Sirius Rocketry's Mid-Power Interrogator Build

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FatBoy

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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.

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FatBoy

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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.....

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FatBoy

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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...

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FatBoy

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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...

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FatBoy

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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...

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FatBoy

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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....

4 Fins 5 - Copy.JPG

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FatBoy

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A small strip of the reinforcing material needs to be removed from the top of each wing where the rudders get attached. After that, a dowel was glued to the outside edge of each wing tip.

After that was dry, I taped the body to the table and glued the wings onto the top of the intake tube butted up against the long dowel that was glued to the top centerline. The strakes were also added to the lower sides of the intake tube...

4 Fins 7 - Copy.JPG

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FatBoy

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A few little detail parts get glued to the underbelly. These include a 3/16" launch lug which is hidden between the wing and intake tube, two little ramjet tubes and two dowels....

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FatBoy

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The nose cone is a pre-weighted resin material that counterbalances the weight of 24mm E and F reloads. A small screw eye gets glued into the back of the resin nose....

7 Nose 1 - Copy.JPG
 

FatBoy

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I used some more watered-down wood filler to patch up a few minor seams and sanded everything smooth....

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FatBoy

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I sprayed the entire rocket with Rustoleum Painter's Touch Ultra Cover 2X white primer. This stuff dries fairly fast and is easily sandable.

After the Primer was sanded, I painted the rocket with Rustoleum Painter's Touch Ultra Cover 2X white gloss spray paint.

The primer and paint are available at a lot of hardware stores, and I found them at Menard's for less than $3 per can....

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FatBoy

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The water-slide dacals were next. This was intimidating too since there are about 40 of them that came on three full-color sheets.....

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FatBoy

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Luckily for me the decals are extremely robust and I didn't tear any of them while applying them.

Here are a few shots of the finished model.

I am hoping to launch this at our next club launch in two weeks using an E18 reload. I will also be bringing it to NARAM to fly there.

My impression of my first Sirius kit was incredible. It is an amazingly easy kit to build in spite of all of the detail, and it makes us mediocre builders look good!! Lots of color decals really add a lot of character to this model, and I would highly recommend Sirius to anyone.

Now, back to dreaming about that Saturn V.....

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Bravo52

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Awesome build. All of the Sirius kits are great. My favorite is the Cestris.

You did a great job on the Interrogator! Get some flight pictures!
 

FatBoy

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Thanks, Jerry, David and Tony!! I will get the flight pics in a few weeks!
 

FatBoy

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I forgot to mention.... The specs on this rocket state a finished weight of 4.5 Oz, and mine weighed in at 5.2 Oz - not bad considering I tend to go heavy on glue, wood filler and paint.

Another thing I wanted to mention.... The specs also say this kit is a skill level 3. I know there is some type of guideline that states what skill level a kit should be rated at, but these instructions were so clear and straight forward, that I would think even if someone has never built a skill level 3 rocket before, that they should have no problems with this one if they take their time and follow directions.

Sirius gets an enthusiastic two thumbs up! :clap:
 

jpaw33

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I flew my mid-power interogator last weekend on a D12-3.It was by far the best flight of the day!!!And we launched alot of rockets.She flew very high and straight on that engine and impressed everyone.This is one highly recommended rocket.:D
JPAW
 

BobCox

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My impression of my first Sirius kit was incredible. It is an amazingly easy kit to build in spite of all of the detail, and it makes us mediocre builders look good!! Lots of color decals really add a lot of character to this model, and I would highly recommend Sirius to anyone.
I agree completely about the quality of Sirius kits. I have to contradict you on one point, though -- I have seen some of your other work and you are far from a mediocre builder.

Anyway, great job!
 

FatBoy

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JPAW... Good to know it flies well on a D12. In that case I might just fly mine this weekend at out club picnic if the wind is calm (we have a picnic at a smaller field than where we have our regular launches). Otherwise I will fly it the weekend after at our regular launch.

Bob.... Are you saying I am less-than-mediocre??? (j/k) Thanks! Compliments from a pro-master like yourself are always encouraging!
 

FatBoy

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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.....

Launch - Copy.jpg
 

Pantherjon

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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..:rolleyes:
 

FatBoy

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

Scotty Dog

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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

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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

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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

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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

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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

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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.
 
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