Fins and Fiberglassing

As a part of the work we are doing with Polaron G2, we are looking at different fin materials.

This week we are comparing 3 different ones. The first one is a regular 4mm 3-ply plywood fin. This fin is very tough, but the main drawback is its weight. At 74 grams it is the heaviest. Thickness is 4.2mm.

The second one we tried making out of two 1.5mm sheets of balsa wood glued together at 90 degrees to each other with PVA glue. We then put one layer of 200gsm fiberglass on either side. Epoxy resin was used for this. The fin is quite tough and weighed in at 43 grams. The thickness is 3.9mm but the main drawback is the amount of work involved to do this and the higher cost.

 The 3 fins tested. Left to right: corriflute, balsa/glass sandwich, plywood.

The last fin is made from corriflute, the material we have been using until now. It weighed in at 25 grams, but has a thickness of 5mm. It is quite tough, and has a good finish, but the main drawback is that it is made from polypropylene and hence harder to glue and paint. The leading and trailing edges are also harder to create nice and smooth.

So far the balsa sandwich is probably a good compromise, unless we can find some nice lightweight plywood.

We have also spent some time this week getting Acceleron V rebuilt and serviced so it can be launched again. We also did a 50psi leak check. We'll try to launch it again soon just for fun.

We were supposed to go out to the NSWRA launch today, but after driving half way there in pouring rain, we decided to turn back. As we got back, the weather cleared up but the wind had picked up. So we went back to the workshop and fiberglassed 3 of the spliced-quads. We are going to give them at least 5 days to fully cure before pressure testing. We are going to try to push them to 270psi for the 250psi launch pressure. We'll see how much they'll actually hold.

 3 x 5.3L spliced quads wrapped in fiberglass.

Polaron G2 - Development continues

I've updated our main site with some of the progress that has been made on getting G2 assembled. It's good to be able to see it in actual size rather than just on paper. It made me realize that we are going to need to rethink some of our logistics in terms of getting the rocket setup on the pad and configured. We are going to need to bring a full size ladder. The update is here:

http://www.AirCommandRockets.com/day96.htm

I had to take photos of the rocket lying down, as the ceilings are too low in the house to stand it up. We are going to need an extra long guide rail for this rocket too. Most likely 2.5 - 3m long.

The update also includes a highlights video from the last weekend's NSWRA launch where we tested the Mk3 stager with a more powerful booster. The flights went really well, and the stager performed as expected.

Here is a size comparison diagram for the Polaron G2 rocket. 

 Here it is starting to take shape lying next to Polaron G1.

Joe Genius - Rocket Science

A bit of fun this week. One of our video clips made it onto this week's episode of Joe Genius:

http://revision3.com/joegenius/rocketscience

The clip (shown about half way through the episode) is around 3 years old now - here is the original that it came from:  http://www.aircommandrockets.com/day24.htm

What else would you do on a hot day? :)

Splicing production line

We have spent the last few days cleaning, cutting, shrinking, curling, sanding and splicing quite a few 2 liter bottles. These will form the pressure chamber for the Polaron G2 rocket as well as the boosters. We are making a number of “spliced-quads” that are just a couple of spliced-pairs of bottles, spliced together. This gives us a longer section of rocket body that is more efficient since we get more volume per length of rocket while still retaining the modular aspect of the design.

When all the splicing is finished, we will reinforce all of the bottles with fiberglass.  Each spliced quad has a 5.3 L capacity. Phase 1 of the G2 will combine 3 of the spliced quads giving a total capacity of 15.9 L. Our current thinking for phase 2 is that we are likely to add a spliced pair to the bottom as the foam mixing chamber. This will increase the capacity of the main stage to 19 L.

Some 2L spliced-pairs, 1.25L spliced-pairs as well as a spliced-quad.

We are making a few spare spliced quads with the idea that some of them will likely fail pressure tests, others will be used for burst tests and some will get damaged on landing. We want to have at least two complete G2 rockets ready for a launch day in case something goes wrong or the other can be used for spare parts. 
 

