on a J, really fun on a K. Either the 3" or 4" works for a level 2.

One other plus is the length, easy to store and bring out. If you use it for your level 2, it certainly will compliment 'your next rocket'.

I wasn't even thinking of going as small as the 4" - I was thinking 5.5"! 54mm mount is nice.

 

[kramer714]

The 4" has a 54mm mount. It comes pre-glassed and slotted.

 

[sailmike]

I used the Polecat 5.5" Fat Man for my level 2 cert. After the flight an ebay was added, which Jack sells for about $50. I think it went to about 2,000' on a J350.
Very very easy to assemble.

Mike

 

[Jon Craig]

I used the Polecat 5.5" Fat Man for my level 2 cert. After the flight an ebay was added, which Jack sells for about $50. I think it went to about 2,000' on a J350.
Very very easy to assemble.

Mike

Hmm interesting. I wonder if you could use one on a Gobby?

 

[Jon Craig]

And why 4" over 5.5"? Just like 'em smaller?

 

[kramer714]

4" or 5.5, either would be good. My level 1 and 2 (same rocket) rocket was a scratch built 4", pretty basic other than being zipper-less design.

Funny thing, This is the rocket that gets flown most. I still enjoy launching some of my more complex and larger rockets, my biggest to date is a 16 foot tall 8" diameter M-hybrid.

I can take this rocket, and in 10 minutes and less than $20 (h128) get a fun flight even if there is a bit of wind. It is a no brainer to prep and in well over 30 launches only had a problem once. Still uses the same chute and shock cord as I used on my level 1. Or same 10 minutes load it with a J350 (or bigger) and get some serious altitude. Usually the 'big project' gets launched in the morning after being prepped at home before going out, and the Goblin or my Level 1-2 rocket gets launched a bunch in the afternoon.

 

[Jon Craig]

Ok - well - awesome recommendations and discussions here.

Basically we've got G3/Mad Dog, Hyperloc 835, Goblins, or the Binder Excel... mostly.

Goblin's not DD - the rest are. Out of those, which are designed to be (or easily modifiable to be) "convertible" between single D/motor ejection and DD "at will"?

 

[Dlee]

There are a lot of options, I have built Binder designs rockets and I agree they are top quality parts, and the best in instructions.

I am working on my own L2 project now, an Always Ready Rocketry Blue Phoenix 4.

I wanted something beefy, without fiberglass.

 

[Jon Craig]

Always Ready Rocketry Blue Phoenix 4.

WHOA, that's a cool looking kit! Very cool fins.

 

[talkin Monkey]

How about one of LOC Bruiser variants?

 

[Jon Craig]

Ok - well - awesome recommendations and discussions here.

Basically we've got G3/Mad Dog, Hyperloc 835, Goblins, or the Binder Excel... mostly.

Goblin's not DD - the rest are. Out of those, which are designed to be (or easily modifiable to be) "convertible" between single D/motor ejection and DD "at will"?

This is the question I'm still needing to resolve.

 

[WillMarchant]

If the rocket comes with an avionics bay then you're golden. If it doesn't then things are a bit more complex. Too complex for a L2 attempt? That is up to the individual flyer and their mentor(s) to discuss.

Probably, the most conventional way to make a single deploy rocket DD is to put an accelerometer based altimeter into the nosecone and then use some sort of chute reefing system (Defy Gravity Tether or other parachute "burrito") for the mains. I suspect you could also put the mains into a tube attached to the recovery harness that would come out at apogee but hold the parachute until the desired mains ejection altitude.

 

[Dlee]

I have some pictures of the excruciatingly slow build ( it is a project I am working on a couple of hours each weekend with my elderly father )

We are making lots of minor modifications, it will be a dual altimeter rocket with an LCX and an RRC2 as backup. I am going with a Giant Leap plastic nose cone as I had some problems with the fiberglass nosecone.

Im going overboard on stuff ( I usually do ) 2, 4" fireballs, using 1/2" tubular Kevlar as shock cord etc etc etc

Here are some pics of the early parts of the build, I will be adding more in the next week or so.

This will be my first dual deploy rocket called… drum roll….. “Second Chance” for a number of reasons, but one is that I am making it as redundant as I possibly can.


https://dwightandhelene.smugmug.com/Other/Level-2-project/8891932_6Dd2R#589739883_XkhM3

WHOA, that's a cool looking kit! Very cool fins.

 

[Jon Craig]

Well - I went ahead and made a decision...

1 $119.00 Performance Rocketry - Econoline Series - G3 - 3" G3 - F/Glass$119.00
1 $89.99 Electronics - MissileWorks - rrc 2 mini - RRC2 Mini Altimeter$89.99
1 $27.50 Aerotech - 38mm High Power Reload Kits - 08242M - H242T-M$27.50
1 $27.50 Aerotech - 38mm High Power Reload Kits - 08073M - H73J-M$27.50
1 $29.59 Aerotech - 24mm Reload Kits - 63906 - F39-6T (3PK)$29.59
1 $7.25 Top Flight - Standard - PAR18 - PAR-18" $7.25
1 $26.95 Top Flight - Standard - PAR58 - PAR-58" $26.95
1 $44.00 Retainers / Adapters - Aeropack - TRA5430PB - 54mm - 3"
Tailcone Assembly - PML, Black$44.00

Ordered.

