Howdy, Leviathan Build, and some questions

My wife says it needs to look like Evel Kneviel's Snake River Rocket, but I'm not convinced I can swing that. Got to find a source for metallic gold starts. Ha.

By the way Nytrunner, your's looks awesome. Nice work.

Whatever your other paint schemes are, I like to paint my aft CR flat black. It'll get sooted up anyway so you may as well own it. Flat black also hides an awful lot of sins in the unevenness department.

For reforming the tail with a coupler slice, I have about 50 tiny clothespins I got from IIRC Hobby Lobby so very small bits can be forced to conform to sturdier bits.

I don't think I have a picture of the Big Daddy I did this way, but here's a demo of how small the pins are / how precisely they can be placed.

dhbarr said:

For reforming the tail with a coupler slice, I have about 50 tiny clothespins I got from IIRC Hobby Lobby so very small bits can be forced to conform to sturdier bits.

I don't think I have a picture of the Big Daddy I did this way, but here's a demo of how small the pins are / how precisely they can be placed.View attachment 370486

Click to expand...

"Honey, where are my clothespins?" (wife calling from laundry room)

boatgeek said:

Whatever your other paint schemes are, I like to paint my aft CR flat black. It'll get sooted up anyway so you may as well own it. Flat black also hides an awful lot of sins in the unevenness department.

Click to expand...

However, gloss paint is smoother than flat paints thus it should be easier to wipe clean.

Ok, got to work on this a while. I think the Gflex epoxy may not have been the best choice for external fillets, they are taking days to dry and seem like they will be a bit soft to sand cleanly. We'll see, might be time to get out the high build primer. I was able to salvage an Aeropac retainer from the dead Arreaux. Tonight I attached the retainer with JB Weld and smeared a bit around the aft centering ring.

I also started looking at the recovery components. Keeping with the theme of things I have the garage or basement I salvaged some kevlar shock cord from the Arreaux, and found a couple of swivels and a quick link. The first kevlar cord is mounted to the motor mount and I attached a swivel to that with a bowline and some epoxy to hold the knot tight. Next is a longer section of kevlar that already had a couple of loops tied in it. The second length of cord passes through a nomex chute protector, attaches to another swivel and then to a quick link along with the chute lines. This assembly should hold the bulk of the weight of the rockets. I attached the nose cone to the the quick link with a smaller length of cord. I feel that it's probably ok to use a smaller cord and the stock nosecone attachment since the only weight on this will be the nosecone itself. Hopefully you can trace the lines in the picture below and let me know what night not work.

I'd still like to pick up a Jolly Logic Chute release and try to get it incorporated into the recovery system for a poor man's dual deploy. I'm assuming it'll be connected to the quick link too. I'll try to get a bit of sanding done this week and start on priming and paint. Has anyone had any experience with Dupli-Color High Build Primer? Can I avoid puttying the cardboard seams if I do a coats with sanding in between?

Hi KDA. I did my level 1 cert with a Leviathan as well. However, I flipped the fins so they swept up and not back. Did this for two reasons. One, I liked the look. Two, for my cert flight I felt it lessened the chance of a broken fin on landing. I also live in Denver and get down to Apogee in person when I need something there. I did use the 1010 rail buttons with the tee nut ‘backer’ that Appgee sells on my Leviathan and they work great. Have used them on all my builds since as well.

I’ve never flown at the Hartsel Tripoli site, but hear it’s beautiful. Another launch option for you to consider would be NCR (Northern Colorado Rocketry). NCR is a joint Tripoli/NAR club, has an on-site vendor (Moto Joe Rocketry) selling CTI and AeroTech motors, and holds monthly launches weather and launch site conditions permitting. NCR has 2 launch sites in the Pawnee National Grasslands (a summer site and a winter site). Lots of room, high waivers and a good group of people (as you will find with most rocketry clubs). From my house in south Denver it’s about an hour and a half to our winter site and about 15 minutes longer to the summer site. Take a look at Southern Colorado Rocketry in Pueblo too. I used to fly there when I first got into high power since my dad lived there. Switched to NCR after my dad moved. It’s also a little farther from me and no motor vendor.

