Estes Pro II Series Prowler E2X Almost Stock Build

For the longest while I was convinced that the Estes Prowler Pro Series II starter kit wasn't available in Canada. Much to my surprise, after mentioning it to my local hobby shop, they called me with it now being in stock. I'm basically building this one concurrently with the Maxi-Alpha 3 in another nearby thread. However, since this kit is E2X, I am not planning to paint it, at least not yet. My daughter quite likes the hot pink look of it, and wants to keep that colour.

Here's the box it comes in:


And the parts to the Rocket itself:


In terms of size, it is thinner than the Maxi-Alpha 3. (2" vs. 2.6"), but it going to be about about a half-inch taller once it's all assembled.

In terms of assembly, my plan is to use primarily epoxy to put it together. The shock cord is attached to the interior of the tube with a plastic clip that glues in rather than the folded paper typical of lower-power rockets. I have some kevlar line, a few quick releases, and a few swivels, so I may modify the build to give this a bit more internal strength. I worry about the stock shock cord and zippers...

Any input would be appreciated, but at the same time this may also be helpful for those looking at a kit like this. I know it is an E2X, but it will be helpful for me to learn the basics of mid-power.

Here's a link to a thread I did about the Prowler with pictures I took of the model flying:

https://www.rocketryforum.com/showt...stes-PS-II-E2X-kits-Arrived&highlight=Prowler

That looks like a nice Kit. Does it say on the Box that it only flies 2000 Feet in Canada, but in America it will go 3000 Feet?

Cute. The 3000' is the max height estimate when used with the separate booster designed for several of the E2X Pro Series II kits. That kinda scares me.

Agatheron said:

Cute. The 3000' is the max height estimate when used with the separate booster designed for several of the E2X Pro Series II kits. That kinda scares me.

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I was'nt trying to be a Jerk, but it just sounded funny to me at the time. Sorry.

It was funny. I wasn't sure if others knew about the booster option. no offence taken.

First build update:



This is part glue and part dry fit. This is the engine assembly, with the fins dry fit onto it. The fins mount through the wall. Each fin comes in two parts. The instructions recommend using CA. Since I'm a model builder I decided to use polystyrene cement which is a lot more reliable than CA for assembling plastics. In part, CA has a habit of crazing/frosting plastic. The plastic rings and engine block are all glued using 5 minute epoxy.

I had thought about mounting some kevlar to this part of the assembly, but there's not really a good way to secure it to the engine mount. I'd have to drill through it and create a knot, but I wouldn't be able to wrap it around the tube given how the fins fit. I'd like to do it if possible, but the internal mount it comes with is far more robust than a standard trifold paper.

I'm letting the epoxy cure, and then tomorrow I'll be putting this into the body tube...

I'm following silently

Well, mostly silently lol...

Does the BT go over the forward black piece on the mmt?

Or does it slide all the way over the aft black ring?

*edit* O guess it couldn't go over the aft ring due to the ttw design? I'm confused lol

The body tube slides all the way over both mount rings so that the motor mount tube is flush with the bottom of the rocket. It actually works out nicely, and lines up perfectly with the slots that are already cut into the body tube. It may be confusing, but I think that may be part of the picture I included. The fins don't get mounted to the motor mount assembly until its inside the body tube. I had the fins to test alignment and making sure the fins will fit snugly once I get it in the tube. I expect to be adding some extra epoxy as fillets around the fins on the exterior to give it some additional strength.

One of the last parts of the instructions is installing the motor retainer, which is interesting compared to other rockets I've put together so far...

Just an FYI -- Make sure you use something like J.B. Weld or Liquid Steel on the motor retainer. Regular epoxy will melt if the exhaust is too hot.

Bat-mite said:

Just an FYI -- Make sure you use something like J.B. Weld or Liquid Steel on the motor retainer. Regular epoxy will melt if the exhaust is too hot.

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That hasn't been a problem for me with any of the four PSII E2X models I have built and flown.
I just used regular 30 minute epoxy and it worked fine.

tis more of a possible problem with metal retainers than plastic, plastic doesn't conduct heat worth a darn, so by the time the epoxy gets soft you don't have a retainer.
Rex

Rex R said:

tis more of a possible problem with metal retainers than plastic, plastic doesn't conduct heat worth a darn, so by the time the epoxy gets soft you don't have a retainer.
Rex

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I flew my Leviathan at URRF II five times. On the last flight, when I tried to unscrew the retainer knob, the entire thing (threaded part and all) came off. I used 5-minute epoxy. Some other problem, then?

epoxy* doesn't stick well to smooth ABS plastic, which is why you need to rough up the plastic. I've been using my dremel to put grooves on mine so that the epoxy has something to 'key' into.
*nor does much of anything else. although CA has been used with some success.
Rex

I did rough it up. Maybe the problem was with the motor tube instead of the threaded retainer ring.

The motor tube is pretty slick. I'll give that a try when it comes time to glue on the retaining ring...

