# Leviathan Build (for L1 cert flight)

### Help Support The Rocketry Forum:

#### lcorinth

##### Well-Known Member
I started building the Estes Leviathan, along with two other PSII kits, nearly a year ago. Eventually, I decided one of them would be my L1 cert flight vehicle. This one got finished first, so it'll probably be the one. It turned out nice, so I thought I'd post the build here.

Before we begin, I'm sure someone will tell me I overbuilt this thing, and it's true. But I had a year's less experience when I started, and I wanted to try some of the stronger HPR building techniques on something cheaper, and from what I understand, it's pretty common for HPR beginners to be a little overcautious with the building. So, the rocket's a little heavier than it could be, but it will be less likely to lose a fin.

I started with the fins.

I usually shape balsa fins on LPR models, so I wanted to see if it was doable with a plywood fin, since all I have is a hand sander. Since I wasn't sure how easy it would be, I swiped one fin from my Estes Scion (which is the same rocket, but with a longer body. The Scion has three fins, but since it's just repackaged Leviathan parts, it comes with four). I figured if it worked, I'd use the rest of the Scion fins for this rocket, and if it turned out terribly, then I'd just leave the fins on the Leviathan square, and I'd still have three fins for the Scion.

Whether it'll make this rocket fly better or not was kind of irrelevant to me, as I knew I'd be building heavy. I just like the look of airfoiled fins, so I figured I'd give it a go.

I mark where I want the tapers to be using a... actually, I forget what this thing is called, but it's a cheap tool for measuring hemlines on pant legs and such.

I'd have a slight taper on the leading edge with the actual edge rounded over, and a slightly longer taper on the trailing edge.

Connecting the marks...

I start sanding at about a 45 degree angle on the leading edge, down to the darker middle ply. This gives me a corner I can sand off, slowly working my way down to the line where I want the taper to start.

#### lcorinth

##### Well-Known Member
It's been a couple days since I started this thread, but I wanted to edit video before continuing.

I sanded all fins into airfoil shapes. Though I do have pictures, I also have video. I sand most of my LPR and MPR balsa fins into airfoils, but wasn't sure if I could do it with plywood with only a sanding block.

I gave it a go, and it turned out great. Just as easy as balsa, but you need a coarser grit of sand paper and a little more patience.

[video]https://youtu.be/AI2jtedVBwI[/video]

Edit: How do you guys upload YouTube videos that will play on the forum? Every time I do it, it just shows up as a link to YouTube.

#### REK

##### Sponsor
TRF Sponsor
It's been a couple days since I started this thread, but I wanted to edit video before continuing.

I sanded all fins into airfoil shapes. Though I do have pictures, I also have video. I sand most of my LPR and MPR balsa fins into airfoils, but wasn't sure if I could do it with plywood with only a sanding block.

I gave it a go, and it turned out great. Just as easy as balsa, but you need a coarser grit of sand paper and a little more patience.

[video]https://youtu.be/AI2jtedVBwI[/video]

Edit: How do you guys upload YouTube videos that will play on the forum? Every time I do it, it just shows up as a link to YouTube.
I think it only puts the link I'm not sure. I can view it on my phone just fine.

Is that a tungsten carbide sanding block? I swear I need to get me one to do neat airfoils.

Great video on the airfoil tip, thank you for sharing.

Alexander Solis - TRA Level 1 - Mariah 54 - CTI-I100 Red Lightning Longburn - 6,345 Feet

#### lcorinth

##### Well-Known Member
I think it only puts the link I'm not sure. I can view it on my phone just fine.

Is that a tungsten carbide sanding block? I swear I need to get me one to do neat airfoils.

Great video on the airfoil tip, thank you for sharing.

Alexander Solis - TRA Level 1 - Mariah 54 - CTI-I100 Red Lightning Longburn - 6,345 Feet
It's aluminum, from Great Planes. It's available online. I got mine from Amazon for around 8 bucks. It's by far my favorite tool in the box - in fact, I have two of them!

#### K'Tesh

##### OpenRocket Chuck Norris
TRF Supporter
When you want to add a video to your post... look at the bar that allows you to add a link, break a link (Unlink), Insert Image, Insert Video, (looks like a couple of frames of film), and adding a quote ( wrap "[" QUOTE] tags around selected text). Click on the "Insert video", paste in your link, and click on "OK", and it should be visible when you save your post.

Then again, I'm currently in China, so YouTube is spotty when the internet connection (or VPN) isn't 100%.

[video=youtube;AI2jtedVBwI]https://www.youtube.com/watch?v=AI2jtedVBwI&amp;feature=youtu.be[/video]

#### REK

##### Sponsor
TRF Sponsor
It's aluminum, from Great Planes. It's available online. I got mine from Amazon for around 8 bucks. It's by far my favorite tool in the box - in fact, I have two of them!

