Since our last carbon update things have been coming along extremely well with many hours dedicated to our composites work, plying our trade and improving all the time. To date we have produced 3 lower spats (fairings) and two upper spats and have another upper spat ready to be cooked tomorrow morning. The last few in particular have been turning out rather nicely as we become more accustomed to working with the wonderful stuff that is carbon fibre. The best bit is unwrapping it, while the moulds are still warm, and pulling out a nice shiny new part!
Over the next week we are planning to move on to laying up the canopy windshield, rear view camera and number plate offsets using wet layup resin. Once these offsets have been created we can move on to cooking some bigger parts in the big oven as a trial for the top shell. There will be lots to learn when we fire it up for the first time. Lessons from the small ovens include, how to avoid melting lots of breather, how to avoid noxious fumes when trying to use high temperature foam core to stop melting the breather and how to cure parts in under 12 hours! Highlights from these learning experiences include staying in the workshop till the early hours of the morning while curing the first lower spat.
We have been enjoying the camaraderie of spending time in the workshop with the tunes blaring listening to Smoky Joe sputter away like clockwork. I’d like to claim, on behalf of the carbon team, we have had the most fun out of any team in Sunswift and it all started on our first night out to some fine Lebanese dining. May the good times continue!
This next month we will be posting some personal reports from team members who will share the projects they are working on in the lead up to this Octobers World Solar Challenge. Today’s story is once again from the electrical team from one of our newer members, Rob.
Over the past few months I have been working on updating our GPS barometer module. While we still have one of the last version working, Sunswift would like to make sure there is backup for every piece of electrical equipment in the car. This means if something breaks, it will be a simple swap job, and the car can get back on the road quickly.
Building on the previous design, I have included a better GPS unit and a new barometer board which outputs atmospheric pressure and temperature. These will be used in monitoring the car and its position to assist in the strategy for the race. This module is an integral part of our telemetry network. Soon we will have a new way for members of the public to keep up to date with where we are, while on the race and in the lead up to the race, but we’ll have more news on that soon.
GPS Barometer PCB Board
As a newer member of Sunswift, this has been an interesting and challenging first project. The PCB is finished, (see the picture above) and the next stages are to print and construct the boards and then program the microcontroller. The microcontroller has been updated to include the CAN communications with the rest of the car. The GPS is being secured to the board more firmly to increase the durability of the module.
Rob Makepeace -Electrical Team
Hey guys,
We’ve made a few posts recently but getting them onto facebook and twitter slipped through the cracks. We’ve just got a new magical plugin for our blog that will tweet/share automatically when we post an article.
We’ve got a few other things in the pipeline aimed at letting our fans know what we’re doing. Stay tuned, plenty more updates to come!
Dan
Early in 2011 we started work on a new wheel motor. The current wheel motor (designed by Lyndon Young) has been in use since 1998 with no significant changes.
We thought that after 12 years of computer advancement and development in solar car wheel motor housings we could do something a bit better.
We wanted a motor that would be competitive with the current top teams in terms of weight but that wouldn’t break the bank.
We originally looked at sand casting as a method of production, and the motor has been designed with that in mind. It consists of a minimum number of very simple parts, for cheap and easy manufacture.
Despite the initial excitement over a cast wheel motor, even with sand casting the costs are comparable to CNC machining for the low run we wanted. Because of this, we are going to have the prototype CNC’d for the upcoming race.
A shiny CAD model of the new wheel motor fully assembled
The design is a two-part wheel following the ‘widow maker’ school of design. The rim is incorporated into the wheel halves and keeping the air in the tyre without allowing the wheel to be blown apart has been quite a challenge to design for.
A shiny CAD model of the new wheel motor with one half removed.
We are currently conducting detailed FEA on the design and hope to have it sent off for machining within the next fortnight.
'Brochure filler'
In June one of Sunswift’s founding members, Michael Wheatley, died of unknown causes. Michael joined the team in 1995 as the fifth member and raced with Sunswift I in the 1996 World Solar Challenge. He went on to become the electrical team leader in the Sunswift II project, culminating in our 1999 Transcontinental attempt from Perth to Sydney.
Michael (3rd from left) during filming of the weather report with Tim Bailey with members of the Sunswift I team (1999)
Michael (8th from the left) with the first WSC team in 1996
Michael (right) with wife Emily (centre) at the end of the Transcontinental World Attempt in 1999
Michael then retired in order to pursue a PhD in Chemical Engineering, working on the systems issues associated with dye-sensitised solar cells. Since then he has kept in touch over various races. He built a spur-of-the-moment battery discharging system before the 2005 WSC that we still use, dropped by the workshop before the second transcontinental record attempt in 2007, and in 2009 provided encouragement and advice to the management team in the lead up to WSC09. He and his wife Emily participated as official race observers in recent races.
