BVS at the Green Power Corporate Challenge
Posted: Tue Apr 29, 2008 11:46 am
Over the last three weeks I've been working with John Lilly on an electric race car that was to be the Battery Vehicle Societys first entry to the corporate category of the Green Power electric car race for schools. The idea of the event is to see who could go the furthest on the regulation motor and two sets of regulation batteries in four hours. Its aimed at school children from 9 to 21 years old but there are various age categories and once a year corporate vehicles are allowed to race the best of the school winners so as you can imagine the competition is very tough. I'm serious, they had to alter the regulations because some of the cars started averaging over 50mph from the same power motor and batteries that push your disabled granny around the shops! so this year they banned totally enclosed body shells to slow them down a bit.
More about the races at http://www.greenpower.co.uk/
As I was involved it naturally turned into a rat car very quickly. It was built entirely by John and myself out of scrap bits in six days in the three weeks leading up to the race but we also had a lot of help on the day before race day from Kelvin who spent hours mending punctures and Gadget who got the fiddly brakes working. We got all the bits assembled and had it rolling but untested at 4am and a mear 4 hours before scrutineering started. I did almost all of the constructional work whilst John prepared the bits for next step as he also had most of the ideas. He'd been trying to organise a team for a year and I got involved exactly a month before the race and in just enough time to lash an entry vehicle together. There was some confusion over who was supplying some efficient wheels which left us hunting out suitable replacements a week before race day and some vintage motorbike and BMX wheels were rapidly found. Over the six day build in the three weeks leading up the the race day we successfully welded together an abortion of parts into an electric racing car that got the approval of the scrutineer (who was a very nice man) and raced it around Goodwood racetrack last Sunday. After an initial chain alignment problem lasted the rest of the 4 hours endurance / distance race without major problems.
The machine was a Frankensteins abortion of parts most notably...
Two kiddies bike rear ends, both from skips,
The rest of the kiddies bike frames cut up and used for bracketery,
A broken childrens climbing frame pinched from a neighbours garden,
A Sturmey Archer 3 speed bicycle hub gearbox,
A second-hand microlite body shell,
More cable ties than you can possibly imagine,
A sack truck handle,
Some office chair legs,
A pair of car rear view mirrors,
Some impact foam scrounged from another team on race day - regulations I'm afrade.
A 3 point racing harness covered in mould and bird poop - Should have been a 4 point harness but the scrutineer was a very nice man.
Two old c90 (?) wheels with mis matching tyres that were about 35 years old and VERY old looking and cracked and were a bit larger than regulation allowed - did I say how nice the scrutineer was.
And of course the regulation unmodified 24V 240W motor and batteries.
Instrumentation was a bicycle speedo that gave random speeds but the clock worked which was very useful for timing laps and changing driver at agreed times and at the speeds we reached seconds weren't so important to us . An accurate ammeter was used to keep a note of current and allow control of motor temperature. A temperature gauge on the motor because over 80Deg C the glue holding the magnets would allegedly fail and destroy the motor. Control was via a microswitch cable tied to the steering wheel that operated a large contactor.
This is the drive train that consisted of a pair of kiddies bike pedal sprockts, a Sturmey Archer 3 speed hub as a geared lay shaft driven from the regulation motor. The Sturmey Archer geared hub gave ratios of about +33% 1:1 and -33% and were essential to get up the hills around the track. It was very successful despite failing some 200 yards from the start line and us being the first to be recovered by the recovery trailer. However some more bits of chair leg and some quick welding to brace the motor mount and keep the chain in alignment had us back in the race within 15 mins.
The steering bits were from some failed electric project from years ago. It originally had some new 26 inch wheels and braked hubs but those wheels had to be abandoned after we checked the rules that stipulated a max wheel size of 20 inches. Even though we used 17" motorbike wheels the overall diameter was more than 20" but as I have already said the scrutineer was a very nice man.
Did I say how nice the scrutineer was.
The finished thing, with John in the driving seat, Kelvin sporting his pink sleeved faded hang gliding suit and Mike the head scrutineer who spent much time reminiscing about how all the cars were like ours when the event was first started.
Queuing up for the start line. The wheels only went on the car at 4am that day and the only time it had driven under its own power was from the paddock to the scrutineering bay which was about 25 yards.