#### lcorinth

##### Well-Known Member
OK, after listening to you two talk about this great tool, I went over to Amazon.com and looked for it, and found FOUR different lengths... 5", 11", 18", 33" and one "gift pack" that was the 11" and two "rolls" of 220 and 150 grit.

So I decided to pop for the gift pack to try this thing out. Plus, by going over to my favorite podcast, I found if I order the \$20 gift pack through their link to Amazon, they get a cut of the money and helps them out as well!
It's my favorite tool in the kit. You'll love it.

#### lcorinth

##### Well-Known Member
I kept checking both the weight of the rocket and the CG throughout various phases of construction. One thing I did not photograph was fin fillets. I made them small, with Bob Smith 30 minute epoxy filled with microballoons.

Oddly, though, the weight did not seem to increase with the addition of fillets, and the CG didn't budge at all. This was really surprising. Yes, my scale is calibrated, and I found the CG by balancing the rocket thusly.

I don't know how to explain it, except that I kept the external fillets really small and mixed the microballoons in till I had a really thick paste. Perhaps that was enough that there really wasn't much epoxy in the end fillets.

Anyway, once the rocket was primed and sanded, I looked closely at the fins. Despite having filled the wood grain with CWF, there were some areas where it showed through. It had been a long time since I applied the CWF, and maybe some of it got knocked out.

I circled all the grain spots, so I wouldn't miss any.

I decided to try filling the imperfections with Bondo Spot and Glazing Putty, something I'd heard good things about here on TRF.

It was pretty easy to use - just smear a little on with the tube, and spread it flat with a putty knife, removing excess.

I also decided to see if I could hide the gap between the forward and aft body tubes, with some thick CA.

I'd sand this off, then re-prime. I wasn't sure how well it would work, since the two airframe tubes weren't a perfect match in all places, but I wanted to try it. I got really good results with this when I built an Astron Sprint XL, hiding the joint between the body tube and the plastic airframe. On that rocket, it all looks like one piece.

Next up: CG adjustment

#### lcorinth

##### Well-Known Member
Once I sanded down the CA and Bondo, I re-primed it, and gave a final sanding, ready for paint. Then I checked the CG, and plugged that into my sim. The rocket with no motor was over 1 caliber stability, but less than 2. With a G40 installed it was really marginal. According to my sim (and my technique of laying the unopened motor onto the back of the rocket with the CTI casing in the motor tube), with an H133, the rocket would be so close to neutral, I knew I had to do something.

I played around with the sim and the real rocket, and found that a mere 18 grams of nose weight would do the trick. I decided to go with modeling clay, since it's what I had on hand.

Rolled up into a snake and rammed into place with a dowel, the nose weight made the rocket safely above 1 caliber with motor installed.

If it seems like the clay is starting to come loose, I'll dribble a bit of epoxy in there, but for now it's pretty darned secure.

Next, I have to decide what colors to paint this darned thing. After nearly a year, I haven't figured that out.

My decision: Keep it simple.

#### lcorinth

##### Well-Known Member
I went with a base coat of Rustoleum 2X Flat Black - a paint I really like. Always goes on nice, and makes the rocket look big with it's flat surface color.

My painting booth is a cardboard box from a giant cooler. It's pretty big, but the rocket is slightly too tall for me to paint the whole thing. I put the nose cone onto a wand on my lazy Susan painting stand.

Did the whole rocket up in flat black. Then masked...

Now, the striptease...

Aaaaand... done!

Finally finish everything with some black rail buttons from rail-buttons.com. I ordered them for this rocket, because I only had white, and decided they should match.

I really love the way this rocket turned out. Can't wait to fly it. Will do my cert flight on a CTI H133 with a chute release, probably set for 400 feet.

Such a beautiful thing!

Then, I moved on to finish my Nike Smoke...

#### neil_w

##### Good at some things
TRF Supporter
That is a simple and elegant paint job. Very nice!

I need to experiment with flat paints a bit...

#### lcorinth

##### Well-Known Member
That is a simple and elegant paint job. Very nice!

I need to experiment with flat paints a bit...
Thanks!

The Rusto 2X flat black and flat white are two of my favorite paints. They always go on nice and smooth, and look great. I never get any orange peel, or worse - those spiky chunks you sometimes get with their gloss paints. The horror that happened to my Ventris yesterday... I can't think about it...

I've even (gasp!) put waterslide decals on the white, with no peeling or silvering over time (which I know you're not supposed to do, but I did it anyway). It's a nice, smooth paint.

The downside - it is a bit of a dirt catcher. The black shows dust like crazy, and the white does get smudges if you give it a dirty look. But that all wipes of easily.

#### lcorinth

##### Well-Known Member
And here's the successful cert flight, September 17, Amesbury, MA. Motor was a Cesaroni H133 with a 9-second delay. Really kicked!

[video=youtube;or7M_K0eCGA]https://www.youtube.com/watch?v=or7M_K0eCGA[/video]

#### K'Tesh

##### OpenRocket Chuck Norris
TRF Supporter
Lemme be the first to say "Congrats!"

Congrats!!!