EcoRider: New Motor and Pulleys

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by Tim Fulton on September 30, 2010

This entry is part 13 of 15 in the series Ecorider

Last I wrote, the EcoRider’s motor had given up the ghost. The power requirements were just too much for the motor to handle and it overheated. I contacted some of the local EV guys for suggestions on replacement motors and if they had any suggestions on where I could get the motor rewound. One of my friends there highly recommended going with a motor with a higher power rating, the Mars ME0708. I was quite reluctant to go ahead with this motor due to the price tag of $450 (plus shipping on a 30 pound motor). However, I did happen to take a look on ebay and find someone selling one and the price was much more reasonable, so I nabbed it.

The same friend that recommended the motor also works at Helwig Carbon a spring and brush manufacturer. He works in the test lab and had actually tested the ME0708. They had developed new springs for the motor that extend the brush life by roughly two times. He was nice enough to get me the springs he had used to do the testing.

ecorider

One great thing about this motor is that I have specifications on it. That means I know almost the exact rpm it will be turning while cutting the grass. This allowed me to very accurately size the pulleys needed for the mower this time around.

ecorider

However, there is a small problem with this motor. The shaft is significantly shorter than the Baldor motor I had been using before. As you can see in the picture, the second pulley isn’t fully engaged on the shaft. Some modification to the pulleys will be needed to get that second pulley on more.

{ 3 comments }

1 hondo434 October 31, 2010 at 9:48 am

SVOboy,good work on electric mower! I have a suggestion/question. I have been working with capacitors in homes and my car. Placing a capacitor between the + and — posts has lessened the load on the altinator in my car. The engine is quieter because it doesn’t have to produce as much amperage. The capacitor stores the reactive energy needed by the motor and saves it until the motor needs it again, thus increasing efficency up to 30%.
If you consider this experiment I would suggest getting help in sizing capacitor and installation method.
New appliances are increasing efficency by adding capacitors with ratings about 95%.

2 Tim Fulton October 31, 2010 at 8:50 pm

Hello hondo434. I (Daox on the forum) am the maker of the mower. I’m not sure how a capacitor can lessen the load on the alternator to begin with. I can see it smoothing the power draw out a bit, but not lessening the load. Same goes for the mower, except the mower really doesn’t have any spike loading except for take off and engaging/disengaging the blades. Can you explain in more detail why you think a capacitor would be of use?

3 hondo434 November 1, 2010 at 7:45 am

Tim, I’m thinking if there is a higher efficiency to be had that it would be in allowing you to have a slightly smaller battery pack, but letting you have similar power. I am just brainstorming and maybe if you know a electrical engineer who could comment on the idea.

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