Estes Nike Smoke Pro Series II 38mm Build

Finally, I got around to building my Estes Nike Smoke Pro Series II Rocket that has been sitting on my storage shelf for over a year now. There are several Nike Smoke rocket kits out there. I chose the Estes kit because of its very reasonable price, it had the tube diameter I desired, and it is easily modified for high power rocketry. The rocket is easy to build and I kept it as light as possible. By adding a short AV/payload section, I can fly it dual deploy, but I don't see the need for it.


The Nike Smoke I've built is single deploy 38mm rocket designed to fly on the Aerotech J-350W motor. It has 13 3/4" LOC motor tube installed using 4 LOC centering rings and the stock fin latch ring opened up to accept a 38mm motor tube. A custom built ejection baffle is also incorporated into the rocket body tube so I don't have to mess with a chute blanket. An Aeropack 38mm motor retainer is used to keep the motor in the tube. The body tube is laminated with three 2 oz. fiberglass wraps and Aeropoxy laminating resin. The rocket is assembled using Aerpoxy epoxy. The factory Estes fins were beefed up by gluing them together and filling them with Aeropoxy epoxy glue to stiffen them and beef them up as I designed the rocket for supersonic flight. This was done to prevent fin flutter primarily. The fins are glued to the motor tube and three centering rings on the motor tube. Overall the rocket body is stout and solidly built. Acme rail guides are used on the body tube for launching off a 1010 rail launcher. I had to make some custom shims to fit under the rail guides so the nose cone would not rub against the rail at launch. I di this using some 16 guage aluminum 1/2 wide flat bar stock I had on hand. This raised the rail guides high enough for the nose cone to clear the rail. Stainless steel quick links and eye bolts are used along with a 12 foot Top Flite 1/4" kevlar shock cord and the factory Estes nylon chute for recovery. I may switch to a smaller diameter chute to get the rocket down from altitude quicker. I'll have to fly once to see how the factory chute does first. My thinking is that an 18" chute may be the better choice to go with. I don't want the rocket lolly-gagging in the air on a long slow descent. A Perfect Flite Pnut altimeter is used in a custom made altimeter housing that attaches to the nose cone. A BRB 900 GPS tracking tramitter/antenna and the altimeter can be installed inside the nose cone, but I don't think it will be needed because the rocket will stay in visual range at altitude. However, if I want, I can install all the avionics in the nose cone on a special mount/sled I've built for it that screws onto the inside of the nose cone. All I have to do is cut a small hole on the bottom of the nose cone and slide it in and screw it down to the shoulder of the nose cone.

On an Aerotech J-350W -6, I sim out at Mach 1.08 with a apogee occuring at 3997 ft. On an Aerotech I-600R-6, I sim out at Mach 1.09 with appogee at 3597 ft. We shall see if it can go Mach or not. I am providing several pics of the rocket. All I have left to do is prime and paint it. I will provide additional pics of the painted rocket. As soon as I complete the paint job.

Looks beautiful. You have done a nice job on it.

Are you using the stock plastic fins? Just to let you know, I had them strip off on my maiden flight with a 29mm H140... I doubt they would take kindly to a J350. I would also second qquake2k's concerns about the nose cone attachment... put an eyebolt and backing washer in the NC shoulder.

cerving said:

Are you using the stock plastic fins? Just to let you know, I had them strip off on my maiden flight with a 29mm H140... I doubt they would take kindly to a J350. I would also second qquake2k's concerns about the nose cone attachment... put an eyebolt and backing washer in the NC shoulder.

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Says he filled them with epoxy.

I've never had a problem with the Estes chutes, but I'm probably going to put the 18" Top Flite chute (which is rip stop) I have on it to get it down faster. The winds here just aren't letting up. As for the NC attachment point, I could easily beef it up or just cut the nose cone bottom off and install a bulkhead plate and eye bolt. The only nose cdone I've ever had the shock cord attachment lug break on was a low power C- engine rocket years ago. Dam thing was too thin.

Yes, the stock plastic fins are being used. They are completely filled with Aeropoxy epoxy on the inside. They are very stout and well glued to three centering rings and the motor tube. In other words, the fins are solid epoxy with a plastic outer coating. I sacrificed a little more weight in favor of strength. On the nose cone, I will have to use a bulkhead and eye bolt. The way the shoulder is designed, you can't get a washer on the back.

