72v motor in a 60v system? Keyway VS. Spline?
 

I *attempted* to replace my controller a few weeks back. It didn't go well. My goal was to lift the speed limit imposed on my current controller, which is an unbranded, undocumented Chinese made 'thing'.

Now I am looking at replacing the motor and controller together, but without having to start over with the rest of the system. My vehicle is presently a 60V system (yes, you read that right, it's a five battery setup). I was looking at "Golden Motors" and they had some reasonably priced 48v and 72v motors. The salesperson was pushing me to buy a 48v but when I reminded her that it's 60v, then she switched me to 72v. But she had no technical knowledge and basically told me "it's your problem to make it work". Fair enough?

But what would the result be of running a motor built for 72v at 60v? Would the controller be able to make sense of that setup? I want to pair this is a powerful motor to help get me up and down hills a little easier (and across flat land faster). I presently have a 2.8Kw and I would like to step up to a 5Kw or a 7.5Kw.

Another question - my present motor attaches directly to the drive train with a 19-spline connection. All of the motors that I have looked at beyond 3Kw use a keyway instead of a spline. I suppose this is because with a higher torque motor, you would want the drive to be chain driven instead of "direct drive"? I am guessing that I would not want to attach an adapter?

For that matter, I could buy an all new axle/motor assembly and bolt it on. The current axle is attached to the frame with large "u" bolts. But the goal here is to get some more torque and speed without breaking the bank.

Any comments or even *opinions* would be appreciated!!

Re: 72v motor in a 60v system? Keyway VS. Spline?
 

A 48v torque motor would work perfect in a 60v cart. I'd Call D&D.

Re: 72v motor in a 60v system? Keyway VS. Spline?
 

^^ This.

More info on the cart please, Ray. Going faster with more torque can likely be done the most cost effectively without changing the rear end. ie: using a splined motor vs reinventing the wheel/drive system. The drag racers have proven that these rear ends are amazingly tough.

Re: 72v motor in a 60v system? Keyway VS. Spline?
 

I'm curious to the make of the cart as well. Sounds like a Dana 19 spline so an ezgo motor should fit.
An Alltrax 72v 500 amp controller and 48v torque motor would most likely be a perfect setup. You're looking at about $1k and you'll have great torque and top end.

Re: 72v motor in a 60v system? Keyway VS. Spline?
 

Hi all, thanks for the feedback.

The cart is a "Massimo Jonway MSE-220". Nobody is really sure what that means exactly. It is branded as a Zap Urbee, but Zap never officially imported these vehicles to the USA. It *looks like* a Mullen Motors 100e or an Atomic Electric "Super Sport". But in talking with those guys and looking over the specs, these are all different vehicles.

What I have is either a test vehicle, or a knock-off. At any rate, I believe there were a very small number of them imported to the USA and sold off at auctions.

I have put a blog together to share some videos, pictures, and some fun stories: http://zapurbee.blogspot.com/

I was not familiar with D&D but I received a marketing blast email from them last week. I sent their engineers some pictures of my setup, but he seemed to think I have an AC motor. I need to get back in touch with them. But I am positive it's a DC (no pun intended) because I have positive and negative poles, but also because the specifications say so.

So, a splined 48v motor and an Alltrax 500w? $1k is about the budget that I had expected for this job.

Re: 72v motor in a 60v system? Keyway VS. Spline?
 

Not knowing anything about the cart you would want to verify a few things.
1.Is your rearend input shaft he same size as an ezgo's and does motor bolt up the same? i would pull the motor and take it to a local cart shop for comparison of you could take some pictures and measurements of the motor shaft and I'm sure we could help you on that. If it's not the same shaft then you could always find a used rearend from a cart shop.
2. What type of throttle input does your cart provide to controller?
Hopefully it's not some off the wall signal, an alltrax will work with common inputs. If you had to you could install a pb6.

3.If you have an AC system you would be downgrading if you went to a DC setup but like you, I doubt it, unless it's a very cheap and weak system you would have outstanding performance. If it's an AC you should have three large power cables going to motor terminals then probably some smaller wires for controls.

All that being said, yes, if an ezgo motor will bolt up to your rear end or you can get a used one and your throttle input works you would love the performance of a 500 amp controller with a 48v torque motor @60v. Your controller will need to be rated for 72v also so for your budget the 72v 450-500amp will probably be your best choice.

Re: 72v motor in a 60v system? Keyway VS. Spline?
 

Take some pics of your motor, controller and any other electronics you see, that would help a lot.

Re: 72v motor in a 60v system? Keyway VS. Spline?
 

Just checked out the blog. The fact that you have motor braking means cart either has an AC or Sepex system. The performance you stated going up a hill says it most likely a separately excited DC motor. That changed things a little bit but as long as you are comfortable with wiring and mechanical work what you want can be accomplished.

You're in for some work and a little more than your budget most likely to build a sepex system, especially at your voltage. I would now recommend a Curtis 1244-64xx controller, 400 amps is more than enough for your car. Call D&D and talk to Vic and tell him what you have. He can build a motor for your setup to paid with that controller that you will love. Your budget just increased by at least 1.5% though..

Re: 72v motor in a 60v system? Keyway VS. Spline?
 

I was Googling around trying to find info on running a 48v controller and motor with 60v and I drove myself back to this post. I completely forgot I had asked this question here!

I am down to the wire and I am ready to buy my kit. But I have to make the choice of 48v or 72v. And I am getting conflicting information from the community (I have asked around on DIYelectriccar and the GoldenMotor forums, and here!!).

Some say that so long as the controller is rated for the volts I supply, I should be fine. According to the specs on the Golden Motor VEC 300 controller, the 48v controller will accept up to 96v. Check!

The question seems to be - can I have the controller feed 48v to the motor? This seems to be where I run into controversy. And the question is does the controller switch power or does it regulate the power?.

I can't imagine that the controller regulates power. Stepping 60v DC down to 48V DC at 300 amps would require one hell of a transformer. Then again, we are looking at the *flow* at this point. If my motor is not drawing a flow out of bounds with the controller, this wouldn't be a problem, correct?

I have also been told I should buy a 72v rated controller and motor for my 60v system. But with the little I know about power, I would think that this would result in lower RPM's and lost speed. And since speed was my main objective here ...

I am curious to see what you hackers have to say about it. All I can find on this subject is e-Bike enthusiasts who are working with 36v and 48v packs and motors. Not very helpful.

Re: 72v motor in a 60v system? Keyway VS. Spline?
 

Well I can tell you that a Alltrax adjustable 450 amp controller for 72 volts will run on the reverse half speed setting of 36 volts but it's slow as crap and has no torque at all.

When I built my last 72 volt cart my son was in his senior year of high school. For his school project we made the cart into his paintball tank and ran it in half speed reverse per Alltrax phone call. It was a dog it would barely turn the motor.
here is a link on it for you.:shock:


http://www.buggiesgonewild.com/membe...-e-z-go-9.html