Steven, If you decide not to use that motor I have some series wound Crown forklift motors left that I sell for $150 + shipping. They are around 3.5 Hp, 24-36 volts nominal, >50 lbs and are easy to find a controller for. They are very robust and I can vouch that they will work on 48 volts without modification. Contact me off list if you are interested. Dach.
________________________________ From: Jeff Major <[email protected]> To: Electric Vehicle Discussion List <[email protected]> Sent: Monday, March 4, 2013 5:49 AM Subject: Re: [EVDL] Suitability of a converted BLDC motor to EV go-kart Hi Steven, That is some interesting work you did on the motor. But I don't think it'd be wise to use it for a go-kart. Using your volts/RPM figures, 24V will give you about 100 RPM. So you'll end up with a 200 pound 1/2 hp motor. The controller will also be a real pain. No, motor controllers do not step up voltage. About the only place to look for one is AC forklift drives. I think Sevcon makes some. They're not cheap and not versatile. Do the kart project for the kids and to learn about EVs. But find a more suitable motor. If you can put magnets on ACIM rotor, you could put a shaft and bearing on a golf cart motor. Then you could use the controller and charger also. Regards, Jeff M ________________________________ From: Steven Fahey <[email protected]> To: [email protected] Sent: Monday, March 4, 2013 2:10 AM Subject: [EVDL] Suitability of a converted BLDC motor to EV go-kart Hi, Glad I could join up. After a bit of searching in the archives, it looks like the members here know how to match up motors with controllers. Since I started thinking about building my own go-kart - really just an off-road buggy for my son to scoot around with - I've been wondering if the left-over motors from my previous projects would be suitable. I have what you could call a BLDC (brushless DC) motor in my garage, but it comes from an unusual source: I converted it from a 7.5HP induction motor, by turning the rotor down on a lathe, and installing permanent magnets on it. I left the winding mostly unchanged, save for extending all phase wires out separately. Why? I meant it to be a 3-phase alternator for a wind turbine. In the end, I did not use this one for the wind turbine project, I did a smaller motor conversion, better suited to my needs and less heavy on the tower. For anyone who wants to see details on that project, and inside my motor conversions, look at this www dot sparweb dot ca. The motor in question is the converted Toshiba that I show on my projects webpage. I did a number of run-up tests using a lathe to determine its potential as a generator (which is good). Perhaps they are of some use in determining its suitability as an EV drive motor. Of course, if the original induction motor would have been better for an EV, the irony would not be lost on me! I did not have an EV in mind at the time. Really my only problem is having exceeded my practical limits with the size of wind turbine that I can mate up with this generator, so I'm consindering other uses. It would be most convenient if I could equip the go-kart with a set of four 6-volt golf-cart batteries, so I can tie it into my existing off-grid 24V battery bank. Since a go-kart is just for recreational use (and maybe a farm runabout if I put a toolbox on the back) I'm not too concerned about endurance. #1 goal is fun. #2 is to teach my kid some things. #3 is for all the work on that motor not to go to waste. I spent some time looking at the datasheets and installation manuals for Kelly motor controllers. Obviously they are written for installers using "off-the-shelf" motors. The wiring looks straightforward enough, but I've read in your archives that the harmonics are very important. I can't use an induction motor VSD to do this kind of thing. There are controllers specific to BLDC motors that I must use. At this time I don't have any hall sensors built into my converted motor, but it could be done, if it's needed. The original motor windings are rated for 240V/480V, but as I said, I'd rather operate it from 24 Volt batteries, so that it can recharge from wind & solar. Do these motor controllers "step-up" the DC from battery source to a higher output voltage? The converted Toshiba BLDC motor weighs about 200 pounds. I expect the battery bank will be at least another 200, one driver (no pax seat) requires another 200 pounds, and I roughly estimate the welded steel framework, driveline, and equipment to demand another 300 pounds. Roundly estimating 1000 pounds machine when complete. A differential and disk brakes will be necessary... I won't be winning any land speed records. So my questions are: Am I starting off on the wrong foot with this motor? Will a typical BLDC motor controller be able to drive this motor without burning up? Do the motor controllers require hall-sensors to work properly? If the odd features of this motor make it a bad candidate, then so be it. I'm still interested enough in making an EV go-kart, and getting my hands on old induction motors is not hard. Thanks to anyone who can help. Steven Fahey http://www.sparweb.ca/ -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130304/524756df/attachment.htm> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA) -------------- next part -------------- An HTML attachment was scrubbed... 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