Estes Leviathan - Build changes for Cert?

Hello All,

I picked up an Estes Leviathan as a birthday present to myself (thanks me!). I have not yet started the build process yet, but I have no doubts that it will go smoothly. This is my first foray into MPR, and I think I may want to try to get my L1 down the road. I've read lots of great build tips so far about this rocket, and I already have some mods in mind. I plan to fly this a few times on low F's to get a feel for how it flies before going to any thing bigger.

Now onto my q;

What build changes might be smart to prepare for a cert attempt with this rocket?

Welcome to the forum!

Here is a thread I recently posted on the same question:

https://www.rocketryforum.com/showt...-all-Estes-Leviathan-builders-Let-s-talk-mods

Have a really big recovery area? Seriously, I don't think you really need to do much to it - it is already designed for the G80, so I don't see any reason it couldn't stand up to a small H like an H128 or H90. It'll just go higher and recovery may be more of a challenge. I suppose you could get some 3" body tube and a coupler from BMS and add an E-bay to it and make it dual deploy, but otherwise I think you'll be fine. I finished mine and have yet to finish or fly it, but it is nice and sturdy. Well, one thing that just came to mind is that you might want to change out the shock cord for nylon, and beef up the attachment method (I put in a baffle and attached the shock cord to that), but I would recommend that mod for anyone.

I probably should have listed my planned mods in the OP (most taken from the mods thread);

10 foot kevlar shock cord, in addition to the stock one
barrel swivel at laundry connection
eye bolt instead of tri-fold paper mount
TBD baffle design


Has anyone cert'd with this model yet?

I'm guessing people get them from McMaster-Carr www.mcmaster.com

That seems to be the favorite for hardware...

I tried the local West Marine, but what they have is a bit pricey... (though it's good to know I can hit them up on launch day if I need one in a pinch)

Green Jello said:

Where do you guys get barrel swivels? I looked at both HD and Lowes and couldn't find any.

Click to expand...

Green Jello said:

Where do you guys get barrel swivels? I looked at both HD and Lowes and couldn't find any.

Click to expand...

Most of the rocketry vendors have large swivels. I got my last one from LOC Precision. Top Flight has them, too.

welcome to the forum
- 1st do not use the engine block
- 2nd buy a 12 foot piece of 1/8" Kevlar and use that as your shock cord
- 3rd attach the shock cord to the motor mount
- 4th launch and get Lvl 1 cert.


TA

This is a beautiful rocket to build and fly, I'm sure you'll enjoy it. I built mine the way you are wanting to build yours with a baffle system but made my own which is very simple.
https://www.rocketryforum.com/showthread.php?40747-Estes-Pro-Series-Leviathan-With-Baffle-System

- 1st do not use the engine block
- 2nd buy a 12 foot piece of 1/8" Kevlar and use that as your shock cord
- 3rd attach the shock cord to the motor mount
- 4th launch and get Lvl 1 cert.

Click to expand...

This is a bit of the info I was after. Excuse my ignorance, but why would I leave the engine block out? Is that to fit longer motors? If so, how is thrust contained? The last time I "left" a motor mount out, my Commanche III came down in flames....

I am also learning that with enough kevlar length, there is no need for any elastic shock cord.

I think a nomex blanket may also be in order.

Not installing the engine block won't restrict you from using longer motor casings.

smiler82 said:

Excuse my ignorance, but why would I leave the engine block out? Is that to fit longer motors? .

Click to expand...

Yes. Most motors have a thrust ring molded into them that butts up against the back of the motor tube, preventing the motor from going any further. Using an engine block would just limit your motor choices.

Edit: too slow.

Alex

Thanks, I learned something new...

I'm used to LPR BP motors with no lip...

smiler82 said:

This is a bit of the info I was after. Excuse my ignorance, but why would I leave the engine block out? Is that to fit longer motors? If so, how is thrust contained? The last time I "left" a motor mount out, my Commanche III came down in flames....

I am also learning that with enough kevlar length, there is no need for any elastic shock cord.

I think a nomex blanket may also be in order.

Click to expand...

A nomex blanket is a good idea. And yes the longer the Kevlar shock cord is will eliminate the need for a elastic cord and help prevent a zipper.

This is how you attach a Kevlar shock cord to the motor mount.
Cut a small notch on the inside of one of your centering rings 1/8" by 1/8" will do.


Then loop the shock cord around the motor tube and tie it off and thread the other end of the shock cord through the notch of the centering ring. Put a healthy amount of epoxy around it , and thats it.


You can stuff the loose end of the shock cord into the motor tube so you can protect it from glue when you glue it all together. Give it a good shake to get it out when it is all dry.


TA

Your planned mods are fine...though you don't need to ditch the tri-fold shock cord mount. I have seven flights on mine (F-H) with the stock shock cord and mount with no issues so far.

I did my L1 cert using a CTI H87 in my Leviathan back in late August with a configuration very similar to what you're thinking. My baffle is the two-tube style that Semroc sells, but I had to have the ply disks cut by BMS to fit the tubing sizes.

Great flyer.