Choice off controller

In order to control the electric motor we need a controller. In its most basic form it interprets actions taken by the driver and adjusts the voltage and current to the motor accordingly. There are as many flavors of controllers as there are types of motors. A good source for finding motors and controllers that work together is www.evalbum.com.

When choosing controller you should, at least, consider the following.

·        Make sure the controller matches your type of motor, DC, AC, series and so on.

·        Make sure the controller can provide the amount of power you need for your application

·        Make sure that the controller is easy to program and that there is some kind of support mechanism that can help you if you get stuck.

I've used the Controllers from Sevcon and Kelly and its two different worlds. First of all the Sevcon Gen4 controller is AC and the Kelly is DC.

Sevcon Gen4 G4845

. Apart from that the Sevcon controller is a state of art controller with more settings than you can ever imagine. On the down side the complexity makes is very hard to program and even if you are a dealer it can be hard to get support from Sevcon. On top of that the programming interface for the Sevcon Gen4 controller costs about $900!!!

The IXXAT 1.01.0087.10200 used for programming the gen4.

Kelly on the other hand uses a USB-to-rs232 cable that you can find in any computer store to program their equipment. Kelly's downside is, if you should believe the word on the internet, their quality. I've never heard so many bad words being said about any controller/manufacturer. I didn’t really choose Kelly, it came with the motor. But I will give them an honest try. I've already started by contacting support and they answer back in a day or two.

The problem I'm facing is that the red led on the controller is on all the time. According to the manual this means that is broken but it seems to be working quite ok. I've put together a document with pictures of the controller and schematics showing how it is connected. It has all been sent to Kelly for review. Programming of the controller is done via a GUI that runs on Windows. In order to communicate with the you need the USB-to-rs232 interface. According to Kelly all external devices, such as motor, throttle should be disconnected during programming of the controller. You don’t actually need the batteries connected as you can supply the controller with a minimum of 18 volts via J1. J1 is one of the two round connectors on the front of the controller. I hooked up a PC-supply to pin 1 (+) and pin 13 (-).

Apply power and connect the db9 connector to the controller. Make sure that you have already installed drivers for the USB-to-rs232 in windows.

The controller should, when booting up, turn on the green and the red led, after a few seconds the red one should turn off.

Start the programming software, you can get it from http://kellycontroller.com/support.php make sure you pick the right software for your controller.

I should mention that this is work-in-progress and all of the settings described here might not be 100% accurate. In other words, don’t blame me if something goes wrong. ALWAYS keep your car jacked up during testing.

This is the first window that pops up after starting the application. I'm going for a basic configuration using a 0-5v throttle as the only external device. The throttle gets 5v from the controller and by moving the lever it returns 0.9-4.10 volts to the controller. The controller also includes a micro switch but we will get to that later.

First of all I specified the throttle effective starting position to 1.2 volts. This means that that the controller won't send anything to the motor if the value from the throttle is under 1.2volts. I l left the throttle effective area end position at 4 volts.

Maximum motor current specifies the maximum current that will be sent to the motor. The value is a precentage of the total current handled by the controller. The 72601 can handle 600 Amps and the Agni has a maximum apm of 300, hence the 50% setting.

! Make sure your battery pack can supply the current specified !

On the second page we will set over and under voltage. These setting are important and will protect your battery pack. These values vary depending on the battery technology used. Get the right setting from your battery supplier.

Another setting on page two is control mode this is how your controller should behave during acceleration. I've always been told to use torque and not speed. Kelly introduces  balanced and I'm guessing I will play around with these values later.

Throttle up/down rate determines how fast the controller should respond to the throttle signal

This is cool stuff, regen, regeneration of energy. Imagine that you are out driving and you run up on a red light. In order to stop you depress the brake pedal. A "normal" car does not have any means of recovering the energy generated during this phase. All the energy that kept the car moving before you pressed the brake is turned into heat. The good thing with an electric motor is that it can be turned into a generator and if your controller supports it the energy from the moving car can be returned to the battery pack instead of going up in smoke. At least that’s the theory of it.

