Sirius Rocketry's Mid-Power Interrogator Build

[FatBoy]

I was first introduced to Sirius Rocketry (www.siriusrocketry.com) when I met David and Evie Miller at NARCON 2007. I fell in love with their Saturn V, and it has been on my wish list ever since. But in the mean time, I purchased and built my first Sirius kit - the Interrogator.

Sirius makes the Interrogator in three sizes:
- Standard Interrogator - 19.9" long -18mm A, B and C motors
- Mid-Power Interrogator - 27" long - 24mm C, D, E and F motors
- Interrogator G - 44.1" long - 29mm F, G and H motors

I got to see the Interrogator G fly at NSL2009, and it is amazing, but I decided to settle on getting the Mid-Power Interrogator, kit #S-012.

The kit is outstanding. It comes complete with a 12 page illustrated instruction manual, body tubes, balsa sheet, self-adhesive reinforcement sheets, dowels, 18" mylar parachute, Kevlar and elastic shock cords, a resin nose cone, tube cutting pattern, fin cutting pattern, and 3 sheets of decals.

[FatBoy]

The instructions start out with several modeling tips that can help with this assembly and be applied to other rockets too. The first step is assembling the motor mount. This was straight forward and involves marking the tube, adding a motor hook, a thrust ring and some centering rings, then tying the Kevlar shock cord to the motor tube.....

[FatBoy]

Next was the body tube assembly. Before I started this step, I filled the small spirals with a mixture of watered-down Elmer's Wood Filler, and sanded them smooth. The body consists of the main tube and an intake tube. The intake tube gets a 45 degree angle cut on it, and the kit comes with a wrap-around template for making the cut. This template is also a marking guide for the strake locations and the top centerline. Once the cut is made, the intake tube gets glued to the main tube 11/16" from the end...

[FatBoy]

Next, a 45 degree angle was sanded at the end of a dowel that gets glued to the top of the intake tube along the centerline. This dowel is where the wings get mounted to later on. Then the motor mount gets assembled into the tube that gives the back end a three-step look to it...

[FatBoy]

The wing assembly looked a little intimidating to me at first, but it actually went fairly well. After cutting out the fin templates, I used the template to cut she shapes out of the balsa sheet. The main wing gussets have a slight curve to them, but all the other edges are straight.

Both the main wings and the rudders have gussets that need to be glued onto them. I used my Standard Rocket Assembly Tool to keep them flat with magnets while the gusset joints dried.

At the end of this step you have two wings with gussets, two rudders with gussets and two strakes...

[FatBoy]

The next step was to reinforce the fins with self-adhesive reinforcement material. I peeled off the backing and stuck each piece to the sticky side, then I carefully trimmed them with a hobby knife. The process is repeated for the other side. After that, I used a kitchen spoon to burnish the material onto the fins.

I applied some CA to all of the exposed balsa edges (except the root egdes) and sanded them smooth.

I have only used this process once or twice before on other rockets, but it really makes strong laminated fins with no need to fill any of the balsa grain with sanding sealer or wood filler....

[FatBoy]

I flew this rocket today on a D12-5. Absolutly perfect flight! Even though it was fairly windy, it still flew straight up. I was going to try it on an E reload, but ran out of time.

You can even see the white motor plug bounce around in the second, third and fourth pictures.....

[Pantherjon]

Awesome build Jeff! Oh, and flight too! Let us know how it goes with an E reload next week!

I have one of those kits in a tote here..One day it will get built..

[FatBoy]

Thanks, Panther. You should move yours up in the build cue - it is a lot easier to build than it looks!

[Scotty Dog]

Very,very, clean build. Not much else to say. Must take nerves of steel to put ALL those decals on. Looks to me like you got them ALL on PERFECT. Scotty Dog

[FatBoy]

Thanks, Scotty Dog. Those decals scared be a bit at first, because I was afraid of ripping them or folding them. But after the first one I realized it would be a breeze. The decals are very strong. Not a single one tore or wrinkled.

[Sirius Rocketry]

Wow! Great launch sequence!

Have a great time at NARAM and say hi to all the MN folks for me!

David

I flew this rocket today on a D12-5. Absolutly perfect flight! Even though it was fairly windy, it still flew straight up. I was going to try it on an E reload, but ran out of time.

You can even see the white motor plug bounce around in the second, third and fourth pictures.....

[FatBoy]

Thanks, David!

I am getting excited about my first NARAM. I leave in two days, and after a few days in Rocky Mountain National Park and then visiting family in Colorado Springs, I should get to NARAM on Monday! Wish you guys could be there.

[Sirius Rocketry]

Thanks, David!

I am getting excited about my first NARAM. I leave in two days, and after a few days in Rocky Mountain National Park and then visiting family in Colorado Springs, I should get to NARAM on Monday! Wish you guys could be there.

We do too! Just way too much going on this year. Our kits will be represented at NARAM though, just stop by the Balsa Machining Service booth.

Best of luck at your first NARAM, and say hello to everyone for us!

[FatBoy]

I flew this Interrogator at NARAM last week on an E18-7 reload with an Altimeter One on board. I didn't want to drill a hole in the body to vent the altimeter, so I don't know if the reading was acurate or not, but it recorded 1,319 feet!!!!

I will post a picture later of it taking off. It accelerated so fast that the pictures didn't turn out too great. Awesome rocket.