Blue Lightning, My Path to L3

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dgreger

dgreger

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IMG_2113.JPG SC Precision Thrust Plate w/Aeropack 98mm Flanged Retainer.
IMG_2112.JPG One piece Stepped Bulkheads and 98-75MM Aeropack adapter
IMG_2114.JPG60" Booster, 36" Payload bay, 5-1 Von Karman NC, 36" 98mm Motor tube
It will be a simple 3FNC design, 6" diameter, 11ft tall. Will probably Cert on the 75mm CTI M1101, so far estimates are around 6kft.
What is not shown that I already have is the av-bay sled already done, using the tried and tested sled from my Upscale Archer, Medium charge wells from Blast Cap, waiting on CRs, coupler, 2" switch band and NC bulkhead. Still Havent finalized fin design, but probably going split fins, have a few different designs just have to decide which I will use. Won't order recovery laundry and cords until built and weighed but will probably need the Sky Angle Cert L3 XL for the main.
 
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I never used an emoticon ever never ever .....

:pop::pop::pop::pop::pop:

:wave::wave::wave::wave:

lol...

Teddy
 
Name of the rocket has been chosen, Fin Design finalized, and Paint job decided.

Here's a rendering, although doesn't show what the real paint job will look like, gives you an idea of fins and basic color:

RTL Rendering.jpg
 
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Hey, Dave, I'm in Columbia, too, so if you need any help or moral support, let me know.
 
dgreger said:
View attachment 270632 SC Precision Thrust Plate w/Aeropack 98mm Flanged Retainer.
View attachment 270633 One piece Stepped Bulkheads and 98-75MM Aeropack adapter
View attachment 27063460" Booster, 36" Payload bay, 5-1 Von Karman NC, 36" 98mm Motor tube
It will be a simple 3FNC design, 6" diameter, 11ft tall. Will probably Cert on the 75mm CTI M1101, so far estimates are around 6kft.
What is not shown that I already have is the av-bay sled already done, using the tried and tested sled from my Upscale Archer, Medium charge wells from Blast Cap, waiting on CRs, coupler, 2" switch band and NC bulkhead. Still Havent finalized fin design, but probably going split fins, have a few different designs just have to decide which I will use. Won't order recovery laundry and cords until built and weighed but will probably need the Sky Angle Cert L3 XL for the main.
Click to expand...

Sounds like a great rocket. My L3 was Kenny Allen's Performer 150 and the only significant difference seems to be the payload tube. Mine came with 48" vs. the 36" you are using.

I found that the 48" disappeared pretty fast. I lost 6" to the nose cone and 9" to the av-bay. My av-bay was 16" long and I put most of it in the payload to make sure the 60" booster could hold the Pro98 6GXL case. Between my homemade chute that doesn't pack near as tight as some of the commercial ones and a pilot chute for the nosecone and d-bag, it turned into a surprisingly tight fit in the payload.

My suggestion would be to look into the main chute and recovery system early in the build and make sure it will fit the 24" of space I assume you will have left in the payload. I know 24" x 6" sounds big, but as I got into my L3, I was a little surprised at how fast that room can disappear when you increase your chute sizes from 15 - 25 lb L2 birds to what's needed for +50 lb L3.

I'm assuming a cert flight at MDRA, but if you get a chance, come down and fly at BattlePark some day.

Good Luck!!!
 
Handeman said:
Sounds like a great rocket. My L3 was Kenny Allen's Performer 150 and the only significant difference seems to be the payload tube. Mine came with 48" vs. the 36" you are using.

I found that the 48" disappeared pretty fast. I lost 6" to the nose cone and 9" to the av-bay. My av-bay was 16" long and I put most of it in the payload to make sure the 60" booster could hold the Pro98 6GXL case. Between my homemade chute that doesn't pack near as tight as some of the commercial ones and a pilot chute for the nosecone and d-bag, it turned into a surprisingly tight fit in the payload.

My suggestion would be to look into the main chute and recovery system early in the build and make sure it will fit the 24" of space I assume you will have left in the payload. I know 24" x 6" sounds big, but as I got into my L3, I was a little surprised at how fast that room can disappear when you increase your chute sizes from 15 - 25 lb L2 birds to what's needed for +50 lb L3.

I'm assuming a cert flight at MDRA, but if you get a chance, come down and fly at BattlePark some day.

Good Luck!!!
Click to expand...

+1.......

Check----

Your intended finished weight...
What size and type of chute and harnesses and blanket you'd like to use...
That you can pack everything in the intended payload compartment before you start the build...

If you find out you're a bit tight at this point at least you have good options,, like getting a longer payload tube...
If you find out when you're done with the build and start the recovery set up your options will be greatly limited ....

This is for your level 3 ....
You will remember this build and flight forever....
Don't rush ,, take your time,, check things before any epoxy is mixed David...

