A Different Take On Electric Motor Cars

[Craig Carmichael] has been hard at work on his electric hub motor for cars. Unlike typical electrical vehicles the plan is to bypass the transmission, differential, and everything else all together by connecting directly to the hub of the wheel. The goal of giving greater thrust and still allowing the use of a gas engine if need be.

There’s really too much detail for us to even begin to try to explain the entire project in a short recap, but [Craig] builds the entire motor (from magnets to coil windings) and wires his own controller (from schematic to finished PCB), all while documenting the process thoroughly for those wishing to make their own.

43 thoughts on “A Different Take On Electric Motor Cars

  1. @Jerome The bracket scheme is the easiest way to do this (that I’ve seen) on a conventional car. If you got rid of the brackets and replaced them with hub motors you’d have to trash everything from bearings on up.

  2. The best part is, if you paint those brackets International Orange, no one will try to steal your car, because they’ll think it’s already had a wheel “booted” by the city. :)

  3. This might be good for mass transit, shipping, and other non consumer cars but the massive increase in unsprung weight at the corners will be a huge hurdle for any car to handle in a manner that consumers have come to expect.

  4. I was just thinking about how to do this to my car the other day. I have a fwd car so in theory if I used this method I could effectively have a hybrid 4wd/awd……Im heading over to the site right now.

  5. I love this idea, but reading his site, it says that they still need gearing down to work well. This led me to thinking about how I could do this on my VW Bug electric car project in the planning phases, and, you could mount this motor on the side panel of your car, and run a motorcycle chain down to the wheel, through a slot in your wheel well, to gear it down. This way, you could even use a larger diameter rotor and stator.

    The thing is, gearing it down just cuts down the higher speeds available from a true hub motor.

  6. I’m concerned about this. Something he doesn’t mention is that cars, specifically the transmissions of cars, aren’t built to be put into neutral and pushed around. Every rear wheel drive car I’ve had has stated in the manual that if you are planning on towing it more than 50 kilometers you have to either get the drive wheels off the ground or remove the propeller shaft to prevent damage to the transmission. The same goes for the FWD cars, lift the wheels before towing or just don’t do it at all. It sounds to me like he’s just planning on putting the car in neutral which will work for a while… but will eventually kill the transmission.

  7. I’m sorry, but this is a horrible idea. For the amount of work he’s putting in to this, he might as well put the motor just outboard of the transmission or something. This is not something you would ever want to do to a modern car (with ABS, traction control, etc) and many cars will be damaged by higher speed (say 45mph+) travel without the engine (and hence, hydraulic pump in the transmission) running.

    This is not practical because it increases the overall width of the car, and you must be constantly conscious of this idiotic lump on your drive wheels, lest you bump a concrete barrier or curb and ruin it.

    This guy gets a B+ for his efforts, but these efforts are incredibly misdirected. He needs to scrap this entire project and start over. It’s actually kind of sad to see someone of his age (and experience, I would assume) pushing forward with such a stupid idea!!!

  8. Good God, I just looked at the rest of his website and I just can’t get over how stupid this idea is. Is this guy still working on this, or has this project stalled indefinitely? I’d be surprised if he goes any further with it. His idea requires the fastening of his bizarre hardware to the knuckle, behind the wheel. On many cars, the knuckle is cast aluminum, and any drilling/tapping of this piece can cause serious safety concerns!!!

  9. His custom-wound motor is a design to behold in Kindergarten. Beyond that it’s a way to make soot necessary in a postapocalyptic Mad-Max world driven by roving gangs of electric utility…people; it’s inefficient in every way but that of selecting rotary drive rather than requiring coils in the pine loam. I hope he permits himself another tool (not bolts and nuts) and a few design iterations.

  10. this is an excellent idea, built up to prototype. it is the most likely way to adapt/improve existing vehicles, and i think sets good basis for developing hub based internal motors for future pure electric cars with variable motors in all four wheels, keeping (what was) engine compartment space available for batteries (until they get smaller and lighter)

  11. I have to think the first problem with ANY retro fit hub motor, would be the extra unsprung weight with a suspension not design for it In the event the mounting flange on this axle is strong enough to hand braking forces it’s probably strong enough to handle propulsion forces. This looks to be a front wheel drive car, who’s rear suspension was not design for a drive axle.

