The Shadow - Launcher video

With Christmas celebrations mostly over, dad and I put together a short video today that describes how the Shadow's launcher works and how the rocket is loaded onto the launcher. I've added the video to the latest Shadow update here:

http://www.aircommandrockets.com/shadow.htm#_171211

Other than that there really hasn't been much happening with all the lead up to the holidays. I've added a few links to Facebook and Google+ from our main website. These will be updated regularly with latest developments as well so if you prefer to receive updates that way or just want to chat about rockets then those should make it easier.

Here is The Shadow with a fresh coat of paint:

Merry Christmas!!!

We all know we want one of these for Christmas

We wish you and your family all the best for Christmas and also into the new year!

Unfortunately we've run out of time to launch The Shadow this year, but we should get a chance to launch it at the next NSWRA launch in January. The quiet time over Christmas should allow us to also complete a couple of other projects that we've been working on. I'll post more on those when done.

Now where is my helmet? ... I'm pretty sure I saw a rocket sled sized box under the tree.....

The Shadow - coming together

We've been flat out over the last couple of weeks, but have had time to work a little on the Shadow. We've now finished the launcher, and the fins are now also attached to the rocket. The nosecone and payload bay have been painted which will make them easier to find should they separate from the rocket.

In the next week or so we should have the rest of the payload bay complete with the camera, altimeter and batteries still to be mounted. The rocket at least is now starting to look like a real rocket. :)

I've update the build log with a few pictures from the last couple of weeks.
http://www.aircommandrockets.com/shadow.htm#_061211

Reefing Parachutes

This weekend we went down to the local park to fly a pair of smaller rockets to test a couple of techniques for reefing a parachute to stop it opening too quickly during high speed deploys. The first technique used the old reefing ring approach and for the second experiment we simply twisted the shroud lines. We managed to fit in a total of 6 flights before the wind picked up.

We’ve written up the results from the experiments here:

http://www.AirCommandRockets.com/day114.htm

The update includes a video that shows how the reefing works in flight.

 Reefing ring preventing the parachute from opening too quickly.

Simple break-wire trigger

We've had a number of requests now for how to add an external trigger to the Servo Timer II for the very slow launches that the built-in G-switch may have trouble detecting. I've added a tutorial on how to add a simple break-wire option to trigger the timer on launch. In most instances it should not cost anything.

http://www.aircommandrockets.com/servo_timer_V2_0.htm#_tip5

Shadow pressure test, and deployment mechanism

We have been making good progress on the Shadow. During the week we tested the deployment mechanism and made a short video of how it works.

Today we pressure tested the launcher and rocket to the full initial launch pressure. This was the first time we had the rocket and launcher up to this pressure, so we were happy when everything worked. We even tried to see how hard it will be to launch the rocket at the full pressure. This was nice and easy and shouldn't be an issue on launch day.

 
The recent updates from the last week have been posted to our main website with photos here:
 http://www.aircommandrockets.com/shadow.htm#_171111

The update also includes the deployment mechanism video.

Alternative Fuels

This weekend we flew with some “alternative” fuels in our water rockets. OK so technically they weren’t “water” rockets, but hey still it was a bit of fun with the kids. From a scientific point of view it was interesting to see how these fuels behaved.

Fuels Tested:
    - Bread crumbs (dry)
    - 100’s and 1000’s (dry)
    - Sugar (dry) - the other kind of “Candy” motor :)
    - 2 minute noodles (cooked and in broth)

So how did they go? … read on:

http://www.AirCommandRockets.com/day113.htm

 

Shadow Launcher work

We’ve had a busy week in the workshop working on the Shadow. We’ve been mostly focusing on getting the launcher complete, so we can pressure test it and the rocket. We want to test the pressure chamber before we attach the payload bay and fins, because if it bursts, it would be wasted effort. However, we can only test the pressure chamber with the launcher.