Regen can be controlled in more than one way on the Kelly. I'll start with the simplest setup. When you step of the gas pedal regen will start! This might not be the best solution because it might be wiser to let the car freewheel down a slope then to try and capture the energy generated.

So I found out that if you connect the micro switch in the throttle to the controller you can actually decide if you want to start regen or if you want to freewheel. It works like this:

When you want to use regen you step of the pedal, but not all the way. The trick is to keep the micro switch connected.

If you want to freewheel down a long slope you let the pedal go to its starting position, which means the micro switch will be disconnected. This will deactivate regen.

See http://youtu.be/fEPFgumcJDM for more info.

When you are done with the configuration, click Finish and power-cycle the controller.

Out with the old and in with the new!

Hi again! I've started to remove the I.C.E and it's components from the car. It's a pleasure to work with the car since everything is clean as a whistle. First of all I removed the I.C.E. This can easily be done without removing the gearbox. I tried to determine the weight if the I.C.E but the scale only ran to 50Kg, I'm guessing 55-60kg.



Clean soon to be green machine!

The gearbox is ready for its new motor. I will pick it up from my mechanic this Friday. I'm thinking about plugging the hole for the starter but then again it might be good to get some air in there. The clutch will handle a lot more power with the Agni. Peak torque is about 53 Nm.



This is the clutch disc I use its for 500R/126.



This is the surprise of the day! There is a voltage regulator mounted on the left side in the engine compartment. I won't be using it so I removed it today. As I held it in my hand I noticed the resemblance between it and the pedal throttle I bought from Kelly.



Voltage regulator used to monitor charging of the 12 volt battery



Pedal throttle 5v



It turns out the bolt pattern for the two are the same! So I mounted the new throttle where the voltage regulator was once mounted and then, since I don’t want to alter too much on the car, I will connect the original wire to an lever mounted on the new throttle. Ecellent!



Electric throttle mounted where the voltage regulator used to be.

 It has finally arrived! Can't wait to get going. But now it's time to go for some salmon fishing! Have a nice weekend.

Time for a major milestone! The motor has been installed in the car and it has been tested, only with 12 volts, but it turns and the clutch works just fine. I've decided to mount the controller, main contactor and fuse above the motor. I cut out an aluminum plate that is held in place by vibration dampers. Since the Kelly controller is sensitive regarding temperature I will mount a fan or to on the controller.



The Agni in place!



35mm² cable capable of 72V 500A





!

 Some more work done today. As I said earlier the controller from Kelly needs some help to cool down. I've cut out an aluminum plate and used thermal paste between the plate and the controller. Two 120mm fans has been mounted on the controller to aid the cooling. The main contactor has been installed as well as the fuse. A thick rubber mat is used to shield the plate from the hi-power wires connecting to the controller.

Two 120mm 12v fans for extra cooling

Fuse, contactor and controller

Not to bad!

In the picture above the throttle and the lever has been installed. The lever is connected to the original wire for the gas pedal.





Gearbox adapter

So I've started to work on the adapter that will allow for the Agni 95-r to be mounted on the gearbox. There are some tricky part that needs to be solved. The flywheel has been modified and it's now 15,5 mm thick and has a diameter of 208,80 mm. The diameter is limited by the size of the clutch.

Gearbox bolt pattern and shaft

There is a pilot bearing in the crankshaft for the shaft coming from the gearbox, shown in the picture above. This bearing needs to be added to the new flywheel hub on the electric motor shaft.

Crankshaft and pilot bearing

I tried to reuse the hub on the crankshaft, by sawing it off, but the crank is hollow and there was not enough material in the hub to fasten it on the shaft of the electric motor.

New hub, lighter flywheel now we need to design the adapter. The adapter must retain the measurement given earlier in the blog regarding distance between flywheel and gearbox, 99mm.

