I’m working on the Hostile Projectiles V-2. After reading through the instructions I can see that once again Steve provides the builder with the ability to leverage some new and interesting techniques.

I can tell already that this is going to be a great flier. The resign nose cone and tail cone look fantastic. Once finished this model will present a very scale like appearance.

Parts
One boat tail and nosecone
BT 60 body tube
BT 20 engine tube
engine clip
small centering ring
large centering ring
engine block ring
clip and swivel
screw eye
shock cord
trash bag parachute
parachute line
styrene to mount the eye screw to nosecone
sheet of 9x4x1/8 balsa
Templates for fins
Stick dots to reinforce the parachute holes
half round styrene for the fin detail
instruction CD


The first step is to sand the main body tube ends to make them even.

Next I washed the nose cone and tail cone in warm soapy water. This is to remove any leftover mold release. If you want your primer to stick correctly this step must be performed.

From there I lightly sanded the nose cone and tail cone, being careful not to sand the detail off. I filled a couple of minor imperfections with Bondo spot putty, but to be honest I like the level of realism the parts convey so I didn't do too much work on either part. I then primed them and set them aside. The instructions recommend Tamyia primer but I used the Krylon I had on hand.

Next I applied the fin template to the balsa sheet and cut out the four fins. The instructions call for the fin templates to be saved to be used in a step later on in the build. That step is one of those techniques that Steve utilizes in his builds that help to give the model an added level of realism.

I then sanded the fins and beveled the leading, trailing and outer edges.

Next up I sealed and primed the fins. Steve provides some great suggestions on how to get a very nice finish by utilizing Bondo Spot putty, but I was able to get a nice finish using Elmers Fill N Finish.

Next up will involve using that very cool technique I referenced above.

More to come.

Attached Thumbnails

 

__________________
I plan ahead that way I don't have to do anything right now

Mine is finished. I had hoped to fly it Saturday, except the weather is now expected to be in the low 30's with snow

I have a write up for an EMRR review but a few points of note:

1. Go light on the 3M Super 77 if you want to reuse the fin templates. My fins are laminated in paper. I'm glad Steve provided the template in printable form. The fin scoring still worked out well. And I didn't have much filling to do.

2. I scrubbed the cones with steel wool, soap and water. When I thought I had scrubbed enough I scrubbed some more. There were still spots where the primer didn't stick. Enough was obviously not enough. I sanded and reprimed and all is well. Looks great in Rustoleum red primer! Waiting for better weather to complete the camo pattern.

3. I added a steel leader to the motor mount in lieu of the tri-fold shock cord mount.

4. I slipped a bit and now it is too heavy for a C6. I plan to fly it on a D13.

Attached Thumbnails

 

__________________
- Dick
NAR L2, member of MDRA and NARHAMS
*** My Rocket Dungeon ***My Our Planet Page***
Keeper of EMRR's Rocksim, CP, and recommended motors databases
Co-moderator of the MicroMaxRockets, microhybrids, and OddRocs Yahoo groups
Retired moderator of The Rocketry Forum

Looks great Dick. Good job.

Frank thanks for starting the build thread.

Get video of you flights guys. I will myself when I finally get out to my friends house out in Palmdale. Fianlly going to get some flying in.

Steve

__________________
We should build a Bridge to the Stars

Hostile Projectiles

Looks great Dick! I can't wait to hear how the first flight goes. I think it's going to be a great flier.

As for the snow, bring it on! I just bought a Yamaha RX-1 snowmobile earlier this week. It's got a 998cc 4-stroke 4-cylinder liquid-cooled engine in it and it flies.


Having the instructions on CD has it's advantages. Being able to re-print the templates being one.


The detail on the nose cone and tail cone make it harder to get all of the mold release off. I soaked them for a good long time before scrubbing.

Good luck on the first flight!

__________________
I plan ahead that way I don't have to do anything right now

Bump.

Steve

__________________
We should build a Bridge to the Stars

Hostile Projectiles

OK before I get back to where I left off I need to apologize for being away from the build for so long. I ran into the perfect storm of having to be away for some business in mid December, followed by my end of year vacation followed by having to be away again for even more business afterward.

On top of that my new laptop had to be worked on because the internet functionality went belly up, leaving me with no way to post any updates.

On the plus side I was able to complete the build and test fly the rocket. What follows is the build progress followed by flight reports.

After I had cut out, sanded and sealed and beveled the fins they became chew toys for a pet who will not be named. In the end though it turned out to be a good thing because on the second go-round I found a trick that worked well for me.