The latest set of updates with photos is available here:
http://www.aircommandrockets.com/shadow.htm#_061111


Here is a progress photo of the launcher release mechanism. This launcher is being built for 500+ psi pressures.

11/11/11

This post has no purpose other than being posted at 11:11:11 on 11/11/11 .... Happy Binary Day. :)

From The Web #1

As you trawl through the interwebs, you often find interesting things that are relevant to water rockets. As I collect these, I'll try to post them here.

• Rocket Electronics Info
  Although this covers mostly pyro rocket electronics, there are many good bits of information relevant to water rockets, especially the altimeters section.
  http://www.rocstock.org/wizards/rocket.electronics101.pdf

• Build Your Own Servo Controller
  Here is a tiny PICAXE-08M board that's very affordable and should be fairly easy to adapt to make a simple servo controller for parachute deployment.
  http://www.hvwtech.com/products_view.asp?ProductID=1056
  You could do all your configuration through it's serial port so there would be need for only minimal external components. You could also solder one of those small Assemtech G-switches directly to the board to detect launch.

• PL Premium in Oz
  Water rocketeer Voytek Szapirko contacted us last month with the news that he was able to find PL Premium for sale at his local hardware store Bowens in Melbourne/Hallam for $6.99 a tube.Thanks for the tip Voytek! :) If you are from Victoria keep a look out at your store. We don't have the chain here in NSW, but hopefully other stores here will catch on with the need for PL.
  
• Retro Water Rockets from 1959
  Apparently you need to wear a tie to launch these: http://books.google.com.au/books?id=KdwDAAAAMBAJ&lpg=PA54&pg=PA94#v=onepage&q&f=false

Looking Up

I've uploaded the flight report from last weekend to our main website here:
http://www.AirCommandRockets.com/day112.htm
On this flight day we flew with the out-rigger boom again but this time looking up at the rocket to watch the parachute deploy mechanism in action. The update also contains photos and a highlights video from the day.

Migrating Videos to New YouTube channel

As we did a couple of years ago with the website, we’ve finally decided to bite the bullet and start migrating all the videos from the current YouTube channel to a specific Air Command Water Rockets Channel. I’ve been wanting to do this for quite a while since the existing channel was only ever a temporary one. With the normal slow down over the Christmas period, it will be a good opportunity to do so. We have a number of videos spread across Vimeo, MySpace, YouTube and several other hosts so we will consolidate all these into the single channel. It will be easier to make up playlists of related videos and keep them all organised, especially as they relate to each project. I’m also hoping to upgrade the YouTube channel so we can provide extra features.

The biggest drawback is that the comments from people will be lost, links to the videos will be broken, but if I don’t do the migration now, it would just get worse into the future. I am backing up the comments though. Expect videos to start disappearing over the coming weeks/months from our current channel, and they will be re-uploaded to the new channel over time. I will also update the links to the video from our website, or where I can.

Some of the older videos were also uploaded only in lower resolution, so where I can I will re-compress these again at higher resolution before uploading.

If you have been subscribed to our youtube http://www.youtube.com/user/gk123434534 channel and wish to continue receiving subscription updates please subscribe to our new channel here:

http://www.youtube.com/user/AirCommandRockets

All new videos from now on will also be uploaded to the new channel.

Thanks everyone for your support

Rockets - Dawn 'til dusk

We had a very busy rocket day yesterday with our regular NSWRA launch at Doonside from early morning until noon, and then in the evening we had our NSWRA display at the Macquarie University Astronomy open night. We had lots and lots of people come up and ask questions about rocketry, and I'm sure there will be a few people that will come to the launches as a result of it. I'd say close to a couple of hundred people came to look at the display and have a chat. We had the G2 on display as well. I didn't get home until after 11:30pm last night.

I'll write up a full flight report and info about the Uni display in the next few days.

