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Tweeting our Next Launch Day

This Sunday the 3rd April at approx 2:30pm Sydney time (GMT+10 or 04:30am 3/4/2011 UTC time) we will have a launch day to try the new updates on the water rocket car. We may even have a shot at the Dragster Speed Record if things go well.

We will try out something new for the hobby and use twitter to provide updates, commentary and photos in real time during the event.

Updates will be via our Twitter Page

If your a regular tweeter then you can go to our twitter page and follow us now then get our updates as we post them.

We will use the hashtag #waterrocketcar for all posts

If you are not a regular twitter user thats ok too, just go to our twitter page above about that time in your local area, or check out our HHWRSA web site (this site) and look in the sidebar to the right —-> under the Twitter heading and updates will be there too.

Here is a good time converter, remember our time is Sydney Australia Time, and no daylight savings tomorrow :)

Posted by on April 2nd, 2011 Comments Off

Rear Exhaust Deflector

One of the things we have noticed after raising the height of the rear of the car to give more ground clearance, is that it looks like some of the exhaust will be hitting the rear wheel supports.

While this may not impact speed or distance greatly, we have added a corrugated plastic deflector at the rear of the car to ensure the exhaust is deflected up and away from the rear wheel supports.

Rear Corrugated Plastic Deflector

The rear deflector is angled up towards the back of the car as can be seen from this picture. Yes the rear wheel attachments are not pretty but they are functional :)

Angled up exhaust deflector

This deflector is only really necessary due to too much  flex in the chassis. This caused us to raise the rear wheels to get the chassis of the ground, that then moved the rear wheel supports into the exhaust plume. So this deflector is a work around, but it will be interesting to see how it performs. It may also give us more downforce over the rear wheels which would improve stability.

The connection to the launcher still fits with the deflector in place and the female Gardena should just flick up over the top of the deflector as the car accelerates away after launch.

Posted by on April 2nd, 2011 Comments Off

Distance Marker Improvements

We noticed that the lines we marked with chalk on the asphalt road didnt come out very well on the onboard video from the last launch day. So we have taken 3 additional steps toimprove this for our upcoming record attempt.

1 – We are using plasterboard (gypsum board, gyprock, drywall etc) which is approx 12mm thick (1/2″) to draw the lines, this is about twice as thick as our previous chalk and initial tests show the lines a lot clearer.

2 – We will put coloured markers on the side of the road at each 10m mark (line).  Each 10m mark will get a “RED” marker and each 50m will be a “BLUE” marker.  We will put a “GREEN” marker at the 150′ mark (45.7m) (for the speed record distance)

3 – We are installing a second camera on the car to look sideways with the front wheel in shot to capture the markers on the video as the car passes them.

A big thanks  for some inspired thinking goes to Lisa  and Spaceman Spiff from The Water Rocket Achievement World Record Association for the  coloured marker ideas.

The markers we will be using will be plastic coloured cups / tumblers, another great idea from Spaceman Spiff, which will save space in the transport vehicle getting to the launch site. We have the biggest, brightest ones we could find so that the cups are still visible even if there is a bit of a  crown in the road.

The ones we chose are 12.5cm (5″) high and have a very vibrant colour. They will also take up to 550ml of water so once in place and full of water they wont blow over.

Here is a quick picture of the cups we will be using

Coloured Distance Markers

Here is a comparison to a normal size plastic cup …

Comparison to normal cup ~220ml

With these three improvements in place the video should clearly show the car passing the marks every 10m from which the cars speed can be calculated and the distance can be validated.

Posted by on March 10th, 2011 Comments Off

MD80 Camera

The water rocket community is using these MD80 clone cameras more and more as they are cheap, light and provide good video. We decided to replace our heavy onboard  camera with this camera.

MD80 clone camera

Initial tests showed the video quality was quite good and much better than the cigarette lighter camera we tried. We mounted this camera on our water rocket car for our recent test day. The camera can be seen in this launch picture.

MD80 Camera attached to car

We had an issues that one of the launch videos was overwritten when we got home to download the videos, so on advice from other water rocket users of this camera we will need to download the videos off the camera after every launch.  This means we need to take the laptop and a USB cable to the launches to download the videos.

We decided also to mount the camera further back on the car to get a better chance of seeing markers on the road. Here is where we mounted it on the rear guide rail lug support.

MD80 mounted on the water rocket car

This location gives easy access to the underside where the USB cable attaches, as well as not interfering with the on/off switch and the start/stop button of the camera. We can also charge it on the bench in the garage of we need to with a USB cable to a power adapter. Here is the USB cable attached to the car

Camera attached to laptop and downloading video

This  position mounting the camera further back  provides a good view of the water rocket car as well as the ground and the front wheels. This is a shot from the camera mounted in that location.

Video grab from new mounting location

Posted by on February 14th, 2011 3 Comments