After cutting out new fins, instead of beveling the edges before scribing lines into the fins as called for in the instructions, I cut out a second set of fin templates from the template found on the CD and taped one template to each side of the four fins. Then per the instructions I scribed over pre-printed lines on the templates using a ball point pen which gives the fins a very cool 3-d look. I did the scribing first because scribing the lines before beveling made it easier for me to bevel the fins to spec. There were a couple of scribe details I left out which was a personal preference. The bottom line being that you can get to a great level of detail if you scribe everything out.

The fins came out looking excellent. The scribing technique is an excellent way to easily bring detail to an otherwise flat fin. I then attached the fins to the boat tail using epoxy and sealed them using diluted white glue. I then primed the whole boat tail did some light sanding and primed again.

Attached Thumbnails

     

__________________
I plan ahead that way I don't have to do anything right now

Next up was the motor mount build. You are asked to make a slit for the engine hook ½ inch from the end of the motor tube. However looking at the pictures in the instructions it looked to me that the hook started from more like ¾ from the end of the tube. This is important since if you start the hook as specified at ½ inch from the end of the tube and also mount the tube as directed, the hook will be too close to the rocket and it will be difficult to get engines in and out of the motor tube.

I had to sand down the larger upper ring quite a bit to make it fit. The instructions tell you to attach this ring flush with the upper end of the engine tube. I moved it to cover the upper end of the engine hook. The lower ring is the tricky part and needs to have a notch cut out to accommodate the engine hook, and also needs to be peeled almost completely off layer by layer until it slides snugly into the tail end of the boat tail. A Dremel tool comes in handy to sand down the upper ring. An engine block is also installed on the upper end of the engine tube and a wrap of electrical tape is wound around the middle of the engine tube to hold the engine hook. Once it’s all set you glue it in with Epoxy. NOTE: You need to be very careful not to damage the thin detail at the tail end of the boat tail when you are cleaning it up and cutting the notch for the engine hook. I popped a small piece out but was able to fix it with spot bondo putty. By the way take Steve’s advice and don’t use this stuff inside if at all possible. You won’t make any friends as the smell moves through the house. It's great stuff though.

__________________
I plan ahead that way I don't have to do anything right now

Next up is to Epoxy a styrene tube to the inside of the nose cone. You also need to Epoxy a screw eye into the tube. The chute is attached via a swivel directly to the screw eye on the nose cone. The shock cord is also attached to the screw eye.

My main body tube looked a bit rough on both ends so I wrapped a piece of thin sturdy cardboard around the tube making sure the ends matched up exactly so that I could see where the tube was off. I taped the cardboard in place and sanded one end straight. I then moved the cardboard to other end, taped it down and sanded that end straight also. Without doing this I couldn’t be sure my tube would be straight when attached to the boat tail or the nose cone.

The instructions called for making two launch lug mounts, attaching one to the main BT and one to the boat tail. I mounted both lugs directly to the main BT using no standoffs.

From there I primed the entire rocket. I then had to decide if I wanted to wait for good weather to paint before flight or just fly primed. Based on the extreme cold and no end in sight I elected to fly primed.

Attached Thumbnails

 

__________________
I plan ahead that way I don't have to do anything right now

I determined the CP at 5 ¾ from the rear of the rocket. The CG (without nose weight) came in at 5 ¼ from the rear of the rocket with a B6-4 engine installed. I added .6 oz of nose weight to move the CG to 6 ½ from the rear of the rocket. The weight with B6-4 engine installed and prepped for flight is 3.7 oz. The boat tail with fins attached is 1.1 oz.

__________________
I plan ahead that way I don't have to do anything right now

The first flight was on a B6-4 in high wind conditions. Winds were around 15 mph with gusts up to 25 mph. I think all of the flights took place where the wind was gusting from the 20-25 mph range. Liftoff was excellent. The rocket headed straight up to about 100 feet where it weather cocked into the wind, not too badly either. I estimate the rocket reached about 200-250 feet, but as always my estimates are very rough. Ejection happened when the rocket was heading straight down but when the chute popped, everything worked fine and it landed gently in the snow. Of course the high wind dragged it through the snow filling it up before I could get to it. It was fun getting all that snow out to prep it for the next flight.

The second and third flights were also on B6-4’s because I couldn’t bring myself to load it up with a C6-5 knowing I would probably lose it to the wind. The flights were very similar to the first. I recovered both without incident. Both times the rocket was heading straight down when the chute deployed. I wish there was a B6-3 in production because that delay would be perfect for this rocket in extreme wind conditions.

The next flights will be on a C6-5 and I’ll also go with a B6-4 again with no to low wind conditions.

Attached Thumbnails

 

__________________
I plan ahead that way I don't have to do anything right now