Wednesday, December 30, 2015

Making a bottle connector

After a couple of mishaps with glued caps inside pvc tube, i decided to make a stronger connector.
The PVC tube has a series of holes drilled around them.


The caps are then glued in using plastic glue.

A soldering iron is used to 'Scrap' the cap's plastic up against the edge of the hole, locking the cap in place. The holes are then filled with epoxy. If the soldering iron burns right through just scrape some pvc back in. Rough is OK. There just needs to be some locking in. Please wear a mask or do in the open air.


The tubes are then sanded down to remove excess epoxy and a 16mm hole drilled in. Use a flat wood bit. It's easier to find centre and they cut the cap seals with a clean edge.

I haven't had one of these fail yet....


Saturday, December 19, 2015

2 stage rocket live test

Thought I'd better test this out before flying. Hand held the elastic band holding the cover down and pumped it up to just 30psi. Seems to work fine. Another bottle in the neighbours yard. Bit nervous about higher pressures. Will make a couple more variations on the idea so there's a Plan B on launch day.

After some sage advice from Air Command, i have decided to remake the whole system again without a non-return valve and just a small hole in the tube which will act as a pressure safety vent if launch is aborted. Thanks for the idea George.

here's vid of the test. Launching for real in January when i get back from Chrissy holidays.
Clear skies to all.


Friday, December 18, 2015

2 stage rocket set up

Finally got all the bits made for this rocket. It's based on the Bugwubber design and US water Rockets video. Not flown yet. Just a set up in my house.

The parts are all wood and fiberglass. Even the dowels are bamboo skewers. Yep they can take a lot of shear force.
The main stage is 90mm 1.25L approx 4L and the top a splice of 70mm. approx1.8L total.
There will be 2 tiny parachute to pack either side of the clamp section. I hope it's enough to bring it down safely.
Doubt it will take much pressure (maybe 80psi, but a real test will tell.
Probably need to remake clamp from kevlar or aluminium?
The second stage chute deployment is based on RaketfuedRockets idea. Thanks to all the community who share these fun concepts. Was a complex build and hope it doesn't get destroyed on first launch.



Tuesday, December 15, 2015

non-return valve for a water rocket

I was looking for a simple non-return valve for a water rocket when building a multi-stage system.
Needed to be cheap, easy and repairable. Designed to go with the BUGWUBBER clamp idea. See staging post.

Multi-staging water rockets

Started looking at multistage rockets and found a great thread on Water Rocket Forum as well as a vid by US water Rockets. The mechanism reverse engineered by BUGWUBBER is wonderful.
Below is my first drawing idea.

See my non return blog for further developments.


Water rocket with Santa Claus

The Loony Lander idea I had recently, was used to make a rocket that launched Santa at Apogee(ish) and he descends on his own parachute.

Also made a big cardbord box chimney in the faint (fat) chance he might land in it..
Launching this idea at Queensland Rocketry Site this Sunday coming.
The theme for the launch day is of course Christmas...

Check out more at Aus Rocketry Forum:
http://ausrocketry.com/forum

Monday, December 7, 2015

Loony Lander

The recent Martian film inspired me to try building a lander.
The lander separates from the rocket at apogee. The legs then fold out and a parachute is released. 
The rocket comes down on its own parachute and lands on independent suspension (elastic bands).
Tomy timers and elastic bands control all actions.  The lander releaase is controlled by inertia. Thanks to George from Aircommand for that idea.
Pics attached are prototypes. Legs that where made of balsa broke, so made from lightweight ply.

Chance of success: <3
Intend to launch early November (cancelled - now January).
Crash results and damage report will be posted on Youtube.
cheers

Test flight of Water Rocket Dual Boosters

Had fun on Sunday launching a test water rocket with dual drop away dual boosters.
Forgot a pressure gauge so had to guess on main rocket. Suspect we were only at 60-70psi.. Booster with 20mm nozzles at just 40-50psi by hand pump. Main rocket with 9mm nozzle. No metal components are used at all. Used irrigation tubes and bamboo skewers (with points cut off) to join.

Boosters are just single 1.25mm bottles. Tommy timer for deployment on this test.
First launch, boosters failed to separate. Second launch went fine. 

Back home to do a lot of modifications...

Will launch with much larger main stage next time, foam in main rocket and higher pressures etc. Just happy it worked at all.  Sorry about footage but had issues driving cameras, pumping things up and launching at same time.