After reading Tuarn's post in the AEVA forum I got thinking more about lowering the rolling Resistance.
I had considered these ideas at different times but Tuarn rolled them up into one nice post.
Lower viscosity oil in the diff will be a must. As per Tuarn I will look for 55W75.
Setting the tow in will be important. Lower the better within reason.
Tyre pressure is a given. I will try and locate the Rolling Resistance specs for my tires.
Now the tricky part. How do you minimise brake drag. The rear drums are self adjusting and the front are disk brakes. Neither lend themselves to tweaking. Any tips and suggestions welcome.
At some point I will get some 'moonie' hub caps / wheel covers. Partly to reduce wind resistance and partly for looks.
Thursday, 29 May 2008
Update - Batteries - Tester - Diff - Steering - VFD - Tray
It has been a few weeks since my last post so an update is in order. photos to follow.
1. I received the Greensaver batteries (20ah and 27ah - 2 hr rate). The port chargers were unbelievable! These would have to be the 2 most expensive batteries in Australia! Lesson learned about sea-freighting goods
2. I have built a micro controller based charger / discharger. It will measureand log to a PC the following aprameters during discharge and charge Volts, Amps, Watts, Ah, Wh, temperature and the all important Peukert factor. It uses 4 x 1 ohm resistors. The resistors can be wired differently to vary the test current. I am waiting an LCD from Futurelec and a charger from ebay's ecrazyman.
3. I have bought a diff from pick'n'payless . It is a 5.125 ratio from a Hiace van. All going well I will install it this weekend. This gives a theoretical top speed of 94km/hr at 4000RPM
4. I also bought a manual steering box from pick'n'payless for installing this weekend.
5. Better VFD. I bought a better Danfoss 5042 VFD off ebay. So, if anyone wants a Danfoss 6042VFD in an IP54 case I have one looking for a home. I have removed all the AC components from the cabinet to minimise losses and will feed it DC directly to the soft charge circuit.
6. The ute has a tray back which was way too wide for the body. To tidy up the looks I have narrowed the tray to be the same as the body (100mm off each side) and shortened the back. If I need sides I can get them from the manufacturer which is encouraging.
At the moment the carport looks like a car wreckers yard, but things should start coming together in the next few weeks. I am still waiting to borrow an engine hoist from my neighbours.
1. I received the Greensaver batteries (20ah and 27ah - 2 hr rate). The port chargers were unbelievable! These would have to be the 2 most expensive batteries in Australia! Lesson learned about sea-freighting goods
2. I have built a micro controller based charger / discharger. It will measureand log to a PC the following aprameters during discharge and charge Volts, Amps, Watts, Ah, Wh, temperature and the all important Peukert factor. It uses 4 x 1 ohm resistors. The resistors can be wired differently to vary the test current. I am waiting an LCD from Futurelec and a charger from ebay's ecrazyman.
3. I have bought a diff from pick'n'payless . It is a 5.125 ratio from a Hiace van. All going well I will install it this weekend. This gives a theoretical top speed of 94km/hr at 4000RPM
4. I also bought a manual steering box from pick'n'payless for installing this weekend.
5. Better VFD. I bought a better Danfoss 5042 VFD off ebay. So, if anyone wants a Danfoss 6042VFD in an IP54 case I have one looking for a home. I have removed all the AC components from the cabinet to minimise losses and will feed it DC directly to the soft charge circuit.
6. The ute has a tray back which was way too wide for the body. To tidy up the looks I have narrowed the tray to be the same as the body (100mm off each side) and shortened the back. If I need sides I can get them from the manufacturer which is encouraging.
At the moment the carport looks like a car wreckers yard, but things should start coming together in the next few weeks. I am still waiting to borrow an engine hoist from my neighbours.
Monday, 12 May 2008
Tray off and ICE ready for removal
I have removed all things petrol from the vehicle and am ready to lift the engine out as soon as I get the hoist from my neighbour.
The brakes look OK. The diff needs replacing. Just as well I planed to change it to a lower ratio.
The next few weekends will be spent fixing up the body paintwork and surface rust spots.
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The brakes look OK. The diff needs replacing. Just as well I planed to change it to a lower ratio.
The next few weekends will be spent fixing up the body paintwork and surface rust spots.
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Friday, 2 May 2008
Band I just found - Abney Park
I just found this Steampunk band called Abney Bark.
here is their album to play while you read :)
here is their album to play while you read :)
Monday, 28 April 2008
Greensaver batteries on order
I have ordered some sample Greensaver batteries. A 20AH, a 27Ah and a 12 volt charger.
I have also ordered 4 x 1 ohm 200w resistors for building a battery analyser. I am workon on the Bascom AVR code at the moment to check their capacity at different loads. The Peukert fact er of 1.09 for the 20Ah unit seems a little too good to be true but if it tests out after many cycles then they are great value for a bit over USD20.