First we will add 15,1 mm thick aluminum plate that contains the bolts that measure up to the bolt pattern on the gear box.

On that plate we will bolt a "ring" of aluminum that will hold the motor at a correct distance from the gearbox.

Agni, hub, flywheel and ring

One thing that we don't want to forget is that we need to be able to attach and remove the hub from the shaft of the Agni. In order for this to work we need a small "service windows" in the ring. The hub will be locked by two bolts aligned with the keyway.

Adapter ring with service window

14 kg of Aluminum has now been delivered and the work is about to begin.

This is the first picture of the adapter, looking good if you ask me.


Agni with adapter ring and modified flywheel



The adapter plate has now been modified so that the flywheel fits



Done! Now I need to get some strong bolts and start removing the I.C.E.

Here you can see the service window as weel as the bolts holding the motor, a very nice job

This is the plate that sits in between the gearbox and the adapterring

Modified flywheel with the new hub

Clutch mounted on flywheel.



Choice of motor

There is a jungle of electric motors out there DC, AC, Series DC, permanent magnet and so on. The choice of motor is critical so you should invest some time in it. The fiat 500 R has an 18hp 594 cm³ engine producing about 35 Nm at 3000 rpm, max hp at 4500 rpm.

The original I.C.E without the "shell"

Give the values above and the fact that I will be using the original gear box I started looking for a suitable motor.

A good place to start looking for a suitable motor is http://www.evalbum.com/. You can browse through cars and even find your car model already converted.  The reason for choosing Agni as the motor manufacturer is because of its low weight, high rpm and high efficiency. The only back draw would be that it’s not a brushless motor.

I’ve used motenergy’s (http://www.motenergy.com/) ME0201013001 in my boat and the ME0708 for my mower and they work fantastic. The reason for not using them on the fiat is the low rpm.

This are the specs of the Agni 95-R

· Hi Torque 8" Diameter motor

· Highest Power to Weight ratio

· Kevlar banded for higher RPM performance.

· Bi Directional rotation

· Adjustable Timing

· Easy brush maintenance

Model	rpm/V	max. V	A cont. @48V	cont. output power@48V	max rpm	cont. output power	max. power for 5sec
							kW
95-R	71	84	220	9.5 KW	6000	16 kW@78V	ca. 30 kW

Agni uses the following model to calculate the size of engine for a specific vehicle.

Take the weight of the vehicle, I use 600 Kg, and multiply it with the intended top speed, let’s go for 100 Km/h. This gives me a value of 60000. If the value is more than 30000 you will need a gearbox if it’s lower than 30000 you can go for direct drive.

I’ll use the gearbox on the fiat and the rule of thumb is:

When in top gear with a gearbox, the overall reduction ratio needed will be about 3.6:1 with typical size small car wheels (145/70x12, approx. 20 inches diameter including tires).  The fiat 126 gear box and the top gear ratio is 0,87:1 and the final drive ratio is 4,87:1.

Gear box with integrated final drive

Let's try some math!

The gear ratio on the 4th gear is 0,87:1. The Agni 95-R gives me 71 rpm per volt, I'm guessing this is during a no-load scenario. I will be using a 72 volt system which gives me 71*72=5112rpm 5112/0,87 equals 5875 rpm before the final drive ratio. Rear end gear ratio is 4,87:1 and tier diameter is about 20 inches. This boils down to a maximum theoretical speed of 72 Mph. 

The rpm/v will be lower when under load, approx 4800rpm, and the voltage will decrease during high ampere draw from the battery pack so I'm guessing I'll end up somewhere around 67 Mph.

Interior

What about the interior? The 500 has a simple but nice interior. The interior of the frame is painted with the same color as the exterior of the car, in my case dark blue. Door panels, seats and part of the roof are burgundy.

I wanted to do something about the front seats but I don’t want it to look like a cheap race car. I’ve looked at seats from the new 500 but they are very hard to get.