  12. This project is wrong on almost every level possibly excepting the goal of building a plug-in hybrid. That motor has got to be hugely inefficient and it looks like it’s only burning up a mere kilowatt of power. He’s not going anywhere very far or very fast.

    There are a few folk working on converting car and truck alternators to motors using electronic commutation. The results in terms of power output for the given size and weight can be impressive but it’s definitely not trivial to get good efficiency.

  13. This is so horrible it has flipped the dial to awesome. Those of us who are electric drive professionals have had a huge laugh at this fellas expense. Not only is the engineering horrible, but the website is horrible and the packaging is horrible .. in fact with the combination that this guy is serious makes it so horrible that its comedy gold.

    In Wheel Motors when properly done are a solution for distributed tractive effort, however the added expense of the inverters for each wheel make it a cost-prohibitive solution, this is the same problem for any multi-axel electric drive. Of course there is added functionality when you can individually control each wheel, but you have to program that functionality and coordinate it with the rest of the high level vehicle controls (ABS etc).

    Also PML Flightlink or as it now is called, Protean Electric has changed its name 3 times in 3 years and has no product still, they are vaporware peddlers, along with most other people who are “developing” in Wheel motors, they pay themselves salaries from their investment money and then never deliver any products or customers, watch out folks in the green game.

    There are at least 20 “companies” out there claiming to have products, but so far none of them except for one GM prototype 5 years ago, have actually functioned properly and without damaging itself in a commercial passenger vehicle.

  14. @Phil, Nate



    Agreed. I feel sorry for this guy, but at the same time, this is pretty entertaining. It reminds me of those guys who claim that a little electrolysis going on inside a 12″ section of PVC pipe will get you 100 miles per gallon, LOL.

    Bad idea, and clearly little or no understanding of the word “practical”…

  15. Wow, rough crowd. How many of you have built a project to this level, at home, purely out of a love of engineering. It may not be the best solution, it may not ever really work (I have my doubts), but kudos to him for actually building something. It’s certainly within the hacker mentality. Cut the guy a break. I found it an interesting skim read.

  16. Yeah, when did the hacking community get filled with so many naysayers. There have been like 4 attempts at designing a diy wheel motor on the electric car forums. None of them could even settle on what type of motor to make much less actually produce a prototype. If no one ever makes a bad diy motor that we can learn from then how are we going to make a better one. But maybe these guys are right, maybe we should all just wait around for professional engineers to make all this stuff for us, and hackers can just stick to driving LEDs with an arduino.

  17. This is exactly the right approach to get things started, thanks for posting it! Hubs are where it’s at for retrofit. You’ll eventually be able to electrify your car incrementally, one hub at a time, and the electrical/mechanical stuff will be contained inside the hub. It doesn’t have to be heavy. Nice work.

  18. Hi,

    Many thanks to Hackaday and to those with positive comments. Note the URL, wherever the site may be hosted in the future is http://www.ElectricHubcap.com .

    Most of the negative concerns expressed have been dealt with at least to an extent since, as development proceeds.

    * For those who want more than just the plans on the website to go on, I plan to offer self-paced Electric Hubcap motor system building workshops this fall – details on the web site.

    * The 2008 motor shown was connected directly to the car wheel. That proved impractical, notwithstanding that the car moved.

    * A mechanical torque torque converter is now in advanced stages of initial development to optimally couple the motor to the wheel. Replacing gears with the torque machine, invented in 1923 but never adopted by the auto industry, could have saved the world around 1/2 of all the fuel used for transportation from the 1920’s to now. It’s so effective and efficient that the 4.6 KW axial flux 3-phase brushless supermagnet motor, which performs well, should be sufficient to effectively run a car. With its unfamiliar concepts and principles of operation and little previous development for guidance, it’s taken longer to arrive at a simple, practical design than developing the motor itself. (Details soon – I didn’t choose the moment for this article to appear.)

