/diy/ - Do It Yourself

Registration will be the tricky thing.

Yeah, I thought about that. What do you register it as? Kit car maybe?

4x brushless motors would make best off/on road

>>269606

Have anything in mind?

take a horse cart, replace horse with engine

>>269606
>electric just makes sense
what is harder to do hook up a fuckton of sensors for efi tuning and timing and maintenance? you gonna make an ecu or ecm or electric car would be cheaper make a range extender too if you would like

mark my words we are getting really close to this cus computers all you need is a little /diy/ knowhow and a computer these days and you can do just about anything

I say go for it!

>Am I wrong?
actually, yes

aside from the legalization of said vehicle (crash worthiness is probably the greatest sticking point, aside from scrutineering of the brakes, lights, steering, emissions, and so on...), you really need to coinsider the chassis as a whole. any engine/tranny combo you pull from another vehicle will be set up for that particular vehicle's weight and drive system. if you take the 7.4 liter diesel driveline out of my ford and try to put it in a 2000 pound lotus wannabe, your shift points and load characteristics will be horribly rough. then how do you decide on a suspension setup? weight alone is not enough to determine what works and what throws you into oncoming traffic.

and those are the basics. rest assured that the multitude of engineers at every auto manufacturer are indeed earning their keep. now go karts, on the other hand.....

>>269609

I agree, there's the argument of gasoline/diesel efficiency, but none of them come close to electric motors.

>>269607
yes I do

Motor Specs

Brushless Permanent Magnet AC Motor

- 4 pole motor (8 magnets).
- Phase to Phase winding resistance: 0.013 Ohms
- Maximum recommended rotor speed: 6000 RPM
- Voltage: 0 to 96 VDC input to the control
- Inertia: 45 Kg Cm Squared
- Current: 125 Amps AC continuous (180 Amps DC into the - motor control)
- Peak current: 420 Amps AC for 1 minute (600 Amps DC into the motor control)
- Weight: 35 pounds
- Peak Stall Torque: 90 Nm.
- Cooling: Open Frame, Fan Cooled motor.

P/N: ME0913


PMAC-DS 72/84V 550A
Brushless Drive Kit

56 HP pk.

http://www.electricmotorsport.com/store/ems_ev_parts_kits.php


agreed this is over the top @12k just for 4 motors and speed controllers not to mention batteries but you could make a quadcopter with this and fly yourself from place to place

or you could put one in a geo metro 1liter it matches perfectly for rpm as long as it is manual

>>269611
bluebook price geo metro 2-3k price of motor and speed controller 3k for batteries and charging system necessary mods .5k and your time totally road worthy car capable of going nearly 100(theoretically) and your time and effort 6.5k for the stuff plus your time and energy still sounds better than proprietary ecus and clever ways to lock you out of being able to interface with the car

cheapest 2012 us car Nissan Versa 1.6 S: $11,750

then again your time and effort is priceless

>>269613

electric is only slightly less retarded than hydrogen when compared to gasoline, diesel, or even natural gas.

based solely on the storage capacity alone, nothing comes close to gas and diesel. with about a hundred pounds of "oomph" either could take me 4-500 miles. electric? nope.

>>269612

There should be a PWM variant. Speed control could be easy then. 10% - 100% forward, 9% - 1% for reverse.

>>269614
how simple the motor is compared to an engine

you can breeze past a lot of regulations if you use a chassis off a real car

Also, what is the torque output right off the line? I like this idea.

>>269619

What if you modify the chassis? Cut and lower the roof for example. Cut the firewall to move the engine closer to the middle?

Or the batteries closer to the middle since we're on the topic of electric motors now.

>>269619
>>269616
>>269616
true lol like safety regulations for one lol

>>269619
not in the us
>>269620
torque off the line is useless unless you want to show off or are driving a train.
maintaining a high rate of speed while cruising? priceless.

>>269623

Torque off the line isn't totally useless. Pretty good for city/gridlock driving. No need to put a lot of strain on the motors if they're just not capable of handling it.

If your car can be labeled a kit car you can ignore a LOT of regulations. Granted there are specific regulations that still must be upheld and an inspector will determine if they have but it isn't as huge a hassle as trying to be a small output manufacturer.

>>269623

Yes in the US. So long as it's not ghetto-fab or otherwise falling apart it'll pass safety. If it's 25+ years old this becomes even more lax. Granted if you're in cali you're fucked.

ITT: people who have never done more modification than installing bolt-ons and who don't know the difference between HP and TW

How much power does it take to spin the AC compressor, oil pump, water pump, and power steering?

>>269610
Listen to this guy. Unless you know your engineering (not just ME btw) and have years upon years of time for development you should let go of that idea.

>>269600
TORQUE MOTHERFUCKER?

+1 CAT C27 engine
+1 custom quick shift CAT AD55 Rhino Automatic Transmission
+1 CAT AD45 Differential
+1 volvo 250 from the 80's
+4 big fucking wheels
+0 brains
+<9000 balls
+1boot sized fuel tank

100 k limit with the engine revving its tits off

protip: above components are designed to move 80+ tons of mining machine not a 82 volvo 250

>>269656
C27 IS rather large use a C18 as they weigh alot less

>>269621
the roof isn't apart of the chassis

>>269673
can be, depends on how the car was made.

as for modifying it, legally you should probably send it for some sort of single vehicle approval, but whether or not you actually need to do it is a different question

Things not yet mentioned in this thread that are also important
+ Suspension type for front and rear
+ Camber
+ Toe-in
+ Caster
+ Wheelbase

Building the frame of a vehicle from scratch involves knowing how to pick the angles and spacings for the above items to achieve predictable and stable handling at a given weight, speed, and power application. These numbers are important for even slow moving vehicles. A frame isn't something I would even think about making from scratch myself without having a decade or two of experience with the engineering involved.