On the start line with Kelvin being the designated pusher as you are allowed a two step push start. I was able to get this close because I had to sprint onto the start line with a spanner and two forgotten 8mm nuts for the track rod ends and took the photo whilst retreating under the protest of angry marshalls
Some of the other marvelous machines.
Some more marvelous machines.
The day was not without excitement as several cars spun out exiting the bendy bit. This one rolled on its first lap and I believe another one lost a wheel after a spin and was the only car to retire from the race.
There were many cars there that ranged from one that Bently made that cost them £80000 not including labor and design time of their trainees to one (above) from the Blue Peter team (I'm trying to find when they are going to air the race on the TV show)
This me passing the finishing line. The girls are grinning like idiots because we were the slowest car in the whole race and actually passed the finishing line almost 15 mins after the race had officially ended due to a binding brake and resulting over heated motor and lack of power. The bored commentator had kept him self amused during this time by winding everyone up to the point that ensured a heroes cheer from the spectators when the finish line was eventually crossed at a snails pace
Anyway you're probably wondering about the results. Well considering we built the beastly thing in 6 days I was surprised it lasted the full 4 hours of the race and was still working well at the end of the race. But predictably we came last with the second to last being almost twice as fast as us and was being driven by a team of 13 year old girls !
The fasted lap time was about 3 1/2 mins which was an average speed of about 40mph and the max total distance in the four hour race was 122 miles or 51 laps. We on the other hand had an average lap time of about 12 mins which gave us an average speed of about 12mph and a total distance of 36 miles or 15 laps.
More results at.
http://www.greenpower.co.uk/racing/results_detail.php?type=2008_THECORPORATECHALLENGE2008_372248
It was interesting that we used less than half the battery capacity in the race but we were limited to how hard we could run the motor because we didn't have motor cooling and overheating would have resulted in instant failure, a fate of so many other earlier race cars and looking around the paddock most of the teams have rather elaborate cooling apparatus on their motors. So theres scope for more power and vehicle refinement even if theres a small budget available for next year.
Considering that we had no motor cooling, the tracking was out and we had just about the most inefficient tyres possible I consider the whole thing a total success despite coming last.
The main highlight of the day was receiving a surprise trophy for Innovative Use of Recycled Materials! The category was introduced this year by the IoM3 at the last moment and we had no idea that it existed until the prize ceremony.
I'm already looking forward to being involved in next years race when hopefully we will have a stronger team and a more competitive vehicle.
More about the races at http://www.greenpower.co.uk/
As I was involved it naturally turned into a rat car very quickly. It was built entirely by John and myself out of scrap bits in six days in the three weeks leading up to the race but we also had a lot of help on the day before race day from Kelvin who spent hours mending punctures and Gadget who got the fiddly brakes working. We got all the bits assembled and had it rolling but untested at 4am and a mear 4 hours before scrutineering started. I did almost all of the constructional work whilst John prepared the bits for next step as he also had most of the ideas. He'd been trying to organise a team for a year and I got involved exactly a month before the race and in just enough time to lash an entry vehicle together. There was some confusion over who was supplying some efficient wheels which left us hunting out suitable replacements a week before race day and some vintage motorbike and BMX wheels were rapidly found. Over the six day build in the three weeks leading up the the race day we successfully welded together an abortion of parts into an electric racing car that got the approval of the scrutineer (who was a very nice man) and raced it around Goodwood racetrack last Sunday. After an initial chain alignment problem lasted the rest of the 4 hours endurance / distance race without major problems.
The machine was a Frankensteins abortion of parts most notably...
Two kiddies bike rear ends, both from skips,
The rest of the kiddies bike frames cut up and used for bracketery,
A broken childrens climbing frame pinched from a neighbours garden,
A Sturmey Archer 3 speed bicycle hub gearbox,
A second-hand microlite body shell,
More cable ties than you can possibly imagine,
A sack truck handle,
Some office chair legs,
A pair of car rear view mirrors,
Some impact foam scrounged from another team on race day - regulations I'm afrade.
A 3 point racing harness covered in mould and bird poop - Should have been a 4 point harness but the scrutineer was a very nice man.
