Ok guys... after finding this site I would like to see if maybe I could get some help on a project. I see many of you have converted the riding mowers to electric and could probably give me some insight.
I am wanting to convert a craftsman tractor with hydostatic drive to electric... but not to cut grass to use an electric train for kids to ride on. I already have a great design using a craftsman tractor but would like an electric one to use inside malls during the cold months.
From what I have read I should use a 24v forklift motor with a controller. I was just wondering the run times I would get using 4 or more batteries... and also how to "connect" the motor to the drive train since some have done it.
My thought is using the belt system already there and attach the motor using the same pulley from the gas engine if possible.....
Any help would be appreciated!
An indoor electric partytrain, a very nice idea for kiddy rides in a mall.
Here are some thoughts. Sorry about the length.
I think a hydrostatic is going to be difficult to drive because you will have two different power controls. You will need to add motor power then add load with the hydro then add motor power then more load. With a ICE the governor does this for you. You set the throttle to an RPM and the governor controls the throttle. A manual trans or direct drive may be a better choice.
With a hydro you will need to make sure you never have the electric motor under high power when you put the hydro lever into neutral or the motor will run away and maybe blow up.
If you go with a belt drive manual you can dispense with clutch and such. Once you get the primary reduction into the trans right you will find that the torque of the motor will be sufficient.
Remember when selecting gearing that electrics make the most power at low rpm up to about midway into there RPM range where ICE the power is more to the higher end of their range.
I would select a motor with power specifications similar to the D&D ES-15A for what you want. I can pull a 5 to 6 ton load on a skid plate at about 5 mph with 48 volts and 350 amps with my pulling tractor with a similar motor. There are a good selection of purpose built motors as well as a number of Lift Truck (Hi-Lo) motors out there.
Please look at the conversion I did shown earlier in the thread. I used a 6.7 inch, 24 - 36 volt motor on 48 volts and it works very well. I stress the Cub Cadet because it is built to last and will take more load then any garden tractor out there. As a note, 95% of the sucessful pulling garden tractors are built on Cub Cadet Transaxles, no matter what Sheet Metal they have on them. Also since the tractor is a shaft drive conversion is a snap. Another nice thing is the wheel bolt pattern is the same as 5 on 41/2 same as Ford and Chrysler passenger cars.
On brakes, NO garden tractor has brakes sufficient to stop a load like you are maybe thinking about and remember an electric motor has NO engine brakeing. The best you can do is get the mechanical disc brakes discs available on some of the hydro tractors and put a good hudraulic caliper and master cylinder on them. Maybe electric trailer brakes on some of the towed wagons? You sure don't want to run one of those poor kiddies down.
Batteries, you will want BIG deep cycle batteries for a day of running around the malls. The nice thing about the train idea is you can put batteries into the towed carts.
Your train idea has me thinking about next years town parade. I can get a few of those BIG FOOT yard wagons from Harbor Freight and build farm wagon flat beds on them and make a miniture hay ride to pull with my Cub Cadet puller.
So you will need basically the same things as a car conversion . . . PLUS EXTRAS.
- A good motor, for this application some rated at 6 - 10 HP continious, RPM range around 3600, you should run at 48 volts (that is the highest "SAFE" voltage accepted by insurance underwriters) <bet you forgot about insurance>. No lower then 36 volts for efficiency.
- Look at external cooling for the motor or be sure the motor is rated for the loads and RPM you are looking at.
- What ever you need to connect the choice of motor to the choice of tractor transaxle
- A good controller with a sufficient heat sink to not go into overtemp shutdown/cutback (big loads create heat).
- Zero to 5k ohm Pot box or some other throttle device.
- At least 1 good high amprage contactor (two are better-safer) with pre charge for the controller
- Suffient fusing
- Safety interlocks everywhere. Best is a wrist strap so no one can just jump on and go.
- Mechanical disconnects fot the motor contactor in case you train comes unhooked.
- Lots Of Batteries, without knowing the total weight, speed and other factors it will be hard to estimate what kind of watt hours you will need.
- Depending on your frequency of use suffecient battery charge capacity. (Unsupervised battery chargers are expensive)
I know I've forgotten things so others please chime in