Most people making an experimental car either buy a frame, or gut one from a vehicle they like the handling of. This also give you a legitimate VIN number with which to register the vehicle.

>>If I'm not, then why don't more people drive around in cars they built themselves?
Because it's goddamned expensive, takes A TON of time, and requires a huge of a variety of skills and knowledge to accomplish.
Time is money, and no self-made or kit-bashed car is going to be as economical as simply buying a $5,000 used car.

http://www.youtube.com/watch?v=FQ_QSdTND6M&feature=related

>>269600
>..then why don't more people drive around in cars they built themselves?
Because the vast majority of people are dumber than a box of rocks and can't even assemble Ikea furniture by themselves without fucking it up somehow. They can't operate a home computer without it getting completely infested with malware and virii. They can just barely figure out how to check the oil in their car and add a quart if it's low, they sure as fuck can't design and assemble an entire automobile themselves.

What's worse than this? People, on the whole, are getting *dumber*.

Actually registering it depends on state, but normally, you can register it as a "heavily modified or custom vehicle" and get plates for it that way. Unless you're machining your own engine, you can get it smog-tested with a fair degree of ease; and if you make it light enough you can register it as a motorcycle/quad bike which is a lighter class of vehicle and therefore tends to have lower insurance rates.

As for why; it's cheaper to buy a car than build one of similar quality; if truth is to be told. I ran the numbers, the cost of the parts alone is enormous; nto to mention tools and expertise.

its cheaper to buy one, than build one. The ones who have the mechanical skills, just buy a crashed, or fucked up car and fix it. You dont see this becouse i guess you live in the USA, here in Mexico there is a lot of fucked up cars, that people change motors, and drive trains, a old neon with a toyota motor, a chevrolet truck with a dodge drive train, and believe me, its not common and its not cute.

>>269600
>>So you want to build a car. How hard can it really be?
I've thought about this.

>How much work really has to go into making sure the frame is solid?
This depends on the size and weight of the car and how it is distributed... and how you want it to perform in an accident.

>Would it be worth hiring a ME with simulation software to build a frame?
If you can afford it, definitely.

>Then lets say you do have a frame. Can't just any fiberglass body go over the top of it?
Yes, but that would probably be undesirable. Fiberglass is low weight but has poor impact resistance, which is why you'll see experimental vehicles use it in races, whereas regular cars favor metal body panels. Of course, part of it is construction time and cost - on an industrial scale, it is MUCH cheaper to stamp and spot weld a metal body panel than it is to form fiberglass. For one person... actually, fiberglass might be the way to go. Just give it plenty of support, as large hollow areas do not fair well under stress.

>>269830

>Seats can be from anything I'm sure.
No. There are regulations on them for cars. There are a hell of a lot of regulations that make it practically impossible for small auto manufacturers that do not have a factory to build a car.

HOWEVER A fellow I met is sidestepping this by building a 3 wheeled vehicle that is some sort of almost motorcycle, or something. That allows one to skip a lot of shit, for some reason.

>Am I wrong? If I'm not, then why don't more people drive around in cars they built themselves?
Building furniture is much safer, cheaper, and easier than building a car, and most people wouldn't even consider trying. People do drive homebuilt cars, though - the hot rod scene sometimes will take the chassis of an old car (so it has a VIN, old to avoid emissions regulations), and build or rebuild everything, but use the strictly regulated parts from other cars (brake systems, seatbelts, airbags, whatever needs to be installed by a licensed worker). Then, they go and register it.

>>269600
>Am I wrong? If I'm not, then why don't more people drive around in cars they built themselves?
Firstly,,,, it depends on what country you are in.

In the US, the rules about customized or self-manufactured cars is that you must meet all the safety and emissions standards in effect for the year that the vehicle was built.

This is the reason that so many hot-rods use cars from the 1960's and before--because back then there was no emissions standards (so you can use as big an engine as you want). If you go further back to the Ford-Model-T cars, they don't need MOST of the safety stuff,,,, such as bumpers, safety glass, engine emissions, seatbelts, turn signals, front&rear light placement (they don't even need to have lights AT ALL if they are daytime-use-only cars--because cars back then were allowed to do that) and so on.

If you built a car right now, then you would need to meet all the standards for cars made in 2012--engine emissions, laminated or tempered glass all-around, airbags, front/rear/side collisions, rollover testing,,,,, you begin to see the problem here? All of this stuff is not economical for a single person to do. So they just get an old car and use that--and then they only need to meet the requirements that were in effect for the model year of the car they are using.

OP, try looking at Open Source Ecology. I think they have a homemade buggy for riding around an acreage.

>>269616
If you use DC motor with separate terminals for rotor and stator, you get easy reversing, and even regenerative braking. Sepex it is called(separately excited).
And you could easily make a controller for it. Just some GTO thyristors(turning off regular thyristors is kinda difficult) or IGBT transistors, microcontroller to give the PWM signal and you're good to go.

Related:
http://www.youtube.com/watch?v=7qEG9EnHnw0

Op look into FSAE and various designs. they won't be road worthy, but if you wanna design and build a car.