Two old c90 (?) wheels with mis matching tyres that were about 35 years old and VERY old looking and cracked and were a bit larger than regulation allowed - did I say how nice the scrutineer was.
And of course the regulation unmodified 24V 240W motor and batteries.
Instrumentation was a bicycle speedo that gave random speeds but the clock worked which was very useful for timing laps and changing driver at agreed times and at the speeds we reached seconds weren't so important to us . An accurate ammeter was used to keep a note of current and allow control of motor temperature. A temperature gauge on the motor because over 80Deg C the glue holding the magnets would allegedly fail and destroy the motor. Control was via a microswitch cable tied to the steering wheel that operated a large contactor.
This is the drive train that consisted of a pair of kiddies bike pedal sprockts, a Sturmey Archer 3 speed hub as a geared lay shaft driven from the regulation motor. The Sturmey Archer geared hub gave ratios of about +33% 1:1 and -33% and were essential to get up the hills around the track. It was very successful despite failing some 200 yards from the start line and us being the first to be recovered by the recovery trailer. However some more bits of chair leg and some quick welding to brace the motor mount and keep the chain in alignment had us back in the race within 15 mins.
The steering bits were from some failed electric project from years ago. It originally had some new 26 inch wheels and braked hubs but those wheels had to be abandoned after we checked the rules that stipulated a max wheel size of 20 inches. Even though we used 17" motorbike wheels the overall diameter was more than 20" but as I have already said the scrutineer was a very nice man.
Did I say how nice the scrutineer was.
The finished thing, with John in the driving seat, Kelvin sporting his pink sleeved faded hang gliding suit and Mike the head scrutineer who spent much time reminiscing about how all the cars were like ours when the event was first started.
Queuing up for the start line. The wheels only went on the car at 4am that day and the only time it had driven under its own power was from the paddock to the scrutineering bay which was about 25 yards.
On the start line with Kelvin being the designated pusher as you are allowed a two step push start. I was able to get this close because I had to sprint onto the start line with a spanner and two forgotten 8mm nuts for the track rod ends and took the photo whilst retreating under the protest of angry marshalls
Some of the other marvelous machines.
Some more marvelous machines.
The day was not without excitement as several cars spun out exiting the bendy bit. This one rolled on its first lap and I believe another one lost a wheel after a spin and was the only car to retire from the race.
There were many cars there that ranged from one that Bently made that cost them £80000 not including labor and design time of their trainees to one (above) from the Blue Peter team (I'm trying to find when they are going to air the race on the TV show)
This me passing the finishing line. The girls are grinning like idiots because we were the slowest car in the whole race and actually passed the finishing line almost 15 mins after the race had officially ended due to a binding brake and resulting over heated motor and lack of power. The bored commentator had kept him self amused during this time by winding everyone up to the point that ensured a heroes cheer from the spectators when the finish line was eventually crossed at a snails pace
Anyway you're probably wondering about the results. Well considering we built the beastly thing in 6 days I was surprised it lasted the full 4 hours of the race and was still working well at the end of the race. But predictably we came last with the second to last being almost twice as fast as us and was being driven by a team of 13 year old girls !
The fasted lap time was about 3 1/2 mins which was an average speed of about 40mph and the max total distance in the four hour race was 122 miles or 51 laps. We on the other hand had an average lap time of about 12 mins which gave us an average speed of about 12mph and a total distance of 36 miles or 15 laps.
More results at.
http://www.greenpower.co.uk/racing/results_detail.php?type=2008_THECORPORATECHALLENGE2008_372248
It was interesting that we used less than half the battery capacity in the race but we were limited to how hard we could run the motor because we didn't have motor cooling and overheating would have resulted in instant failure, a fate of so many other earlier race cars and looking around the paddock most of the teams have rather elaborate cooling apparatus on their motors. So theres scope for more power and vehicle refinement even if theres a small budget available for next year.
Considering that we had no motor cooling, the tracking was out and we had just about the most inefficient tyres possible I consider the whole thing a total success despite coming last.
The main highlight of the day was receiving a surprise trophy for Innovative Use of Recycled Materials! The category was introduced this year by the IoM3 at the last moment and we had no idea that it existed until the prize ceremony.
I'm already looking forward to being involved in next years race when hopefully we will have a stronger team and a more competitive vehicle.