NSWRA at Mac Uni Astronomy Open Night

NSWRA (NSW Rocketry Association) is going to have a stall at the Macquarie University Astronomy Open Night this weekend Saturday October 29th from 6:30pm. If you want to find out more about rocketry and haven't had a chance to come to one of our NSWRA launches at Doonside, then why not stop by and have a chat.

There will be a number of NSWRA members to talk to. We'll be there as well for a part of the night.

Find out more here:
http://www.nswrocketry.org.au/PublicPages/Public_Mac_Uni_Open_Night.html

So how big is The Shadow?

Now that we have most of the components made, we are in the process of assembling them into the actual rocket. Here is a picture of the pressure chamber with payload bay and nosecone fitted on top. The entire rocket is 2580mm tall (~8.5 feet).

 I've added some more progress photos from the last week of construction here:
http://www.aircommandrockets.com/shadow.htm#_151011

There is still lots to do on this rocket, but it's good to see it finally in context so that we can finish designing the launcher and figure out how we fill it with water and launch it. We're hoping to assemble the pressure chamber over the next week and pressure test it. For the pressure test we are going to need to finish the launcher, as it will be the only thing that will seal against the nozzle.

Otherwise progress on other projects is on the back burner for now as my regular daytime work has been extra busy lately.

Shadow progress update

We've been busy this week making good progress on The Shadow. We now have a new set of fin guides that will be used to align the fins. We made a new coupler mandrel and have made a number of fiberglass couplers for joining tubes. We also started working on the business end of the rocket today and machined the nozzle and the nozzle seat it will sit on. We are having to build a completely new launcher for this rocket to handle the higher pressures.

Updates from the last several days are here:
http://www.aircommandrockets.com/shadow.htm#_270911

(NOTE: You may need to refresh the page as sometimes it gets cached and you won't see the updates.)

Nozzle seat and nozzle

 Fin guides to align fins

Casual flights

While we still work on the bigger rockets, we took the opportunity last weekend to do a few casual flights at the NSWRA launch day. It's always nice to get out and launch a few without having to do a lot of preparation. These rockets were quickly assembled from the set of spare parts we have on hand. We flew the HD camera again on all the flights.

Here is the update: http://www.AirCommandRockets.com/day111.htm

Panorama taken from the last flight

The Shadow

Rocket build progress has been continuing at a good pace. We currently have a number of concurrent builds under way. These include the Acceleron V high pressure sustainer upgrade, the Polaron G2 phase 2 booster development and our newest project called "The Shadow".

We have actually been working on The Shadow for a number of months, but hadn't published details about it yet, though we have been taking pictures and keeping a build log of the rocket development. We have now uploaded the build log to our website so you too can follow along with the development. So far it's been an interesting project to work on and has consumed perhaps 60% of our build time.

The project now has its own build page rather than scattering bits of information about it in the various flight log updates. We'll keep the page updated as we go and post the flight reports in the regular updates.

http://www.AirCommandRockets.com/shadow.htm

Side Deployment Parachute Mechanism Tutorial

It's been a while since the last update, but rocket development has continued. We are currently working on the G2 boosters and have been doing a number of tests. We’ve also been building up our spliced bottle stock pile and spare deployment mechanisms for our rockets. It’s always good to have both components on hand so that we can assemble rockets quickly and have spares when they crash. While making the spare nosecones we took some time to document how we build them.  

The new side deployment mechanism tutorial is mostly based on our previous version. This one incorporates a couple of improvements we’ve been using for a while that makes them easier to build and more reliable.

And a big thank you also goes to Doug from Escape Water Rockets for helping us source some components for the Servo Timer II when the local supplier ran out and was going to take a couple of months to get them back in stock. 

G2 - Phase 2 Development

We have been continuing to do further development on the G2 rocket. This week we did a number of static tests with the G2 main stage to see what amount of thrust it will produce and what the thrust duration will be.  The rocket was connected to the load cell so we could measure the thrust accurately. We are looking for a nice long burn with this rocket and managed to get about 10.5 - 11 second long burn. :)

The full progress report is here:  http://www.AirCommandRockets.com/day110.htm

G2 launch report

I've updated the main website with the launch report from this weekend. The update includes photos and a highlights video from the two G2 flights we did on the day.