Polaron G2

Okay time to get a little more serious with these water rockets. We haven't really been optimizing a lot of our rockets as we carried out various experiments. But it's time to start pushing the envelope a little more with the next set of rockets. These will focus on optimizing the rocket as a whole for better performance using the lessons we have learned.

Polaron G2 is a new rocket now in the planning stages, and we are starting to gather materials for it.

Here are a few 2L bottles ready for processing into rocket components. We will also be trying out some new construction techniques. Polaron G2 will follow the Polaron series of rockets in overall design, and will be developed in 3 phases. The first phase will be a full size single stage rocket, with drop away boosters in phase two, and with phase 3 a small sustainer will be added to the main stage.

Time allowing I will try to keep this blog updated with more regular progress, with major milestones covered on our main website. We are revisiting each aspect of the rocket and seeing how things can be improved. The rocket will also need an upgraded launcher with a longer guide rail.

Currently the target launch pressure is at 250psi, but things may change depending on how various tests go with the design.

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MAD Deployment

I've updated our main website with the road trip report to Parraweena. We test flew PK's Magnetic Apogee Detector on a couple of the flights and it worked very well. We also did a couple of 2-stage flights testing a sustainer support brace for the Mk 3. stager.

The update is here: http://www.AirCommandRockets.com/day95.htm and includes photos, as well as a highlights video.

PK's Magnetic Apogee Detector.

2 Stage rocket testing the Mk 3 stager sustainer support brace.

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Road trip to Parraweena

We had a great weekend this week attending the launch at Parraweena. The weather couldn't be more perfect with sunny conditions and almost no wind. There were a couple of minor dramas getting there, but definitely well worthwhile. We saw some great rockets go up and had a chance to test fly some of our rockets as well. I am in the process of writing up a trip report and will post it with pictures and video in the next few days.

Here is a photo of a larger 2-stage rocket testing the Mk3. Stager.

Photo: Darren from Suburban Rocketry.

I also flew my larger pyro rocket on a G64 which was a very nice flight. I mounted a camera inside to get a view of the area from the predicted 3000 or so feet. The flight was very good and managed to get reasonable video from it.
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Mk3. Staging Mechanism Details

We’ve uploaded the full details of how the Mk3. staging mechanism works to here:

http://www.aircommandrockets.com/howitworks_4.htm
 
And a full tutorial on how to build it is here:

http://www.aircommandrockets.com/mark_3_stager.htm
 
The tutorial has step-by-step instructions with photos as well as a 2 part video that shows the procedure.

We’ve also uploaded a launch report of all the test flights we have had with the stager over the last 2.5 months. The launch report contains a highlights video from these launches:

http://www.aircommandrockets.com/day94.htm

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More Mk3. Stager test flights

This morning we had good weather and so we took the Mk3 stager test rockets to the local park. It was a little bit breezy but we decided to launch anyway. The stager had 3 out of 3 successful flights again which was good. We did get one of the sustainers stuck in a tree, and had to come back later in the day to retrieve it.

I am currently putting together 3 videos about the stager. One is a highlights video of the test flights from the last two months, and the other two are a 2-part tutorial on how to build it. We're also writing up a construction tutorial for the website with photos. It's a lot of writing/editing to do, so I expect it will take at least a week to get it all put together. We also need to use some spare time to prepare more rockets for next week's Doonside launch.

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Slow progress and weather

It's been a while since the last update. In the last month we've had family visiting from overseas and spent about a week up in Cairns snorkeling at the barrier reef with the kids. It was nice to have a break from cold Sydney. We have also temporarily swapped houses with my parents so that the visiting family could all stay in the same house with us. Our house just couldn't handle 7 people comfortably for a month. As a result I haven't had easy access to my workshop.

But excuses aside, some rocket development has been continuing. In the last couple of weeks we built a couple of bigger test rockets to test the Mk3. Stager. We were supposed to do the final trial flights today, however, the Doonside launch has been canceled due to rain and muddy conditions making the launch site inaccessible.

