My Electric (BEV) Mehran Project

[psyb0rg]

@frk2, I was just going to post about the steam idea. That, I too, think is the most economical way to start. You can have small 'plants' with large lenses and water pipes to create steam.
Windmills and solar panels come down the line but we should have a clear picture of the future if we want to build it

[psyb0rg]

And about the funding source, good luck

[OptimusSS]

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[sarmadqureshi]

@farazarif - Dude you need to change your pic the 88 LC is no longer your love. The fiberglass body make sounds like a EXCELLENT idea. I can then simply take a mehran chassis and have a nice sexy fiberglass body made for it. Do you have a contact? Is this the complete body (like the ENTIRE tub/cabin?) That would be extremely cost effective and light weight. I wonder what he does about the doors and the hood / etc ?

Mehran, is unibody cocoon shell. No separate chassis so you'll have to cut off the unwated areas for your fiber body + who is going to design it ? In the end you dont want your creative process going down the drain just because the car looks like a tram.

I'm sure you must have seen those chinese cars & know their fate....at a showroom opposite Avari...

[psyb0rg]

There is a guy here https://www.pakwheels.com/forumreply_az_TopicID!56337~ForumID!6~Page!406~pw.html&#reply who makes fiber glass bodies. I contacted him exactly because future electric cars need to be light and we should be able to make them locally.

[jabbar81]

I read somewhere in ur post about "gear assembly". Why r u using such thing?

Is ur drive is direct motor drive? which mean motor attached with each wheel.

Whats ur highest qualification. If u r interested u can do a same project as a PHD project with Dr. Farrukh Kamran at CASE, Islamabad.

[psyb0rg]

@jabbar81, you need a kind of a gear box to transfer power from motor to wheels and to control the rpm, just like in a normal car. That's why it would be cost effective to use Mehran's gearbox, if it fits, which frk2 says it does.

[frk2]

hahaha most hated? Its like the most popular car in the country (its a VERY popular car in here and india even by world standards)

[frk2]

psyb0rg - when you do custom stuff nothing fits. I had to fabricate a adaptor plate (die cast aluminum) to mate the motor firmly with the flywheel assembly. The gearbox lets me run the motor at low rpm (Less amps -] more efficiency -] more battery life). Since this is a DC torque motor it cannot run at high revs (max rpm : 6000). Some EVs have A/C motors which can do 15000 rpm safely and they dont really need a gearbox - a simple reduction gear is enough. However, they require a DC to AC convertor and a A/c Drive motor controller both of which are quite expensive. I personally prefer anything DC to AC (as I'm more of a digital and less of a analog guy! )

[frk2]

@sarmadqureshi - I didnt realize the mehran was a unibody. that is bad news. But its a concept car so looks dont matter I guess. If I do commercialize then it will have to be a cool looking lightweight body. Small chassis, gears, axles, kamanis can all be imported from china if need be (or built locally). For such a light car even a Tubular frame with a fibreglass body would suffice.

[psyb0rg]

(Y)

Think about this: put a 70cc bike engine in your car, connected to an alternator to charge the batteries and you got yourself a hybrid.

[jabbar81]

This transfer mechanism using the gears etc is not efficent in Electric vehicles , its more useful in hybrid cars.

Best technique is that all wheels are separately driven with motors directly attach with wheels, 4 motors. This will allow techniques which you can serach by internet for braking and reduction in power consumption. This technique also results in low weight. And drive will be like a fly-by-wire.

F Caricchi, F Crescimbini, O Honorati,
Compact wheel direct drive for EVs,
IEEE Industry Applications Magazine, 1996

CC Chan, YS Wong

Electric vehicles charge forward.

• IEEE Power and Energy Magazine, 2004

[frk2]

@Jabbar81 - I am a double major in EE and Computer science from Cornell, NY. I would love to build another prototype and test proper specifications if the Phd study can fund the next car. However, I warn you that I am not terribly good with paperwork and prefer real world action over theory any day

What would be the scope of the Phd study?

[psyb0rg]

@jabbar81, more motors, higher cost, increased complexity of controlling the motors and syncing them.

[frk2]

@jabbar81- CAn you state why exactly it is not efficient? There is no loss or minimal loss of mechanical energy going from the motor to the wheels. Hub motors theoretically may make more sense but you have to realize what is more practical given the technology today. Gear / Axle technology is dirt cheap. It is far less complex/cheap to control a single large series wound torque motor than 4 individual motors (and allow for limited slip/etc).

My idea is to commercialize this for the masses - cost, practicality and available technology plays a very important role. How would you install these hub motors on existing axles? Im particularly interested in real 'live axles' of most small cars.

[bnasir]

FRK2 - I am giving you a standing ovation!! Clap Clap Clap. Can't wait for you to finish it and put it on the road. Fantastic. Great work!

[frk2]

@bnasir- thanks man. But the real fun would be if it can be cost effective for mass use. Otherwise its just a crazy experiment which no one benefits from.

[jabbar81]

frk2
: If u like ur car to really work, u need to amke some practical decision. I ahve bacholar degree in Mechatronics from NUST, 2002. I did my MS from korea, 2008, i have practical work experience in robots, IC designing and digital communication. I have seens cars here both hybrid and electric driven and have discussed the mechanism with people who have build them.

I think ur car is only electrical driven, surly it will move the way ur doing, but at end it will all come to the battery power and speed. As a first prototype u can go ahead, if u want to make something awsome and contribute towards technical knowledge, try to make it direct drive. This will require developing a fixture for mounting, motor control, and money.

I donnot know exact statenet of project, but its Dr, Farrukh favourite project he want to undertake, no one is willing so far. He taught us Power electronics in undergrad and still looking for someone wo can do teh projec. He wants to design a Motor which can be mounted directly on the wheel, u need to work in ANSYS for electromagnetic analysis and build some controller for drive. I am hopeful he can arrange the funding.

[psyb0rg]

Guys, check out this setup:

[frk2]

jabbar81: Please do introduce me to him, always willing to learn. My aim is not technological superiority but rather building a mass market indigenous electric car. I can build an awesome pocket rocket which goes 300 miles on a single charge right now but it would require bill gates to buy it. Designing a motor is tough business - specially when its not the problem. Nobody in the EV world says the motor is the bottleneck. If he wishes to design a Better, cheaper battery that would be quite interesting.

Why design a new motor when the world agrees that motors are not the bottleneck? Current motors are over 90% efficient. Motor to each wheel would be cool but it would be like having four engines. Controlling slip and calibrating each motor on each turn would be a computing nightmare!!!

Ps: No EV today either commerical, concept or hobbyist uses direct drive hub motors. They all have singly mounted torque motors with either a automatic gearbox, a CV gearbox or a single differential reduction gear in the case of A/C motors. Hub motors are a engineering challenge as they need to be tiny and pack the same puch large series wound motors too. Why bother I say?