Well I took a look at the nose cone to see what the best thing to is. If I cut the nose cone to install a bulkhead plate and eye bolt, there won't be enough shoulder left on the nose cone to hold it firmly in place. The best option I can see is to beef up the lug using aeropoxy epoxy. The way the nose cdone is designed (see pic), there isn't a lot of options one has to strengthen the shock cord lug or modify the nose cone. I usually use long ejection delay motors, to avoid early ejections. I'd rather have a late ejection than an early ejection. Most of the time, my rocket ejections occur well into apogee with no problem.

Lol, I just thought of something......I can cut two small fender washers in half, install one washer at each end of the nose cone lug using some small pan head sheet metal screws. Then I can take some small strips of carbon fiber material and wrap the lug with the carbon fiber cloth to thicken and strengthen it. Then I can use aeropoxy to glue it all together and spread out the load on the nose cone shoulder/base. I can get to the back side of the lug and spread more expoxy on the back side giving it even more strength. I think this will be my best bet.

qquake2k said:

Looks like a fun project! But a couple of thoughts. Is the Estes parachute strong enough in case of early or late ejection? The ones I've seen aren't ripstop. And I wouldn't rely on the plastic nose cone attachment point for the recovery harness. I've had them break.

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The pic with the quicklink on the plastic nose cone what I hope you don't do. I've found that if you tie the shock cord to the plastic nosecone, especially with that large loop, they usually hold up quite well. If you use the quick link, it will probably break a piece of the plastic out just the width of the quicklink. The metal hitting the plastic doesn't work, but tying the cord to the plastic will work well.

The other option is to put two holes in the base of the nose cone and thread the shock cord through and tie it off.

Handeman said:

The pic with the quicklink on the plastic nose cone what I hope you don't do. I've found that if you tie the shock cord to the plastic nosecone, especially with that large loop, they usually hold up quite well. If you use the quick link, it will probably break a piece of the plastic out just the width of the quicklink. The metal hitting the plastic doesn't work, but tying the cord to the plastic will work well.

The other option is to put two holes in the base of the nose cone and thread the shock cord through and tie it off.

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After some careful thought/consideration, I've decided to leave the nose cone alone and like you said, tie the cord directly to the nose cone instead of using a quicklock. This should minimize a hard solid jerk (metal to plastic). I can't run anything on the inside of the nose cone as it will interfere with my A/V sled and the altimeter/BRB 900 transmitter. I can glue a carbon fiber wrap around the lug and strengthen it some more if necessary, but I think it will be o.k.

I generally use medium and long delay ejection charges (depending on the rocket and motor of course) and don't really have nose cone ejection problems that cause breakage of the nose cone lugs. I think it will work just fine if I do it as you suggested.

Texas Rocketman said:

After some careful thought/consideration, I've decided to leave the nose cone alone and like you said, tie the cord directly to the nose cone instead of using a quicklock. This should minimize a hard solid jerk (metal to plastic). I can't run anything on the inside of the nose cone as it will interfere with my A/V sled and the altimeter/BRB 900 transmitter. I can glue a carbon fiber wrap around the lug and strengthen it some more if necessary, but I think it will be o.k.

I generally use medium and long delay ejection charges (depending on the rocket and motor of course) and don't really have nose cone ejection problems that cause breakage of the nose cone lugs. I think it will work just fine if I do it as you suggested.

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I would double think using the plastic lug on the nose cone if you are adding weight to the nose cone, either stabilizing weight or electronics. The weight become inertia and really ups the load on the shock cord attachment point. If you do want to do that, I would highly recommend altimeter deployment so you can control the ejection charge and keep it to a minimum required to reduce that inertia. Tying the shock cord to the lug on an empty plastic nose cone with just the added weight of paint is one thing, but more weight then that can be iffy.

I have upgraded a few Estes kits to fly on larger motors, besides confirming their stability I have always used the same method qquake2 has done, drilled out some holes in the NC and used kevlar cord to attach a D ring too.

Works so far...