For future reference, when you extend fin slots to the end of the airframe and have trouble getting it to fit the aft centering ring again, just use a big hose clamp or zip tie and pull it back together. Of course, this assumes that the fins aren't flush with the end of the airframe. I've done this several times with good results.

I packed the chute and wrapped it in the nomex and it's a pretty loose fit. Loose enough that it slides all the way down to the top of the motor mount. I'm sure there will not be a problem getting the nose cone off, blowing lightly through the motor mount and it pops right off, but I'm worried about so much of the ejection charge gasses going aorund the chute that it doesn't come all the way out of the tube. It seems like a long way down there. A few possibilities that I can think of:

1. I'm paranoid and it'll be fine.
2. I need to add a structure / baffle of some sort to keep the chute up near the top of the body tube.
3. I need to attach a small drouge chute or streamer to the nose cone so that when it pops out it drags the main chute out.

Any thoughts?

BTW, kjkcolorado, thanks for the info I discussed it with the scouts and I think the Pawnee site would make a better camp out so we are going to plan on bringing them to the May 31st / June 2nd event.

It'll be fine, the leviathan has been recovering with nose-blow for a decade. The nosecone flying out pulls the chute into the stream.
What you can do is attach your chute to the shock cord closer to the nose than the booster, and loosely wrap the shock cord around the bundle a couple times so it yanks it out.


That being said, trying new things is good too. I put a 3" to ~38mm ring in one of mine to keep things forward
Or try a streamer to do something new too!

If I may suggest:

Don't thread the chute protector over the shock cord. it can ride up and foul the chute itself. I like to make a loop / bite in the shock cord, low down, then pass this thru the eye in the blanket / protector, then pull the blanket / protector thru the bite / loop. pull tight. you should h\now have the blanket / protector attached to the cord with a lark's head / cow hitch knot. You can then remove it just as easy.

I, personally, stay away from hardware I don't' really need. In this case, the swivels & the hitch clip, they just add weight. You can knot the cords where you need to tie things in. a swivel on the chute shroud lines is about the only place I have swivels..

I typically tie a loop in the shock cord, about a foot or so below the NC. this is were I tie in my chute. I also, typically, gather all my chute shroud lines, find the middle of then bundle, and put an overhand knot in the bundle. this way, the chute won't shift under load and turn into a flag! (the way you have it attached to the quick-link, can cause the chute to fill unevenly, and slip sideways.. And, with the two loops (one in the chute, one in the shock cord), I pass one loop thru the other, then pass the chute back thru so it's tied in with another lark's head / cow hitch knot.

A mentor of mine also suggested a small 10" chute at the tippy top of the shock cord, so that it blows out first, and its drag helps pull all the laundry out..

The leviathan is about the biggest rocket where I would rely on the moulded attachment point for my cord & such..

Go buttons, ditch the launch lugs.

I've thought of adding a shelf in mine to hold the laundry. But it doesn't seem necessary. Just make sure it balances with the laundry in the worst possible place.. I've launched min pu-lenty of times like this, even on a baby H.. just add nose weight as needed. (I've used a quick-link & some washers on the NC..)

There are a few pick of mine on the forums somewhere..

Dr Wogz, thanks for the suggestions. I did eliminate the upper quick clip and attached the chute lines directly to the swivel. I also like the idea of keeping the nomex down low. I still hope to do this with a JLCR so keeping the nomex out of the way after apogee but before the chute releases seems like an excellent plan. As for the other hardware, the lower swivel was just because I already had a couple of lengths of kevlar cord with loops so it was an easy way to join them, but I suspect I can just go loop to loop with a larks head and get it out of there too.

KDA said:

BTW, kjkcolorado, thanks for the info I discussed it with the scouts and I think the Pawnee site would make a better camp out so we are going to plan on bringing them to the May 31st / June 2nd event.

Click to expand...

Wonderful! Look forward to seeing you all there. If you want/need any additional information, don’t hesitate to reach out to me.