L2 Build Terminated

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
The Eagle Claw has some features that make it a little complex but not a bad build. if you do a search there are at least 2 build threads already here on the forum. I finished mine recently so it's pretty fresh in my mind, feel free to ask any questions. George
 
Is that nose made with CFRP? If so, did you build it or did you buy it somewhere?

The reason I ask is that I have been trying to design a manufacturing process for a nose for an L3 (L4 in Canada) rocket
 
I built a Wildman Eagle Claw. Nice kit, fun to fly. Loves 2550 motors.

Some thoughts: you don't sound like you are going overkill for this kit - you ideas at the top seem reasonable. I went with 25' of 9/16 TN for the apogee, and 15' for the main. I also like ubolts better when there is space for them, since they can't unscrew themselves - though there are other simple things you can do to prevent this. I use the nosecone interior for my tracker. Good place for it, keeps it away from the altimeters. I use a 84" Spherachute for the main (my rocket is 16 lbs without motor), and a large enough nomex for a burrito - space is a little tight, but makes it without too much trouble. I also use 3 2-56 shear pins to hold the nose cone on. I used extreme rail buttons, but std buttons will also be fine. Like it appears you are planning, I also use 1" kevlar strap leaders near the charges to avoid burn damage to the TN cords. I also like to cover/wrap the charges with small bits of sacrificial nomex or kevlar attached to the cords to stop the worst of the hot particles before they even get to the chute protectors.
 
I built a Wildman Eagle Claw. Nice kit, fun to fly. Loves 2550 motors.

Some thoughts: you don't sound like you are going overkill for this kit - you ideas at the top seem reasonable. I went with 25' of 9/16 TN for the apogee, and 15' for the main. I also like ubolts better when there is space for them, since they can't unscrew themselves - though there are other simple things you can do to prevent this. I use the nosecone interior for my tracker. Good place for it, keeps it away from the altimeters. I use a 84" Spherachute for the main (my rocket is 16 lbs without motor), and a large enough nomex for a burrito - space is a little tight, but makes it without too much trouble. I also use 3 2-56 shear pins to hold the nose cone on. I used extreme rail buttons, but std buttons will also be fine. Like it appears you are planning, I also use 1" kevlar strap leaders near the charges to avoid burn damage to the TN cords. I also like to cover/wrap the charges with small bits of sacrificial nomex or kevlar attached to the cords to stop the worst of the hot particles before they even get to the chute protectors.

What is the descent rate you get? I just ordered a 96 inch Spherachute for a rocket that I expect to be 15 pounds empty.
 
Last edited:
OK Hold the Bus! Pay close attention here! The filament wound is really cool but there might be a "Gottcha" involved.

Dry fit your tail cone to the body tube and compare the length of the 36" motor mount to where the top centering ring will adhere to it ABOVE the upper fin slots. If it was cut like mine, you're going to come up short.

What I did to correct this was to sand the ID of the tail cone so it would allow the OD of the motor retainer to fit inside the tail cone. Looks pretty cool like this but it still didn't get me enough room so I took about 1/2" off the aft end of the body tube.

I did it this way instead of just cutting the tail cone shorter for cosmetic reasons.

Totally awesome kit, just make sure you've got a good build plan.


Flush Retainer.jpgSander For TC ID.jpgNot Flush Retainer.jpg
 
What is the descent rate you get? I just ordered a 96 inch Spherachute for a rocket that I expect to be 15 pounds empty.

About 20'/sec. Its a glass kit, and lands on farmland. Main at 500'.

What I did to correct this was to sand the ID of the tail cone so it would allow the OD of the motor retainer to fit inside the tail cone. Looks pretty cool like this ....

I did this too, for cosmetic reasons. Don't remember the motor tube being too short. I did trim a bit (1/2"?) off the tail cone though so the retainer shoulder would fit inside - this way the OD of the retainer ring is about the same as the boat tail, so it does not stick out into the airstream.
 
Last edited:
I did this too, for cosmetic reasons. Don't remember the motor tube being too short. I did trim a bit (1/2"?) off the tail cone though so the retainer shoulder would fit inside - this way the OD of the retainer ring is about the same as the boat tail, so it does not stick out into the airstream.

Nope, motor tube was every penny of 36", tailcone on the long side.

Hindsite being 20/20...yeah, the smarter way to go by cutting the TC. A little skittish about cutting a cone straight at the time.
 
Guess what I got today... Guess what issue I found today...

Giant Leap - 54mm QWIK-LOK System
View attachment 182689

It doesn't fit the FG MMT... I actually got it to barely start down the tube, and could probably pound it the rest of the way. But, that does leave any room for what I believe is a requirement. EPOXY.

NOW WHAT!?!?

Willie

Can you measure the ID of the threads and the OD of the retainer body?

Thanks.
 
Willie,
On my Eagle Claw I initially set it up with an original Slimline retainer. It took a fair amount of sanding to fit, Slimline does not offer versions for different tube material like Aeropack. After I put the boat tail on I decided to use the Qwik-Lok and it was a much tighter fit. I no longer had access to sand so I tapped it in place after putting in the JB Weld. There are grooves in the retainer to hold the glue and I'm confident it will not come off, ever. I have had the same experience with Aeropack having to sand the motor tube and I did have the correct fiberglass version. I read here on the forum G-12 tube is a little larger in diameter than G-10, if true it explains the tight fit. I doubt it's worthwhile for Aeropack and Slimline to change programming for something a few minutes of sanding will take care of.

My Eagle Claw is also going to have a launch weight over 15 pounds so it's not just you. I don't know who computed the 7 pound weight on the parts breakdown sheet, that is not at all realistic.
 
Working with a set a calibers, the best I can tell is the MMT OD is equal to the ID of the retainer at 2.280". It is possible that the MMT is .002" bigger that the retainer. Or, .0005 smaller.

It is too difficult to tell using my calibers.


Willie

I'm more interested in the OD of the whole thing: I'd be embedding it into a centering ring so that it's nearly flush.
 
The sanding thingy I have in the second picture made fairy quick work of the tail cone ID with a cordless drill. I bet an automotive store might have something similar for boring cylinders.
 
The Qwik-Lok Retainers OD is 2.464"

The Boattail Aft ID is 2.400.

If I stick with Qwik-Lok, I too want to recess the retainer nearly the entire way up in the boat tail.

Thanks.
 
Back
Top