The update is here: http://www.AirCommandRockets.com/day109.htm

I'll soon be posting build progress updates as we get rolling on phase 2 of the G2 project.

Right, time to get back to the workshop...

More Polaron G2 flights

After a short break from building water rockets to catch up on a number of other projects, we decided to take the Polaron G2 for an airing again. The launch conditions were great today with blue skies and virtually no wind. The rocket configuration was identical to the previous flight. We launched the rocket twice, once at 230psi and once at 240psi. The rocket performed really well with good deploys just past apogee and both the primary and backup parachutes opening right on cue on both flights. 

Turning on electronics prior to pressurising.
Paul at the ready to arm and launch the rocket.

We'll do a full write up with more photos and video on our main website in the next few days.

Pan Cam - A different perspective

This weekend we trialled our Pan Cam to try to get a different perspective on a water rocket launch. The camera is set up on a tripod and controlled by an RC servo, so that when the rocket launches the camera pans with the rocket to keep it in frame.

We were happy with how the videos turned out. The full details and video have been posted on our main website here:

http://www.AirCommandRockets.com/day108.htm

Update: The original concept of the panning camera for a water rocket triggered by launch was first developed by wyldbytes. He presents his idea here: http://www.wyldbytes.co.uk/?p=225 as a part of an automated and servo controlled launch trigger. A video demonstrating the concept is here: http://youtu.be/F284FmfZuMI

This is the Pan Cam camera:

Here is a captured video frame from the camera:

Quick update

I've done a quick update on the main site from the last test flight launch day:

http://www.aircommandrockets.com/day107.htm

The last couple of weeks have been really busy with the timers so not a whole lot of new rocket development has been happening. We want to thank everyone for their support on the timers. We ran out of stock from the initial run a lot sooner than we thought, but new parts were ordered over the weekend so hopefully they should start arriving shortly, and the timers will be available again soon after that. Some of the components come from the US and some from the UK.

Servo Timer II now available

Well it has taken a lot of procrastination but the timers are finally finished. :) You can use the timers for parachute deployment, staging, pointing a camera etc. The full details and user manual are available here:

http://www.AirCommandRockets.com/servo_timer_V2_0.htm

They are now available for purchase including FREE world wide delivery. All you need is an RC servo motor and a battery, and a rocket or two of course. These timers weigh around 6 grams and are small enough to fit inside of T8 FTC rockets.

We've done around 20 flights with these now and are quite happy with the results.

Test flights

We had a great day yesterday for launching rockets. The skies were blue and there was virtually no wind. We wanted to do some further testing on the servo timers to make sure they work well in real life after the latest round of firmware changes. I was particularly interested in the slow takeoffs and how well the false trigger filter worked with the G-switches. We managed to get 5 flights in on the day and the timers worked well on all the flights.

I'll put together a short update on our main site in the next couple of days.

Servo Timer II update

Progress has been continuing on the Servo Timer II. I've received all the parts now and have started production of the timers. I've been doing some final tweaks on the firmware to try to cover the greatest range of servo timings, as well as adjusting the G-switch false trigger filter.

I'm going to do some final flight testing if the weather is good this weekend, and then finish the documentation. I'm mounting these inside a few new nosecones and will fit them to a number of rockets. These things have definitely taken a lot longer than I would have liked. Hopefully not long now before they are available.

N2000 Drag Race

I've put together a highlights video of the N2000W drag race from the Williams "Wildfire" Westernationals this year in Perth. The theme for the whole launch weekend was the "70's" with quite a few of the guys growing mo's in the lead up to the event. :)

http://www.youtube.com/watch?v=9spkgBYapos
 
The drag race was between the guys from QRS and CGN. It was definitely a fun event to watch.