I would never ever put sparcos in my 500 that’s just rude. It needs a classic look period!

I wanted leather seats with a classic design and adjustable backrest for access to the rear seats. Ferrari would be nice but way out of my price range. Mazda Miata mx-5 has nice small seats but I had no luck getting those either.

What about Porsche? German seats in an Italian car? Someone is bound to be turning in his/her grave. Turns out Porsche seats, 911, are a perfect fit and I was lucky to get my hands on a nice pair in black leather with electric heating and power seat control.

Perfect match if you ask me!

Say what!?

The trees are dying, the water is polluted, the ice is melting, global warming accelerates and I have too much time on my hands not to act on it. I've always had a thing for mechanics and electronics and I love nature. During the last year I've converted my riding mower from I.C.E, Internal Combustion Engine, to electricity and my boat is now sporting a hybrid drive line designed and installed by me.

Everything started a few years ago after I sold an El Camino that I restored. I was so disappointed of the I.C.E's efficiency and wanted to do something that would have an impact on the foot print left by me in this world.

So let's cut to the chase! I'm converting a Fiat 500 R from 1973 from I.C.E to electricity. Why the 500? Well, first of all, it's the most beautiful car in the world. It's also a light car with very low drag coefficient drag coefficient.

Here's some data taken from wiki:

Manufacturer	Fiat
Production	1957-1975
Assembly	Turin, Italy
Predecessor	Fiat 500 "Topolino"
Successor	Fiat 126
Class	City car
Body style	2-door sedan 3-door estate
Layout	RR layout
Engine	479 cc I2 499 cc I2 594 cc I2
Transmission	4-speed manual
Wheelbase	1.84 m (72.4 in)
Length	2.97 m (116.9 in)
Width	1.32 m (52.0 in)
Height	1.32 m (52.0 in)
Curb weight	499 kg (1,100 lb)
Related	Autobianchi Bianchina
Designer	Dante Giacosa

We are talking about 500 kg's of steel driven by an air cooled I.C.E producing a maximum of 22 hp. It supposed to be a four seater, but I don’t know about that.

The picture shows the convertible but I have got my hands on the one with the sun roof. As you can see the car is a rear wheel with gearbox, engine, differentials and driveshaft all built into one unit mounted in the back of the car. The fuel tank is located in the trunk in front of the driver there is not really any space for luggage.

After a year of looking through car magazines and adds on the net i found a 1973 fiat 500 R in the outskirts of Stockholm. I went to see it and to my surprise the car was in great shape. The body had been restored, new floor pans, new doors, new hood and so on. The drive train was of unknown state but a working engine + gearbox was included in the buy.

So I ended up buying a grown man's LEGO. Thousand parts to play with. Perfect!

Love at first sight

Room for inspiration

Smelly!

The first thing that needed to be done was to remove the engine and to start to work underneath the car. Suspension arms, springs, breaks and shocks, everything had to be overhauled.

As you can see there was still some rust and dirt left underneath the car.



Fresh!



Turns out the engine had been overheated and it did not turn.



New adjustable shocks and some paint job. Looks as good as new.

I had a couple of hours left of my spare time so decided to restore the I.C.E just for fun. It's a shame it's such a polluter because it’s a nice little machine. The engine block fits inside a standard stove, but don’t tell Lisa about that.

Engine and gearbox ready to be fitted in the car

Lights installed. All light bulbs except head lights are LED's

Sun roof in place

Drivetrain in place

Work is easier when there is no rust

Test drive

So the drive train is in place and everything seems to be working, but wasn't this supposed to be a story about a conversion? That's right! The main reason for installing the original drivetrain was to get all the measurements correct.

The plan is to keep the gear box and the clutch but replace the I.C.E with an electric motor. I will keep the clutch and the flywheel.

The flywheel is situated 99mm from the gearbox. The adaptor plate between the electric motor and the gearbox needs to be designed so that this measurement is not altered.