 

[Dlee]

Good for you Jon

Are you going to have a place where we can see occasional pictures of the build? I am in the same place as you are ( working on my L2 rocket ) and would love to see what you do!

I really liked the RRC2, Im using that as my second altimeter.

My L1 was a scratch built thing loosely based on the BSD Horizon, very large 4" diameter and just over 6' tall, but I used a sub standard recovery harness and although It got me my L1 easily, after the 5th flight, the strap had fried and broke ( in 2 places ) and the rocket came down in 3 pieces, well 2 came down, the parachute was by itself and may still be floating out there somewhere.

The booster came in ballistic ( it was a zipperless design with a baffle ) and hit a parked truck ( ouch ).

Hence my going overboard on everything... very heavy harness, dual altimeters, everything I can think of to keep that kind of failure from happening again... and hence the name... Second Chance.

Looking forward to seeing your build, you may do stuff I can learn from.

 

[Jon Craig]

I do usually document/talk about my builds at my personal blog: https://www.sentence-ov-desire.net/

 

[kramer714]

Jon,

sounds like a good plan!

I did find a mistake that you made, not un common when you go to higher cert levels but a pretty big mistake none the less....

NEVER total up all of the cost of a build on one piece of paper, spread it around, delude yourself that it is only a couple of bucks here and there. Having it all listed on one sheet can cause a case of fundus interuptus.

Just trying to help you out...

Good luck with Level 2

 

[Jon Craig]

Jon,


I did find a mistake that you made, not un common when you go to higher cert levels but a pretty big mistake none the less....

NEVER total up all of the cost of a build on one piece of paper, spread it around, delude yourself that it is only a couple of bucks here and there. Having it all listed on one sheet can cause a case of fundus interuptus.

LOL!

The funds for this is the partial proceeds from selling out of another hobby, so.... no big deal.

 

[Bill P]

Well - I went ahead and made a decision...

1 $119.00 Performance Rocketry - Econoline Series - G3 - 3" G3 - F/Glass$119.00
1 $89.99 Electronics - MissileWorks - rrc 2 mini - RRC2 Mini Altimeter$89.99
1 $27.50 Aerotech - 38mm High Power Reload Kits - 08242M - H242T-M$27.50
1 $27.50 Aerotech - 38mm High Power Reload Kits - 08073M - H73J-M$27.50
1 $29.59 Aerotech - 24mm Reload Kits - 63906 - F39-6T (3PK)$29.59
1 $7.25 Top Flight - Standard - PAR18 - PAR-18" $7.25
1 $26.95 Top Flight - Standard - PAR58 - PAR-58" $26.95
1 $44.00 Retainers / Adapters - Aeropack - TRA5430PB - 54mm - 3"
Tailcone Assembly - PML, Black$44.00

Ordered.

Excellent rocket. Mine has a lot of flights on it, the nose cone has a nice rattle to it with all the shear pins (a nice sound).

The G3 will take a lot of "abuse". Mine has come down flat through trees with just scratches.

Your choice in parachute may be a bit much for this rocket. Unfortunately, the G3 has very little room in the payload bay. I use a 45" Anchor Parachute which really needs to be packed tightly and crammed into the little space that exists and shear pins are needed just to hold the nose cone from being pushed out by the parachute. The rate of decent most likely could be increased a lot more than I'm getting, I've cinched the 'chute the last few flights and think I could a lot more. I will be ordering a smaller parachute for my rocket, I don't know why I haven't yet. Laziness, I guess.

I haven't flown it on anything smaller than an I-motor, getting in the area of 1,500 feet. I had planned on flying an L in it a couple of months ago but the weather was terrible... maybe in November, but most likely will be sticking with a Loki 250. I think the F39 you ordered is for another rocket.

I think you will really enjoy it, besides stuffing the main in the tube.

 

[Jon Craig]

The F's are for my Pem-Tech SGM and Estes Big Daddy, yeah.

As far as 'chutes, oh well, I can always get a smaller one - they're cheap.

 

[Pantherjon]

Nice rocket choice..Presume the 38mm's are for test flights? What 54mm motor do you plan to use for your cert flight?

 

[Bill P]

I recommend a Loki K250 for the cert flight. Yup.

 

[Jon Craig]

Nice rocket choice..Presume the 38mm's are for test flights? What 54mm motor do you plan to use for your cert flight?

The 38s are for my Callisto. I just cut-n-pasted the entire order I placed, hehe.

As far as the 54mm motor - haven't decided yet. I'll see what cases our Prefect has to loan and pick something cool that fits.