Sunday, 26 August 2012

Sunday August 26:

Today I did launched some of my rockets. I was happy with yesterdays result as it flew in a bow. The only thing I had to improve was being able to let it fly straight instead of in a bow as if when it flies in a bow the parachute will not deploy. From yesterdays results I also learned that I will have to make the nosecones diameter smaller so it fits harder on the top of the coke bottle. This may sound odd but I think if the nose cone doesn't fit as well it will be more likely it falls in mid air, which makes the parachute more likely to deploy.

I brought a piece of paper and a note pad, a pencil, my 3 rockets, 6L of water, a hammer to peg the launcher in the ground, the launcher it self, my ipod which would measure the angle from a certain distance which would allow me to measure the height it travelled, a 20m wire, a watering can, a measuring cylinder, glue if something would need to be fixed, tape for same reason of glue, a stick for when it would land in a tree and my camera where I could film the rockets performance. Note all early models of rockets are from france bottles not english, english coke bottles  have different shapes.

The test I did today were comparing some different diameters of nose cones and then seeing which one is the best for which bottle, in the sense that t falls of and let the parachute do its job. The two sizes i used were either 1.5L bottles or 2.0L bottle. Here are the results:

Test 1: Vertical take off, ballistic, landing 30 meters from land paunch pad. Used medium cone for a 1.5L bottle, pressurised a default pressure of 4.5 bar. All rockets will be filled with 0.5L.

Test 2: Ballistic, friction due to parachute wires sticking out from under nosecone which led to early deployment, however a perfect landing occured. This is a repetition of test 1.

Test 3: Use of smaller cone, vertical take off, ballistic, bottle 1.5L, pressure of 4.5 bar and 0.5L of water.

Test 4: Repetition of last test although this time with 6 bar however the nose cone was fixed from last night and wasn't able to hold 6 bar so we launched from 5 bar as we didn't want to break the nozzle. Ballistic and perfect parachute deployment.

Test 5: Use of 2L rocket with medium nose cone, again 4.5 bar. It had a beautiful deployment and it went fairly high, estimate of 50 meters.

Test 6: Repetition of last test, same results occurred.

Test 7: This time we decided to add more water and see what effect that would give.  4.5 bar and 0.75L. It didn't go as high so we decided 0.5L was better for this rocket.

Test 8: This time we added equal water as last test but increased pressure to 5 bar. It went fairly high but we got a slightly early separation of parachute.

Test 9: We used other 2L bottle but this time from England. This bottle was smoother. We pressured it to 4.5 bar and 0.5L and launched it with different nozzle as the cap is different. This was also ballistic and went up in the air, nice deployment of parachute occurred.

From these test we learned that the small cone can be used for the 1.5L and french 2L bottle and the medium cone for english one. We learned that adding wait in the cone also isn't necessary as that caused it to go in a bow while if you don't it goes straight up. Adding more water also didn't work as well and the results showed that 0.5L of water were perfect for these rockets. Lastly the test also showed that the parachute deployment now works perfectly.


Saturday, 21 July 2012

Saturday July 21:

Today I tested the new nozzle which again didn't want to screw on, I tried to file the bottom even more so it would be even thinner and not mess with the thread but still it wasn't thin enough and thus water still went out of the bottle. Then I had the idea of glueing it to the bottle but then I had to make so many nozzles and I think there must be another way. 

Tuesday, 17 July 2012

Tuesday July 17:

Today I tested the cap I made the other day using a soap lid and then putting a gardena threaded tap through it. I tested this by putting water in the bottle and seeing if it would leak. Unfortunately it leaked and so I tried to solve this problem by wrapping Teflon tape around the bottles thread which would make it water tight. Rapping it around the bottle took quite a while as you had to experiment with how much you would put on the thread, and you can only use it once. Unfortunately it can only hold for 3.2 bar and then the water is able to go through. This might be because I used a different thread then the bottle, so I decided to make yet another nozzle using a Coke bottles cap.

Here you have all the nozzles made: Note the red one is the new one.


Sunday, 15 July 2012

Sunday July 15:

Today I tested the nozzle I made the other day. Unfortunately it doesn't want to screw up on the bottle. The problem is that the gardena threaded tap is to thick so the bottle cant screw down enough. So I will make a new one but this time I will sand the bottom more so the cap can actually screw on the bottle. Although this time I chose to use another cap from a soap bottle as those are bigger and already have a hole in them for the pump mechanism where the soap comes out of. This cap should be easier to screw on thus solving the initial problem of not being able to screw it on.

Here is the new cap compared to the old one, as you can see the white one is much bigger then the old green one.





Saturday, 14 July 2012

Saturday July 14:

Today I tried to connect the pump to the gardena hose so I coudld start pressuring the PET bottles. I used a cork and a bike valve and a lot of glue to make it water tight, I also rapped some tape around the construction after it to make it even stronger.

I started by making a hole in the the cork on one side of the diameter of a gardena hose and then a really small hole in the other side where a bike valve would fit it. Then I would glue the bike valve in the small hole and the gardena hose in the other one as shown in the diagram below. 


Friday, 13 July 2012

Friday July 13:

Today I got my first PET bottle and thus I could start the actual project. Today I started making the nozzle. So I started by taking a gardena thread tap connector and tried to screw it on the bottle. Unfortunately The gardena thread tap connector had a different thread then that of the bottle thus they wouldn’t connect. Luckily I researched this before and saw a good solution to this. I had to drill a whole in a cap of a bottle and then take a gardena thread tap connector and saw of the thread. Then I would glue the gardena thread tap connector on the inside of the cap.

Here are some pictures showing the steps I did:

Step 1: Saw of the thread of the connector:

















Step 2: drill a whole in the cap and then glue them together:


Thursday, 12 July 2012

Thursday July 12:

Today me and my family went to the store for foods and materials. We bought everything that was from the list plus some other things that might be useful. This took most of my time and I cant really start until I have a Coke bottle in my possession. Thus I just looked at some other peoples videos on Youtube and saw how they did it.