Michael was a die-hard solar and solar racing enthusiast, who loved both the engineering challenge and the opportunity to improve the state-of-the-art in renewable technology. We’ll certainly miss him.
Over the past year numerous students have undertaken thesis work as part of their degree to improve components within the solar car. Irving in the electrical team has been working at NICTA on the Sunswift IV Observer Node (SION) that will replace the old PLEB (Pocket Linux Embedded Box) in the telemetry system. The PLEB was used in the solar car to convert the data carried by the CAN protocol into the Ethernet protocol. The main goal of the thesis was to provide a better system to achieve this.
The SION performs various tasks that can be broken down into sub-systems in order to deliver data including:
- A CAN interface to access the CAN bus (CAN controller);
- A wireless interface to send data remotely (Wireless from solar car to control vehicle);
- A processing unit to manage the flow of data between the two interfaces. This can be in the form of a microcontroller or an embedded computer (CPU);
- A persistent memory to store data in case of telemetry breakup (Storage);
- A power supply circuit to power the other subsystems (Power Supply).
The system block diagram, showing the subsystems and the hardware fulfilling their roles.
The major improvement from the PLEB is the SION’s ability to handle broken wireless links. Previously, much of the telemetry data generated during this condition would be lost due to unreliability. Now when the connection is broken, the SION logs all telemetry data internally in a more reliable manner, thus a copy of the data will still exist on the solar car. The data can then be retrieved through the wireless connection when the control car comes back within wireless transmission range, or alternatively at the end of the day when physical access to the solar car becomes possible. In addition it also uses less power then the WAP used alongside the PLEB.
Completed board after design, population with components and debugging ready for use.
Excerpts from Irving’s thesis compiled by Clara Mazzone.
This week carbon building phase officially commenced.
As the team decided to purchase a new solar array for this year’s race we thought it prudent to also build a new top shell enabling two functioning arrays/top-shells, one for the race, one for training and public displays. Some minor adjustments have been made to the new top shell design for aerodynamic purposes.
Since the closing of our major composite sponsor Boeing’s Sydney facilities we decided our best option for cooking the new top shell would be to build our own oven. In between all the laying of small parts (thanks to the expert training from Cam and Luke) the construction of our BIG oven has also progressed under the guidance of Jono and Jaga. For now it looks much like a large chicken coup but I am assured that by the time the team is ready to move on to the larger parts that it will be all systems go.
Progress on smaller parts is going faster than expected and as I write I’m sitting up in the FREEEEZING workshop waiting for our first part to cure properly after under cooking it slightly in our first attempt! (Personally, I can’t wait until they crank up the oven in here, about time I could stop seeing my breath inside!!!)
Mould preparation for layup
Tomorrow promises to be an action packed day, there are parts queuing up and many eager hands available and ready to practice their composite skills. With the fridge fully stocked with food to fuel the masses tomorrows BBQ promises to be a good opening to a big next week.
With 2011 World Solar Challenge fast approaching work in the workshop has intensified.
Today new team members started preparing the workshop for the massive amounts of composites work we will have to do in order to get a new top shell and array built in time for The Race this October.
The team build the oven for cooking Ivy's new top shell.
Today was the first Tuesday of UNSW Winter Holidays, and the team was hard at work. The composites room was cleaned. Aluminium plates were cleaned and prepared for practice carbon fibre layups. And an oven was constructed in the middle of the workshop. This oven will be used to cook the new top shell for Ivy.
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Hey all,
This is a new post to let everybody know that we will be letting everybody know what’ve been up to very soon 
UNSW is in week 11, which means exams, assignments, and less time for Sunswift as we’d like. The good news is that we’ve been quiet about a lot of really awesome thing’s we’ve been up to the past 4 months. In the next couple of weeks we’ll slowly start revealing where we’ve been up to, and what we’re working on now.
But for a brief outline: we’re working on completely refreshing our entire electrical system, with a focus on accuracy and reliability. Testing, and training, is our priority for the next 3 and a half months in the lead up to WSC11, and we’re doubling up on everything.
Stay tuned, and don’t forget to follow us on twitter and/or like us on facebook.
Regards,
Dan