We are hoping that the weather will improve tomorrow morning, so we could try the rockets at the local park at a lower pressure.

Here are the two rockets fitted with the Mk3. stagers ready for test flights. We built two just in case there is a problem with one or if it crashes and gets damaged.

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Mk3. Staging Mechanism test flights

This morning dad and I went down to the local park to continue with the staging mechanism test flights. This was the third separate set of test flights, with minor failures on the first two sets. We finally got the stager working properly today on 5 out of 5 launches so we were happy. We only flew the stager on a small booster (2.1L spliced pair) and a 1.25L second stage. The flights were done at 110psi and 120psi.

Next we'll need to test it on a larger rocket a few times, but will need to take it to Doonside for testing as the local park would be too small for it.

Here you can see the small sustainer shortly after staging. The parachute is already being deployed on the booster.

If the next set of tests proves successful, then we'll post a full tutorial on how to make it.
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Doonside Launch - certification

It was a good flight weekend this week. As we are mid way through preparing the next water rocket for flight, and the launch weather looked iffy for Doonside, I decided to only bring the new pyro rocket "Waterless" (a LOC/Precision Weasel) with me as well as Paul's "Pod 2" rocket.

I had been wanting to fly the new rocket for a couple of months but didn't have a motor for it. I finally flew it on an E15-4W and it was a good flight. The delay seemed on the long side and the parachute opened a little late, but it was a good recovery and the rocket landed without damage. The flight was my mid-power certification flight so I was happy. I can buy up to G motors now. :)

We have had a couple of small water rocket launches at our local park since the last main website update as we are testing a staging mechanism, but have had a couple of failures, so after a couple of modifications we are ready to try it again. If the design proves successful, I'll post full construction details.
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Williams Westernationals 2010 Highights video

I've finally finished editing the video of the trip to Perth from a couple of weeks ago. I've also used a number of clips shot by Shane Miles as he had some great detailed shots of the high power launches.

Here are the highlights from the two HPR launch days:



(It's best to view the video at 480p or HD in YouTube)

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Parachute Cam and Polaron G1

This weekend we a had a really good launch day. The weather was perfect and the rockets behaved themselves. During some unrelated test flights we took the opportunity to mount one of the tiny MD-80 cameras in the center of the parachute looking down.

Although quite a bit shaky, the video did give us a different perspective on the rocket in flight. The full launch report including photos and a highlights video is available here:

http://www.aircommandrockets.com/day93.htm

The update also includes the test flights of the fiberglass Polaron G1 rocket. On the second flight we flew it at 230psi to 751' (229m) which was our highest (by 5 meters) single stage flight.

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Williams "Wildfire" Westernationals 2010

This weekend I took a break from water rocket development and headed over to Perth to attend the Williams "Wildfire" Westernationals 2010.

What an awesome experience it was to see a lot of high power rockets go up. It was great to finally meet a lot of the people in person from the Australian Rocketry forum as well. They are great bunch of guys too. A big thank you goes to Scoop and Mel and all those who helped organise and cater the event.

Congratulations to all those who did their L1, L2 and L3 certifications.

Here are some pictures from the event:

http://ausrocketry.com/forum/viewtopic.php?f=37&t=2189


Very strong the dark side is ......

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Water Rocket Labs

Well finally after many delays and procrastinations, I've uploaded the website extension. Originally it was going to be a separate entity, but I have decided to just make it a sub-section of the new site. This also makes it logistically easier to administer.

"Water Rocket Labs" was developed to help water rocketeers make better decisions about building their rockets. The site provides data and analysis about various aspects of water rocketry including materials and their performance.

The focus is not only on the data itself but also on the procedures and test equipment used to obtain the data. This allows others to follow the same procedures and compare their results against the data presented at the labs. The data is cross linked to the experiments, test procedures and test equipment used to obtain them.

Some of the experiments included in the site have been published before on our main site, however, there is a range of experiments we had not published before. With the previously published results I have trimmed them down only to the relevant information.