Teddy
 
Handeman, yes, I've given all that alot of thought, As I have already pretty much figured on the Skyangle XL due to the expected weight range, I can save space by using a d-bag, and no separate chute for the nose. and if I run out of room up top I can move the bulkplate in the NC up inside, being a 5:1 theres lots of volume in there to use.
And Teddy makes awesome super strong lightweight easy to pack kevlar harnesses.
The booster section pretty much is not going to change so I can build that, the one thing I cannot decide on is whether or not to build the fincan/MMT and slide it into the airframe or just slot the tube and mount the fins then do internal fillets. Both have their advantages/disadvantages.
Definitely looking at Spring Red Glare at the earliest for the Cert Flight. Needs to be at Higgs Farm due to expected altitude.
 
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Absolutely David,,,
My last build I had a hard time deciding whether
to mount the fins to the motor tube then slid it in
or to put the fins through the slots and inject...

You're 100% right...
There's good and bad to both methods...

Teddy
 
I put the MMT in mine and glued the fins in, then pulled the aft CR back out and filleted the inside. It's a little difficult to get in there with the 6" BT and 98mm MMT. I was using fiber mixed into the epoxy so it was even messier. I would recommend the method you are most experienced and most comfortable with.
 
As I am in no hurry the build is slow going, however I was able to finalize the fin design:
One Fin.png

I was also able to (with the help of G-Dog) get the three threaded rods added to the sim file.
Tapped the three holes in the thrustplate for the threaded rods.
Cut a couple 1/4" plywood CRs, one of which will be mated to the thrustplate. And started on the sled for the electronics bay.
CRs, Coupler, one more bulk plate and switch band should be ready for pickup at ESL-208 Oct 10-11 from AMW.
I had AMW order a custom length coupler, 14" long vs the standard 12" so I could use a 2" switch band.
Also decided to cut the MMT down to 30" vs 36"

Meanwhile, yesterday I cut the fins for my USMC project
Here's the shape:
USMC-Fin.png

I want to bevel the fins all the way around and have access to routers (freehand and table mounted) What have you guys found is the best way to do that?
I would really rather not do it by hand.......lol

Also cut the fin slots for them, and drilled the aft CR for the 54mm flanged retainer.
More to come on this one later.
 
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Yeah Dave,,
+1 on the fin shapes,,
Both of them...

Also shortening the motor mount...
This will give you more room in the booster for no cost....

Teddy
 
ImageUploadedByRocketry Forum1445856078.616053.jpg
Holes drilled and U-bolts test fitted on upper CR, also laid out and drilled all the holes in the bulkheads for the E-bay for terminals, charge canisters, and U-bolts.
Also separated the coupler from the nose cone. It was pretty well stuck, took the aluminum tip off and used a piece of 1/2" wooden dowel and lightly tapped the upper edge of the coupler from the top evenly around and it finally started to come out.
ImageUploadedByRocketry Forum1445856289.340597.jpg

What I would like to do is instead of the traditional method of epoxying the bulkhead to the bottom of the coupler, then the coupler into the NC is put the bulkhead on the top of the coupler, and use 6 or 8 threaded inserts and machine screws to attach the coupler to the NC. That would give me 6 more inches of room for the main recover gear if I need it, and I might. I want to use deployment bag with a small drogue to pull the main. Thoughts?

Oh and it now has a name!
 
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I understand putting the bulkhead at the top end of the coupler to make more payload space but then why not just epoxy the coupler into the nosecone?
 
Nathan said:
I understand putting the bulkhead at the top end of the coupler to make more payload space but then why not just epoxy the coupler into the nosecone?
Click to expand...

I kind of like the idea that I can remove it if I ever have to. Not that I envision ever having to, but nice to know I can?
 
Then make sure those machine screws aren't too long. Wouldn't want any recovery gear getting hung up on the pointy end of a screw.
 
Nathan said:
Then make sure those machine screws aren't too long. Wouldn't want any recovery gear getting hung up on the pointy end of a screw.
Click to expand...

Nope, basically going to use the same technique as standard rail buttons:
railbuttons.jpg

Drill the holes, epoxy the backing inside the coupler and cut off smooth, then countersink the screw head into the outside of the NC.
 
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Here's a quick OR picture, while not completely finished gives another idea of what its going to look like.

Open Rocket Drawing.jpg
 
Looks good so far. I like the M1101, relatively gentle introduction to big motors, pretty flame to boot -
B-Rrzkkkp0TD4_f0FbKuFI5k78XM4KgYdaZ1rAJn9A-qholrW6b6oW9kJkQzmu9VMpUKDw
 
well, if the weight keeps going up and I can squeeze a few more pounds into her (which will probably happen once I get it all buttoned up, weighed, and painted)
I'll probably go ahead and fly a 98mm, M1520 Blue Streak at a current est of 8400ft.
 

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