    * The motor system has somewhat springy supports, and is now coupled to the wheel by tapered pins; the next outer housing is to be bowl shaped. All this allows the motor some slack to pivot up and down relative to the wheel, so as not to seriously affect vehicle handling on road bumps.

    * The depth of the system can probably be pared down to about 4 inches. It won’t stick out past the rear view mirror. True, care will need to be exercised for parallel parking unless the motor is on the outside wheel. Driving the wheel itself makes substantially better use of motor, batteries and the power grid to charge them. Plus, I’ve found no other practical place to add a motor to an existing car.

    * The motor now has two plugs/sockets and four bolts to install or remove. True it will take a few extra minutes to change a tire, but no special expertise.

    Craig Carmichael

  19. Craig,

    How are you going to deal with the inability of the retrofitted cars’ transmissions to stand up to ‘freewheeling’ while driving around under electric power? The hydraulic pump is driven by a skinny shaft that originates at the torque convertor in automatics, which means that without the engine running, you will destroy the bushings and bearings very quickly. Many manual transmissions require that the drivetrain be uncoupled from the drive wheels before you wheel it around without engine power.

    What about this “Torque Machine” – You don’t think that companies are constantly exploring new ways to make their cars more efficient? Your claim that going that direction would have saved “1/2 of all fuel used from 1920’s to now” is BEYOND idiotic, especially with ZERO supporting data on your part. Seriously, man. Do you know how bad it makes you look when you say something like that?

    No offense, but the way you are going about doing this suggests a profound lack of understanding of the fundamental concepts behind the way that the world of engineering operates. I looked at your site, you make various wild claims about money that *could* be saved and things that *could* be built, and seem very enthusiastic about it, but have zero supporting data.

    This product is clearly aimed at older vehicles that are what you would call “inneficient”. So, you want to bolt this bulky motor on the *outside* of the wheel. What happens when you get a flat? Without a tire that will NEVER go flat, your product is useless to a vast majority of the people out there. Have you built any of these “ultra-efficient plug-in hybrids” that you speak of on your website?

    Your wave generator project is stalled. I see why. You have some wild claims there, it seems that you are claiming “Vancouver Island Floating Wave Power: 900 MW, 3 billion dollars, environmentally benign, can be done a bit at a time”. Do you have any data to support this claim, besides your clunky little setup that sits on the beach?

    You are clearly very eager to do something. I suggest that you focus on one thing, and try to make it happen without all of the crazy claims during the development process. You’re only going to dissapoint yourself (and maybe others) when the product ultimately fails to be what you claim. You’ll learn a lot in the process (hopefully about how engineering really works), and *maybe* someday you’ll come up with something that actually has financial benefits.

  20. Jake- Presidents claim they’ll reduce unemployment, swear they’ll uphold the constitution and cut the budget while thy’re at it, none of which they do. Yet we elect them over and over. Yet here’s a guy who’s actually DONE something, made something work, and you’re hammering him because it’s not ‘engineered’?

    Engineering is merely the application of known attributes toward a specific problem. Research is about discovering those yet unknown attributes.

    I’ll take one Craig over 10 engineers and 1000 presidential candidates. We’ve got the world’s best engineers, yet we’re still facing monumental problems with no apparent solutions. It’s guys like Craig that are going to come up with those solutions. Then they can be ‘engineered’ to the max.

    I’ll put my money on Craig and guys like him.

  21. In October I made an “Electric Hubcap” (“EH”) Outboard out of one of the prototype motors and my old Honda 7.5 outboard. I’ve put four videos up on http://www.youtube.com (search “Electric Hubcap Outboard” or “Turquoise Energy”).

    The EH should be about the most efficient of all motors and I hope to test the outboard soon against an induction motor electric outboard, both on the same boat using the same watts from the batteries, to see how much faster it travels the same route. (Hopefully that’ll be in the next monthly newsletter.)

    I’ve also been improving the design and construction of the motors and will be offering parts to help people build their own motors. A student has just completed his own EH motor – the best one yet! He plans to put it on a motorcycle.


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