Quick update with a pair of pictures. I mounted the motor mount tube, glued in the fins as well as the launch lugs. It looks mostly done from the outside:



I still have to do the parachute mount, as well as doing epoxy fillets for around the fins, as well as the motor retainer ring. I had enough epoxy leftover to do a single fillet around one side of the fins. I want to be safe on this one even if it does feel pretty solid as it stands now.

Also, here's a size comparison with my current Maxi-Alpha 3 project:


The Prowler is marginally longer in overall length, and is certainly a longer body tube. The Maxi-Alpha 3 looks beefier.

Initiator001 said:

That hasn't been a problem for me with any of the four PSII E2X models I have built and flown.
I just used regular 30 minute epoxy and it worked fine.

Click to expand...

Rex R said:

tis more of a possible problem with metal retainers than plastic, plastic doesn't conduct heat worth a darn, so by the time the epoxy gets soft you don't have a retainer.
Rex

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Bat-mite said:

I flew my Leviathan at URRF II five times. On the last flight, when I tried to unscrew the retainer knob, the entire thing (threaded part and all) came off. I used 5-minute epoxy. Some other problem, then?

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The biggest problem I've seem with folks using these retainers is that they forget to raise their rocket up and away from the blast plate. If it's too close the flame from the motor will melt it!

Jerome

5 minute epoxy is not 30 minute epoxy.

5 minute does not soak into paper tubes or through glassine coating as well as 30 minute.

5 minute gets soft and degrades after exposure to high heat and multiple cycles can weaken more and more until failure.

Which type do the instructions say to use?

The instructions aren't specific, it simply says "epoxy." I will go back and check the fine print. Since this is my first build on what is an introductory rocket, and i have not had a lot of experience with epoxy resins, it has been more of a learning experience for me. I fully expect that the next epoxy that I will be buying will be more of the 30 minute variety.

Granted, while the Prowler can use composite motors, it of course, recommends the E16 and F16 Estes BP motors to begin with. The fine print does say that the Composite motors can be used.

As a follow up, I picked up some 15 minute epoxy today to handle some home repair work, and I may use this for the retainer ring plus the shock cord mount.

We've been doing lots of housework lately, so not a lot of time to build or paint rockets.

I have to say the prowler does cut a sleek profile. I'm almost afraid to launch her, as on the weakest engines she's still likely to top 1000'.

Update, although no pictures yet. Shy of adding the self-stick decals the Prowler is ready to fly. I used the stock parachute, but a quick release and swivel from Top Flight Recovery. The recovery system is secured with 15min Epoxy, as is the motor retainer ring and the fillets for the fins. The supplied elastic is significantly longer than anything I've seen in a rocket kit before, but that's not a bad thing.

I've weighed it, and flight estimates on an E-16-6 put it around 850ft. I'd also like to fly it on an F26 or similar characteristics. I'll get the decals on and take some pictures.

As promised here's a pic of the completed rocket. Soon to follow will be it's maiden flight

Looks good! Can't wait to see its Maiden Voyage. Best of luck.

It's a nice looking rocket. Enjoy flying it!

Bat-mite said:

I flew my Leviathan at URRF II five times. On the last flight, when I tried to unscrew the retainer knob, the entire thing (threaded part and all) came off. I used 5-minute epoxy. Some other problem, then?

Click to expand...

You need something that is a lot more heat resistant like JB Weld. That is what I used on these and it worked great and holds the retainers on very securely.

I use/used 30 minute epoxy to attach the retaining ring to the motor mount tube of my Estes PSII models. Sanded the inside of the ring and outside of motor tube to rough up the surface.

All rings are still attached after my models have been flown on both black powder and composite motors.

In this case of this build, some of it is with 5 minute epoxy, and the rest is 15, particularly the engine retainer ring (complete with roughing up), as well as the fillets, and where I secured the elastic to the side of the tube. I'm not sure of other Pro II Series builds, but it is a plastic assembly that holds the elastic in place, rather than the 3-fold paper.

I realized after the fact that I didn't actually show videos of this one launching. It flies very well, and as I've found out, it must have a low coefficient of friction, partly due to the aerodynamics of the fins, plus the smooth finish on the body.

Here's the first two launch videos from last August:
On an Estes E16-6
[video=youtube;r_l0SoqYKMY]https://www.youtube.com/watch?v=r_l0SoqYKMY[/video]

An Aerotech F20-7W
[video=youtube;mS0XnINFzkI]https://www.youtube.com/watch?v=mS0XnINFzkI[/video]

And then just this past weekend, and on a much clearer day, on an Aerotech F27-8R
[video=youtube;ykrs90n3zxQ]https://www.youtube.com/watch?v=ykrs90n3zxQ[/video]

This has proven to be a reliable flier, if capable of some pretty decent altitudes on composite motors. As an introduction to Mid-Power rockets, I'm pretty happy with it so far.

Medium CA glue works great for holding the motor retainers in place.

John Boren