More great photos like this of the event are here:
http://ausrocketry.com/forum/viewtopic.php?f=37&t=3045&start=15

How much water?

One of the more common questions that's often asked is how much water should I put in my water rocket? The standard answer usually is 1/3 of the rocket capacity, but because the ideal amount of water is dependent on a number of factors this amount is rarely exactly 1/3 .

This week we look at how some of these different factors affect the optimum water amount:

http://www.AirCommandRockets.com/water.htm

The article compares how the optimum changes with pressure, nozzle size, weight and liquid density.

Williams "Wildfire" Westernationals 2011

We just returned from an awesome weekend in Perth attending the Williams Wildfire Westernationals. This year the whole family came along so it was good for the boys to experience Australia's biggest launch event of the year. There were so many great flights, and quite a few highlights, from the "Mach Madness" entries to the N2000W drag race. A big thank you goes to Dave and Mel for organizing this fantastic event.

Here is a photo of Samantha's L3 rocket "Lucky Seven".
(A standard sized kid used for scale reference)

I will be posting photos and videos in the coming days as there is a lot of footage to go through. Can't wait to get back to the workshop and start building again. :)

Measuring Bottle Stretch Thrust

Last weekend we did a little experiment to measure the thrust produced as a bottle contracts while depressurising. From earlier experiments we learned that bottles can stretch significantly and we wanted to know how much of this energy is returned during the boost phase. The main idea behind this experiment was to help refine future models of water rocket thrust behaviour. The full experiment writeup is here:

http://www.AirCommandRockets.com/day106.htm

We also compared the thrust produced by stretching alone to the thrust a regular rocket produces.

10 Water Rocket Challenges

Over the last few weeks we’ve been putting together a series of challenges that people can attempt with their water rockets. These challenges are designed much the same way one would collect scout badges when they have achieved certain activities. Each challenge is also designed to address a different aspect of the sport.

For each challenge you achieve you are awarded a patch that you can place on your website, blog or video. There are no judges or approval processes, and patches are purely self-awarded on an honor system when you believe you have achieved the challenge in the spirit it was intended.

You should also be able to attempt all the challenges at your local park, but be warned these challenges are difficult!

Are you up for a challenge? …. Read More....

Polaron G2 flight day report

I've uploaded the update from this weekend's NSWRA launch on our main website here:

http://www.AirCommandRockets.com/day105.htm

The update includes photos and video of the Polaron G2 launch. The flight was encouraging for us in order to keep pushing further with the G2 development. Although the 210psi launch pressure was 20% lower than what the rocket was designed for, we decided to at least get a couple of good flights in before increasing the pressure again. Also encouraging is that the simulator results from two different simulators predicted the altitude quite accurately for this flight. This means we can continue to use the simulators to predict the behaviour of this class of rocket.

The G2 in this configuration still has room for improvement on two fronts. Each 10psi increase in pressure beyond the 210psi adds around 50 feet to the altitude. These pressure chambers have been hydro tested to 270psi. The rocket is designed to be extended by a further spliced-quad like we used in the first attempt. This extra spliced quad should add a further 100 feet or so. How the rocket stands up to higher speeds and stresses is unknown at this stage, so more fights will follow.

We also flew a second high pressure rocket on the day - Axion G2 - that is based on the Axion series of rockets. The rocket flew well, but failed to deploy the parachute and crashed. I can see the G2 name is going to get confusing here. The 'G' in the name simply stands for "Glass"-reinforced and the 2 is just the second in the series.

Polaron G2 - flight

Perfect launch conditions today for the G2 launch. Virtually no wind and mostly blue skies. The G2 had a great flight and the higher power was quite evident from the sound it made. We're putting together the launch day report along with the highlights video, which should be on our website in the next few days.

Servo Timer II - boards

We received the PCBs for the Servo Timer II from the manufacturer yesterday. We decided to use PCBCart this time around as they were well recommended and our experience with them so far has also been very positive.