I have also ordered 4 x 1 ohm 200w resistors for building a battery analyser. I am workon on the Bascom AVR code at the moment to check their capacity at different loads. The Peukert fact er of 1.09 for the 20Ah unit seems a little too good to be true but if it tests out after many cycles then they are great value for a bit over USD20.
Wednesday, 23 April 2008
Speedo
I have been browsing the workshop manual for a 93 Hilux / Tacoma and checked the vehicle and it has an electronic speedo. This is brilliant because I wont have to retrofit one.
The speedo just requires a 4 pulse per revolution input from the shaft.
There is a pulse output from the Danfoss VFD that is programmable. I will also be able to adjust the VFD output to compensate for the change in differential ratio.
This setup will require that I use closed loop control to have an accurate speedo.
The speedo just requires a 4 pulse per revolution input from the shaft.
There is a pulse output from the Danfoss VFD that is programmable. I will also be able to adjust the VFD output to compensate for the change in differential ratio.
This setup will require that I use closed loop control to have an accurate speedo.
Monday, 21 April 2008
Vehicle Purchased!
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I have finally purchased a vehicle for the conversion.
It is a '92 Extra Cab Toyota Hilux ute (Tacoma Pickup for our American viewers). Model is a RN90R.
The good:
The right price for Sydney. These vehicles are about $2000 more expensive in Sydney. I payed $4k for it. The body is straight apart for a ding on one guard.
The interior is in good condition apart from the drivers seat that will need replacing.
The Bad:
It looks like it is from Mad Max as it has been painted black and has very dark tinted windows
The tray has no sides
The black respray is peeling off in places.
It has done 330,000km so I can not really sell the motor
To Do:
Replace drivers seat and various trim pieces inside.
Remove interior for cleaning. (I did this on the weekend. I just need to wash the carpet.
Investigate re-paining the body white or touching up bad paint job.
I took it to the local tip to put on the scales. The kerb weight (no driver or fuel) is 1250kg. A little more than I expected as it has an aluminium tray back rather than a well side. The GVM is 2050 allowing 800kg of load.
The rear axle has 41% of the weight. I will mount the motor as far forward as practical in order to maintain the balance.
I would still prefer to remove the gearbox. There is a 5.29 ratio differential available (existing is 4.1) from an early Hiace. This would give a final drive ratio a little high than third which may be acceptable. The top speed would be about 80km/h which is adequate for me.
Saturday, 5 April 2008
Battery Balancer
I have been thinking about how best to balance my chain of batteries, all 50 of them.
As there are 50 units the price could be quite significant.
Ideally a microprocessor based system would be implemented with isolated sensors on each battery however at this time it is cost and time prohibitive.
There are 2 alternatives I have seen the first would place 15V Zener Diode in series with a light bulb or suitable resistor across the battery. When a battery exceeds 15 volts, the Zener and lamp would bypass current proportional to the over voltage. This would be the simplest to implement.
Another alternative is a more aggressive voltage clamp described here.
The clamp voltage will have to be above the maximum charge voltage from the chargers and the regenerative braking.
Under regen this is 15 volts. Under charge this is about 15 volts but will need to be measured on the charger.
Obviously this solution will only work under charge but should be sufficient for now.
I will test it on my self balancing scooter first.
As there are 50 units the price could be quite significant.
Ideally a microprocessor based system would be implemented with isolated sensors on each battery however at this time it is cost and time prohibitive.
There are 2 alternatives I have seen the first would place 15V Zener Diode in series with a light bulb or suitable resistor across the battery. When a battery exceeds 15 volts, the Zener and lamp would bypass current proportional to the over voltage. This would be the simplest to implement.
Another alternative is a more aggressive voltage clamp described here.
The clamp voltage will have to be above the maximum charge voltage from the chargers and the regenerative braking.
Under regen this is 15 volts. Under charge this is about 15 volts but will need to be measured on the charger.
Obviously this solution will only work under charge but should be sufficient for now.
I will test it on my self balancing scooter first.
Thursday, 3 April 2008
Greensaver Silicon batteries
Thursday, 13 March 2008
Updated - The gearbox will stay / Go.
I now have a better VFD and have a 5.125 ratio diff so I will no longer need the gearbox!
[I made a design decision that the gearbox will stay in the build unless I can get a more powerful motor controller. ]
I don't think the one I have will provide sufficient power for a standing start.
Gas less MIG: I am thinking of buying a Gas less MIG welder to do my own welding. I will have to be sure this is allowed by the engineering inspector.
[I made a design decision that the gearbox will stay in the build unless I can get a more powerful motor controller. ]
I don't think the one I have will provide sufficient power for a standing start.
Gas less MIG: I am thinking of buying a Gas less MIG welder to do my own welding. I will have to be sure this is allowed by the engineering inspector.
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