Sunday, February 14, 2016

2 stage water rocket and single stage QRS Feb launch

Feb update on 2 stage Water Rocket
Had some success with bugwubber clamp working and radial deploy success.
Very low altitude on second stage launch. Drogue was supposed to pull a main chute out but failed.
Second stage chute failed to deploy. Not sure why. Second stage suffered fatal damage.
Hoping to complete a new rocket with drop away boosters and a second stage on top for the April QRS launch.

Then had fun with single stage rockets made from 70mm WATER bottles (not Soda).
Nice straight flights except the first one snapped off the chute but amazingly it glided back to the ground without any damage.. Lucky day.

Next 2 launches went fine.

Thursday, February 4, 2016

Update to 2 stage rocket

After a failure with a 2 stage rocket launch last month, I have modified the clamp system with extensions. The previous failures were caused by the sleeve distorting under pressure and allowing the clamp to release. The extensions are designed to clamp to the upper stage which has a firm shape and should not allow the clamp to release prematurely... Here's hoping.

A link to last months failure is here. (about half way through)

Saturday, January 9, 2016

January Trials

Had a great day out with QRS. Managed a total of 3 flights with one disaster.

A 2 stage rocket I'd been working on for a while had a second stage launch on the pad. This destroyed the payload area, timer etc.
Seems the radial deploy wasn't strong enough to handle the pressure. It blew at 85psi.
So it's back to the drawing board for that project.

2 other flights using 70 mm water bottles (not soda) both flew well at minimum pressures around 90psi.

Noticed the O-ring on the gardena nozzle had slipped up the nozzle on 2 launches. Suspect this is reason for sudden/temporary loss of pressure when getting rocket ready. Will change 0-rings and try different nozzle brand.

Anyway, here's a quick look at the day.

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.