I soldered up a couple of the timers yesterday to check that I didn't stuff up on the board, but luckily the circuit powered up first go. We are going to continue more flight testing with these in the coming weeks. I'm just in the process of ordering the components for them in bulk quantities, but it will still be some time before they will be available. 

Quick Launcher and on-board HD video

We tested the new launcher this weekend with a couple of small rockets at the local park. It is very easy to setup and pack up again. Transportation is a lot easier as well. I've posted an update on our main site with details on how it works, as well as a video showing how it's set up and used.

The update is available here: http://www.aircommandrockets.com/day104.htm

The Quick Launcher in it's packed up configuration.

We also test flew our first HD camera on a rocket. For the $40 we paid for it, it produces pretty nice quality video and it's lightweight. The above update includes a couple of videos from the camera, though it's lower quality because YouTube re-compresses it.

 Panorama constructed from 3 images from the HD camera.

Repairs

This week we've been repairing the damage to the G2 rocket. Last night I finished the G2 backup parachute system. The fairing is new as is the coreflute framework. I straightened all the bent pins on the electronics and resoldered all the severed wires and fitted new connectors. I also replaced the 3 Lipo batteries. All the electronics are the same from the original rocket including the servo motor. Despite being scattered in a wide area in the explosion, it's surprising that all the important bits survived. That's around $200 worth of electronics. I'm still waiting for the camera and micro SD cards to be delivered hopefully this week.

Repaired Backup parachute system with altimeter.  

 The main deployment mechanism is also pretty much repaired and only needing a new coat of paint. There was only minor fiberglass damage to the body.

Damaging the medium launcher in the explosion is giving us the opportunity to redesign the launcher. The new launcher is going to be a single rail design and the rocket will use buttons to attach to the rail. The main driving principle for this launcher is quick setup and portability. The medium launcher although very versatile was taking around 10 minutes to set up and 10 minutes to take down. The new launcher should be about 2 minutes.

Polaron G2 CATO

We had an interesting weekend this week. We finished the new Polaron G2 rocket, and took it out for a launch. Unfortunately things did not quite go according to the script.

The full flight day report gives details how we created a nice sculpture for the rocket range.

http://www.aircommandrockets.com/day103.htm

The report includes a highlights video including the CATO in slow-mo.The rocket and launcher are already being rebuilt and we will have another go again soon. The website update also has more detailed photos of the new side deploy mechanism and payload bay with a backup parachute.

Servo Timer II test flights

This weekend we went down to the local park to start the Servo Timer II trial flights. We flew a total of 7 flights with the timer and thankfully all worked well. Two of the flights included the uMAD for triggering the timer at apogee.

The full launch report along with a highlights video is here:


http://www.aircommandrockets.com/day102.htm

We are now preparing larger rockets to continue the tests. We would like to do an additional 10-15 more flights before starting a production run of the timers. Yesterday I was going to do some tests with one of the timers, and noticed that I had left the power switch ON, and completely drained the battery over the last few days. So this morning I updated the firmware to flash the LED briefly every 5 seconds to remind me to turn the power off.

Website Issues

We host our website with GoDaddy, but it looks like they have been having some issues over the last couple of days. It was up briefly yesterday, but it looks like they are having issues again today. Lots of people are reporting the same problems as well. Hopefully the website will be up again soon.

Wet but productive weekend

Unfortunately we didn't get to test fly the servo timers this weekend as it pretty much rained both days. We had over 100mm at our place. So it was a good time to spend in the workshop. We are trying to build up our inventory of spare parts so we can focus on flying rather than fixing. I'm also trying to get components ready for rockets to fly at Williams later this year.

We are making a big run of spliced quads at the moment that will be fiberglassed, both 90mm and 110mm. This weekend we cleaned, cut, shrank and curled some 70 bottles.

Here they have been shrunk and are ready to be curled.

