2 Stage FTC Water Rocket

This is most certainly a project we wanted to do for a while, a multistage water rocket with a FTC sustainer. While designing the rocket, I thought about one of the major unknowns, how much the sustainer will bend during the acceleration phase of the flight. We will probably use a small nozzle for the sustainer around 9 or even 7mm. While doing a bit of research, I discovered that one of the first water rockets to break 1000' was a multistage water rocket with a FTC sustainer and a PET bottle booster. This is very convincing. We test fitted a test rocket together to get an idea on how tall the rocket was going to be.

Yes, the ladder is going to be needed to help set-up the rocket! It stands about 14 feet tall without the parachute deployment system(still yet to be designed). We are likely to use a 15 or 16mm nozzle for the booster and 9mm for the sustainer. For the stager, we are likely to use AirCommand's MK3 stager. The Capacity of the whole rocket is likely to start out at around 7 liters(4 liter booster, 3 liter sustainer), and increase the booster capacity later on. The initial launch pressure is likely to be around 100 psi, although we may bring it up to around 130PSI later on. After this project, we will likely start up the fiberglass rocket again.

11/28/13

Today we glued the fins to the sustainer with PL Prenium.

I just eye-balled the fin allighment so I'm taking a chance of the fins being off. We did a rough simulation of the rocket on Cliffard's Health simluator. It predicts around 900' at 100psi. This calculation is pretty sketchy because we don't know the weight or final volume of the rocket. It's also hard to enter the two diamaters of the booster and the sustainer, so the altitude could be a lot less.

12/22/13- FTC Rocket's Parachute Deployment System

Today we designed the parachute deployment system for the FTC sustainer. The system is very similar to the one shown here: http://www.wra2.org/forum/viewtopic.php?f=5&t=2217

The main difference is that the coriflute plastic was replaced with a plywood base.

 That does add a little more weight, but is more stronger. In total the system weighs

56 grams. 

We have tested the system many times, a 9/10 

Successful deployment. The one time the deployment system 

Failed is when the rubber band didn't come off of

The timer's spindle. A little silicone grease fixed

it up. I also did a quick seal check of the rocket to 75

PSI. I decided that we are going to fly the rocket as a single

stage first to test the deployment system this week.

Projects Update

Over the past months I've been busy with school and other non-water rocket projects, so I haven't had too much time to write in this blog. So here is a update of what we've been up to other than the normal water rocket flight days.

      FIBERGLASS ROCKET

 Since the last explosion of the fiberglass reinforced rocket, dad and I have been pondering weather or not to rebuild it. We've decided not to rebuild it, but to make a all fiberglass rocket. We chose that so we could directly control it's property's and hopefully make it able to withstand at least 400psi. Many of the building Technics are browwed from the model rocketry world and AircommandWaterrocket's Shadow build log. We are planning to use a 15mm brass nozzle. Overall the rocket will have a Capacity of about 4 liters.

Yesterday we made a small test roll of fiberglass to see how easy it would slide off of the 60mm PVC pipe and Glad freezer paper. Thankfully it slid off easily. We decided to make 2 test end caps to pressure test the tube. We glued the 2 endcaps to a 4inch long pvc pipe and glued the end caps to the fiberglass tube with PL Premium. We let it cure for 4 days before we pressure tested it yesterday. Thankfully it held up to 570PSI before bursting. It was loud even though it was in a old scuba cylinder and had pellows on top of it. That's the good thing about living in the country so we don't have neighbors complain! 

We went ahead and made 3X4 foot tubes today and let them cute for a few hours. We then coupled them together using PL premium. We then added another layer of Fiberglass bringing it to a total of 6 layers. The coupler is made out of 4 inch long PVC pipe. I found a 15mm nozzle in my 'junk' box. Ill use this for the nozzle. I cut a hole for the nozzle in a end cap then epoxied it in with 24 hour epoxy. I then glued it on to a peice of PVC pipe and glued that to the fiberglass tubes. Stay tuned to see more progress of the fiberglass rocket. Here are a few pictures:

11/18/13 Today we pressure tested the rocket today to 400Psi before the middle section sprang a leak. We let the rocket pressure drop down to around 50psi before we went to look. The tube cracked about a inch above the coupler. Sadly we are going to put this project aside to work on a Diffrent one we wanted to complete this year.