We will continue to update our regular site with launch reports, articles, construction details etc, but all new science or engineering results will go into the Labs section.

There are around 80 pages of information in the extension. Some sections are still sparsely populated, but we now have the framework to add more data as we obtain it.

Here it is: http://www.aircommandrockets.com/labs/index.htm

We invite people to submit their data to the Labs that will hopefully help others make better decisions about building water rockets.

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Water Rocket Launcher Article

Over the last month I've slowly been putting together an article to help explain the range of different launcher design options rocketeers have when building their own.

The article is available here:

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

Along similar lines as the recovery guide I've tried to include lots of links to examples showing how the different components have been implemented by the water rocket community.
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Moving Main Website

I've been putting it off for long enough, so this weekend I have started relocating our main website. Up until now we have been hosting it on a free 50Mb partition we get with our ISP. The problem was that we were running out of room, well for quite a while now actually, so a lot of the actual images had to be hosted elsewhere.

To expand the 50Mb partition just wasn't possible with this ISP without signing up for actual 'hosting' where they wanted another $50 setup fee and then an extra $110/year for 100Mb of space. That was just ridiculous. So we have gone with an alternative hosting company where we only pay $70/year for 10Gb of space.

The usual domain: http://home.people.net.au/~aircommand/ will be replaced with http://www.AirCommandRockets.com/ . We've had the AirCommandRockets.com domain registered for quite a while but it was getting forwarded to the people telecom site.

I will be replacing the people telecom pages soon with forwarding pages to the new site, and eventually remove them completely. If you have links with http://home.people.net.au/~aircommand they can simply be replaced with http://www.AirCommandRockets.com as all the underlying website structure remains the same.

The AirCommandRockets.com site is now live but there may be a number of disruptions over the next week or so.

The extra space will allow us to upload the website extension we have been working on and have had to put on hold until we had more space. We'll also now be able to add extra features to the site, that weren't possible before.



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Testing beyond 300psi and old videos

This week dad set up new test equipment for us to use so that we can test beyond 300psi. Which is what our high pressure test panel went up to. We now have test capability up to around 800psi, though we would need to replace the air hose with a high pressure one for the upper range. We mostly wanted to see at what pressure the fiberglass bottles will fail so that we know what the safe launch pressure is.

We now have a nice giant pressure gauge which makes it easy to see.... even by those at the back of the classroom. :)

As we look to upgrade Acceleron V to higher pressures we have to check the individual components to see if they will be up to the job. Here dad was testing the thin plastic tubing we are using for the sustainer air supply line. It goes between the baseplate release mechanism and the staging mechanism with a non-return valve along the way. It says on the side it is rated to 50psi operational pressure. We have been pressurising it to 130psi (having previously tested it to 180psi) With our rocket pressures now nearing 250psi, this was always likely to be a weak point ......

Here it is still holding around 630psi! ....If you notice in the background, the whole experiment is now covered with a pile of concrete pavers.

Old Videos

About a week ago we noticed that some of the older videos on our website weren't playing. I'm not sure how long it's been like that. These mostly covered flight days 1 to 55. It turns out MySpace changed how videos are embedded and that broke all the existing embeded URLs. *sheesh*

So tonight I've gone back and fixed up all the embedding code to reflect how MySpace wants to do it .... until next time. We've stopped using MySpace around day 55 for our videos and now almost exclusively upload to YouTube.

I must go back and check over other broken links on the website as some things have disappeared. I try to fix them as I come across them, but there are always new ones. If people come across broken links please let me know and I'll try to fix them if possible.
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Fiberglass rocket launch report

I've updated our main website with the latest launch report on the flights of one of the fiberglass rockets. The update is available here:

http://www.AirCommandRockets.com/day92.htm

It includes photos and a highlights video from the day. The small rocket that was launched at 245psi managed to get up to 744' (226m). We thought that was pretty reasonable considering it was slightly bent, used a small 9mm nozzle, and no launch tube. .... right... can't sit around here typing .... must get back to the workshop :) ....

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