Handeman said:

I would double think using the plastic lug on the nose cone if you are adding weight to the nose cone, either stabilizing weight or electronics. The weight become inertia and really ups the load on the shock cord attachment point. If you do want to do that, I would highly recommend altimeter deployment so you can control the ejection charge and keep it to a minimum required to reduce that inertia. Tying the shock cord to the lug on an empty plastic nose cone with just the added weight of paint is one thing, but more weight then that can be iffy.

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The only time I'll might fly electronics in the nose cone is when I fly on a J-350W motor which won't be very often. In addition, the rocket doesn't go that high. Right now, it sims out at at 3976 ft at Mach 1.1 on a J350-6 W Aerotech motor. I can easily maintain a visual on the rocket at that altitude. I may not even run electronics in the nose cone. I might just clip my Pnut altimeter onto the parachute link when needed. That is an option I have as well.

I think what I'll do is put some weight equal to the electronics and sled weight on the nose cone, test fly it, and see how it does. The worst thing that can happen is the lug breaks and I lose a broken nose cone. The rocket will be come down safely w/o the nose cone no problem. If that happens, I'll just get another nose cone and replace it. Also, I can decrease the motor ejection powder charge as well as it doesn't take much just to blow the nose cone and chute flying single deploy. The rocket will fly on G80 29mm motors no problem using an adapter. For "everyday" casual flying, I will use H128W-14 29mm motors which should take the rocket to alittle over 1800 ft.......keeps my motor costs down. Those motors use a smaller ejection charge than the ejection charge I usually load on a 38mm J-motor.
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Handeman said:

I would double think using the plastic lug on the nose cone if you are adding weight to the nose cone, either stabilizing weight or electronics. The weight become inertia and really ups the load on the shock cord attachment point. If you do want to do that, I would highly recommend altimeter deployment so you can control the ejection charge and keep it to a minimum required to reduce that inertia. Tying the shock cord to the lug on an empty plastic nose cone with just the added weight of paint is one thing, but more weight then that can be iffy.

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Hi guys,

I'm getting late to the party here. Just bought my first MPR Nike Smoke Pro for Xmas on special sale, and have been building her slow and strong, with epoxy on virtually every joint.
Someone suggested two part BSI epoxy on the centering rings and inside the fins, and that was done, as well as installing my first set of rail buttons with some small balsa backing epoxied in place.

Now someone has referenced adding weight (clay) to the nosecone, and I'd like to know why.
I was toying with including a small digital altimeter just to measure my Level One attempt, but not sure if that's wise or how to do it safely.

Any tips would be appreciated. (I was intending on looping the parachute shroud lines around the nosecone plastic lug (which seems sturdy) and a mentor had suggested a kevlar line around the motor mount, thru the centering ring, epoxied in, and with a flap of duct tape to protect the body tube from zippering. So the shock cord will become half a kevlar line for about two feet and then the full Estes elastic strap.

Tips?

Kirk G said:

Now someone has referenced adding weight (clay) to the nosecone, and I'd like to know why.
I was toying with including a small digital altimeter just to measure my Level One attempt, but not sure if that's wise or how to do it safely.

Any tips would be appreciated. (I was intending on looping the parachute shroud lines around the nosecone plastic lug (which seems sturdy) and a mentor had suggested a kevlar line around the motor mount, thru the centering ring, epoxied in, and with a flap of duct tape to protect the body tube from zippering. So the shock cord will become half a kevlar line for about two feet and then the full Estes elastic strap.

Tips?

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Nose weight will depend on how much weight you've added on the backside (epoxy much?) and how much motor you're putting back there. A simulation is your best bet to get an idea of where the CP is, then you can balance as appropriate with the motor of your choice.

The Kevlar cord at the motor mount is a good idea. I've got a Ventris with that setup, but I've tied the elastic below the tube mouth so that it's what hits the edge and decreases zipper chance. If you do add weight in the nose, there are ways of reinforcing the shock cord attachment. One is to just drill a couple holes in the cone bottom and feed the cord through those, another is to cut a hole in the shoulder, and epoxy a nut/washer on the inside for an eyebolt. I put a ring and bulkhead with an eyebolt setup up inside past the shoulder, but that takes more parts and work.