After curling they have been paired up ready for sanding and gluing. This should give us about 10 x 110mm quads and about 11 x 90mm quads.

We also fiberglassed two more 110mm spliced quads yesterday. These will be used as spares on the flight day of G2. We have 6 of these now, with 4 of them still needing to be pressure tested to 270psi. Some of the fiberglassed 90mm spliced quads are going to be used in Acceleron V's sustainer. I'm looking forward to this flight as it will be our first dual pressure launch.

We also made a new 90mm nosecone with the Servo Timer II which uses the small LiPo batteries. This new nosecone including the fairing it sits on weighs in at 86 grams. Our regular nosecones weigh around 154 grams. The nosecone also uses a new ejection plate mechanism that has more force to get the parachute out. I'll post details and photos with the next web page update. We are using the same technique for ejecting the G2's backup parachute.

We are currently planning to launch the G2 with just 3 spliced quads (~15L) on the first flight, just in case the rocket again decides to drill a fence post hole. If the first flight goes OK, then we will screw in the fourth bottle and launch again.

ServoTimer II video

I've posted a video on YouTube of the Servo Timer II prototype in operation. The video shows the normal operation, configuration, as well as how to interface it to external sensors like the magnetic apogee detector (MAD) from Whooshtronics. It also shows how you can chain the timers together for driving multiple servo motors for things like staging and parachute deployment, or drogue/main parachute functionality.


http://www.youtube.com/watch?v=xYx-oPSQK8c

Panorama tutorial

I've uploaded a tutorial on how to make panoramic images from on-board rocket videos taken with small cameras such as the 808 keychain or MD80 clone.

http://www.aircommandrockets.com/panorama.htm

It requires you to have Photoshop, and VirtualDub (which is free).

ServoTimer II prototype

In the last couple of days I've soldered up the first prototype of the ServoTimer II.

 Top and bottom view of the timer

 Here it is next to V1.6 of the flight computer

I finally, got it running and bench tested tonight. I'll make up a couple more in the upcoming days and then fit them in deployment mechanisms and test fly them quite a few times. If all goes well, then I'll get actual boards made by a PCB manufacturer.

All up it weighs ~6 grams with the battery clip adding another 2 grams.

Foam flights

This weekend we went to the NSWRA launch event again, but because we didn't have the Polaron G2 rocket quite ready yet, we just flew smaller rockets. These were basically assembled the night before launch out of spare components. The update is here along with a highlights video:

http://www.AirCommandRockets.com/day101.htm

Bottle Splicing Tutorial

Over the last couple of years we’ve had a number of requests for a tutorial on splicing same sized bottles. We found that the technique we used to use ( http://www.aircommandrockets.com/construction_2.htm#SplicingBottles ) would work on 1.25L bottles but did not translate well to 2 Liter bottles. No matter how carefully we would do the symmetrical splices on the larger bottles we would often end up with a small leak and the whole splice had to be thrown away. Sleeves larger than 2L bottles which could be shrunk to size were also increasingly difficult to get.

So we developed a modified splicing technique, that we now use for 2L bottles. We posted the technique in outline form here http://ausrocketry.com/forum/viewtopic.php?p=26084#p26084 last year, but finally got around to actually finishing the tutorial this week. Talk about dragging our heels.

It’s by no means the only way to splice 2L bottles, but it’s a technique we’ve found reliable and haven’t had a single leak since we started using it. The splices hold up well to repeated launches and non-destructive pressure test cycles to 140psi. We are currently using it on our Acceleron V and Polaron VII rockets.

Here is the full tutorial that also includes a how-to video:

http://www.aircommandrockets.com/construction_6.htm

If people do end up using this technique, we would love to get feedback about what worked for you and what didn’t and perhaps ways to improve or even simplify it.

