[amesmich]

1) Looks like those are 6 volt batteries. Please confirm. You say a 72V system. Let's see a voltmeter reading on the battery set.

The batteries are 12v and the pack is fully charged. Aprox 88-89 volts off the pack.


2) Motor nameplate is 36 volt. Why are you using a 36V motor with a 72V system.

Because I wanted tire smoking torque. The windings in the motor are thick so I figured I would over volt it for even more power.


3) You say it is a SepEx. How do you know the motor is a SepEx wound motor?

By taking the motor apart and looking at the windings. In addition to its 4 posts A1, A2, F1, F2


4) What is the specification of the controller?

It is a SepEx. Page 11 of this document is the wiring diagram. http://www.kellycontroller.com/mot/downloads/KellyKDUserManual.pdf


5) I cannot see due to the chain guard, but it appears to be an overdrive. All carts, bikes and other such EVs have a much larger sprocket on the wheel than on the motor shaft. To the tune of 4 to 1. If you in fact have a larger sprocket on the motor than the wheel, it would explain the very low wheel torque. Remove the chain guard and let's see what you have.

I purposly ran a ratio of close to 1:1. Its about 1: 1.2 so yes I know I will need a lot of torque but I figues with the size of th emotor and the 72v pack I would have enough.


6) How were the parameters set for the controller to match the motor characteristics?

I dont know, maybe this is my weakness.

7) Please show a complete wiring diagram.

Page 11 here http://www.kellycontroller.com/mot/downloads/KellyKDUserManual.pdf

 

[amesmich]

Thanks Major.

I am thinking I overestimated the power of the motor. I may have to reduce that gearing. I can do that by mounting my axel on the bottom instead of the top. I had this in mind from the start.

I also think I need to learn more about the feild characteristics. I cant measure the resistance because I dont have a mili ohm meter. The resistance is dam near zero which it should be. What the reactance is, I dont know, and i dont know the current rating of the field. Live and learn.

 

[amesmich]

I just measured it. its 1.1 ohms and that included about 24" of #8 copper lead. It may be exactly one with out the wires comming off the motor. I was too lazy to access the motor to detach one so I measured at the controller with one taken off. I have this wavetek meter and it has a calibration cert (out of date) so its pretty accurate. I think I am going to go ahead and change my gearing to a 6:1

 

[amesmich]

Hey Major,


I looks at my gearing and my current setup I have a 17 tooth sprocket driving a 20 tooth, so almost one but not quite, a ratio of .850.

The smallest drive sprocket I can get is an 11 tooth, and the largest driven sprocket I can fit/ get is a 40 tooth. I am going to make this switch which will give me a ration of .275

You recomended a 1/6 or a .167.

Ill try this an get a new controlelr. If this does not work I am screwed.

Thanks.