Greetings

[BigGuy2004]

Greetings,

My name is Ellis Stewart, and my wife, Mary, and I reside in rural Eau Claire, Wisconsin. We are semiretired and have two grandsons ages 7 and 9. We became interested in water rocketry last year and during the winter we built a launch pad and launch control panel using pneumatic controls for our grandsons. We launched our first rockets in April, and more last weekend. Our system works well, and is quite safe for our grandsons. Our largest rocket to date is an 8 liter one that we plan to launch this coming weekend. We are experimenting with fins made of both Corroflute and 3mm Baltic birch plywood. Our biggest challenge at this point is selecting a recovery parachute approach, acquiring the components, and adding to our rockets. Like others, we have followed George Katz and his family on their Aircommand Water Rocket website. George and I have also shared info about our launch system and rocket construction fixtures. I am very impressed with the Parachute Deployment System shown on U.S. Water Rockets.com, and I expect we'll use that approach. We are looking forward to learning and sharing with many folks on this forum. Best Regards,

[Jamie5335]

Hello There,

Glad to have you on the forum, from what you have said it sounds as if you are pretty well experienced in Water Rocketry and I look forward to your contributions to the forum! I myself was thinking of making some Balsa fins instead of Corflute as they tend to get dirt and all sorts of grit in them- so let me know how you get on this weekend. Do you use a Ballistic Approach to recovery at the present or does your rocket back-glide down? Your launcher sounds interesting as well. Some pictures would be great!

Good Luck for the Future,
Cheers, Jamie B.

[BigGuy2004]

Hi Jamie,

Thanks for your reply. Attached is an image of our launch system. You'll note our rockets are primitive at this point. We just finished an 8 liter rocket and are now "decorating" it for launch later this month when our grandsons are out of school. Our recovery system is TBA, and I think we'll use the radial deployment system found on USWaterRockets.com. For now, we grit out teeth and prepare for crash landings. Although we made a small 3 liter rocket that has withstood a dozen launches and crash landings and keeps on ticking. We used 1/8" foam board for the fins, and they finally failed. We'll replace them with Corroflute. We have not yet used our Baltic Birch fins. They are more dense than Corroflute, and will certainly affect the center of gravity. We use four clipped delta fins based on a design in the "Handbook of Model Rocketry" by the Stines, and they assure our center of pressure is well toward the nozzle. That's it for now. Thanks again.

Ellis J. Stewart
Eau Claire, Wisconsin

[bugwubber]

Hi Jamie,

Thanks for your reply. Attached is an image of our launch system. You'll note our rockets are primitive at this point. We just finished an 8 liter rocket and are now "decorating" it for launch later this month when our grandsons are out of school. Our recovery system is TBA, and I think we'll use the radial deployment system found on USWaterRockets.com. For now, we grit out teeth and prepare for crash landings. Although we made a small 3 liter rocket that has withstood a dozen launches and crash landings and keeps on ticking. We used 1/8" foam board for the fins, and they finally failed. We'll replace them with Corroflute. We have not yet used our Baltic Birch fins. They are more dense than Corroflute, and will certainly affect the center of gravity. We use four clipped delta fins based on a design in the "Handbook of Model Rocketry" by the Stines, and they assure our center of pressure is well toward the nozzle. That's it for now. Thanks again.

Ellis J. Stewart
Eau Claire, Wisconsin

Wow! Howdy neighbor!

[BigGuy2004]

Good Morning Bugwubber,

Thanks. How are things in Zimmerman?



Ellis J. Stewart

[bugwubber]

Good Morning Bugwubber,

Thanks. How are things in Zimmerman?



Ellis J. Stewart

Summer just started, the strawberries are blooming like crazy and the weather is just...perfect. Time to go camping with the family.

[Jamie5335]

Hello Ellis,

You launcher looks professional considering you are starting this hobby and I look forward to your future posts!

Good Luck with your new 8 liter rocket, have you Spliced bottles together to achieve that volume or have you used a Robinson Coupling? It would be interesting to know your opinions/methods on either technique.

As a matter of fact I am going to replace my 3 Corroflute fins with some more sturdy Balsa fins and I find that even under chute the rocket can come down pretty quickly and because we launch in a farmers field they can get pretty battered and dirty! Though Corflute is an excellent building resource for water rockets mainly because it is very light.

Cheers, Jamie B.

[BigGuy2004]

Hi Jamie,

Thanks for your feedback on the launcher. I understand about the issue with Coroflute/Coroplast getting dirty. All the tubes are like dirt traps. For what it's worth, we applied 1/2" wide plastic tape the the leading edges and the tips on the fins on our 8 liter rocket before we painted it. An image is attached for your review. We'll see how well it works later this month.

The bottles on the 8 liter version are joined using Robinson Couplings. Then we add fairings bonded with Loctite PL Premium construction adhesive. I made a fixture of 2-1/2 inch aluminum angle to help ensure the rocket is straight as the adhesive cures. We use rubber bands to hold the rocket snugly to the aluminum angle. Works pretty nicely so far.

I intend to learn to splice bottles as we build ever larger rockets. The Robinson Coupling restricts the water flow since their inside diameter is smaller than the 9 mm diameter of our Gardena nozzles. We'll see that effect on the 8 liter rocket since we'll be filling it with 2.4 liters of water.

I have on order the components to build the Radial Parachute Deployment System found on USWaterRockets.com.

I'm also thinking of purchasing some sheet stock of clear polyester film around 0.007" thick to make fairings and such. It might work better than spicing bottles to make long fairings. Still noodling on that one.

That's if for now.

Best Regards,

Ellis J. Stewart

[Jamie5335]

Hello Ellis,

Wow, that is a nifty looking rocket you've got their! I can't wait for a launch video! I myself have never tried Robinson Couplings as I just skipped to Splicing but I would like to give the Couplings a go as they help with jet foaming.

I might just try that tip with the fins, I have tried plastic straws but they just get shredded! Always good to make sure rockets cure nice and straight, I put the bottles on a rotisserie and you can then clearly see if any of the bottles are misaligned when the glue is curing.

The radial deployment system is an excellent choice for a release system, what Flight Computer are you using- got to be my favourite part as I like to design my own!

And the ideas for your fairings are pretty neat, I just tend to use a different type of bottle with no ridges but I might just try that and give some feedback.

Sorry for delay in reply, I had a few exams!

Cheers, Jamie B.

[BigGuy2004]

Hi Jamie,

Nice to get your reply. I'm pleased to get your feedback about the parachute deployment system. Right now we are waiting for delivery of the batteries and one of the wiring devices. The microcontroller we are using is the TI MSP430 LaunchPad Value Line Development kit. At this point designing our own is beyond our scope. I suspect we'll get to that for next summer's projects.

As for the Robinson Coupling we made ours with a 1/8" diameter x 1" long brass lamp coupling, two rubber washers, two 10mm SST washers and two 1/8" hex nuts. Sometimes we use the coupling to fasten two bottles together bottom-to-bottom. Other times we use them to fasten a bottle cap to the bottom of another bottle. The slickest tools for making them include a 10mm twist drill, a countersink to deburr the drilled holes, and two 1/4" drive socket extensions and two 1/2" sockets. We also make bottle connectors by bonding two caps together top-to-top inside a 1" length of T-8 fluorescent tube cover and then drilling a 10mm hole through the caps. We do not use bottle caps without an integral gasket. The caps on some bottles have a mechanical seal and they are a problem. I think we find those on Dr. Pepper.

Thanks again for your recent message, and be well.

Best Regards,

Ellis J. Stewart