Polaron G2 - Flight report

I’ve finished uploading the flight report from last weekend. The report has information about what we think went wrong and includes photos and a highlights video from the day.

http://www.AirCommandRockets.com/day100.htm

 

We are in the process of rebuilding the rocket, so hopefully it won’t be too long before it’s up in the air again. It’s always easier to build the rocket a second time, because we know how to build it and what materials we need. The first build always takes a while as we try different prototypes.

Polaron G2 - First flight

We launched the G2 rocket for the first time today, but the flight didn't quite go according to plan. As a result the rocket could now almost fit in your car's glove compartment. There were a couple of small issues that will need fixing, but overall not too bad. On the way home from the launch site we figured out what we need to do, and will start on the repairs today. We are hoping to have it ready again for the next NSWRA launch.

I will post the usual flight day report in the coming days. Though the rocket was ....well let's not beat about the bush.... destroyed, we did learn a lot from the attempt, and though disappointing, as always this is just another step in the development process.We have altimeter & acceleration data as well as on-board video so that will gives us more information about what to expect on the next flight.

... right time to head back to the workshop.....

G2 nosecone test flights

This weekend we went down to the local park to test fly the G2 nosecone on a small rocket. Both flights went well and so we can now mount the nosecone on the G2 rocket.
I've put together an update on our main website with more pictures and a video that shows how the mechanism works as well as footage from the test flights.

The update is available here:
http://www.AirCommandRockets.com/day99.htm

3 Projects

Although I haven’t done new updates to the main website for a while, I have been busy with 3 rocket related projects, mostly the reason I haven’t done an update. The main project has been to get the Polaron G2 flight ready. As a part of that I have the deployment mechanism ready for flight testing on a small rocket this Sunday at the local park. If everything goes well, I’ll mount the mechanism on the G2 rocket ready for next week’s launch. Craig lent me one of his latest flight computers to fly along and gather data. It will also serve as a backup altimeter for the flight. I still need to mount it in the payload bay.

The second project has been writing an application to go with Craig’s flight computer that can visualize the recorded data and configure the flight computer. I’ll post more data on this later with the first official release of this application. This has been taking up at least half of my rocket time.

The third project is the next iteration of the flight computer we use in our rockets. I’ve got the prototype working now on a breadboard, and all the new firmware has been written. I’m currently choosing the final SMD components and then I’ll finish off the PCB layout. This version is simpler to use and less than half the size and weight of V1.6. It should also be cheaper. It will still be a while before these are available as I need to write the documentation and do flight testing first. At the moment it’s looking like 3 months or so due to all the other projects.

Christmas vacation

It’s been a while since the last update. We’ve just returned from 3 weeks in Colorado enjoying the solid rocket fuel … err I mean snow with the family over Christmas and New Year, but it’s good to be back in the warm weather again.

We have a much better appreciation for what it would be like launching water rockets in the cold weather. While there we visited one store in a small town called the “Nearly everything store” http://nearlyeverythingstore.com/. The store itself is quite small but they do have a huge selection of stuff. Amongst the toys, guns, pharmaceuticals, fishing gear, office supplies, crafts and snow gear they had a good selection of pyro rocket kits as well as motors at a great price, and what impressed me the most was that I even found tornado couplings there! So I bought a couple. :)

We got to visit the air and space museum in Denver as well. Here I am explaining the finer details of how a cruise missile attaches to the B1 just above our heads, while leaning on the thermo nuclear device just behind us. This museum is definitely well worth a visit. 

I also purchased a number tubes of PL premium while in the US. From the last trip I knew to leave them near the top of the checked-in luggage for easy inspection by the airport TSA authorities. Sure enough, out of the four bags we had, the two that were inspected were the ones with the glue in them. I knew they were inspected because the TSA officials left a slips of paper inside the inspected bags. But all is good, and so we have more glue now for splicing. We didn’t have any issues going through customs in Oz. We still had a couple of tubes from the last trip but they are approaching their expiry date.

With the trip over we can now again start concentrating on building and launching more rockets, and more frequent updates as well.