It's been over a year since I posted here about my plan to electrify a model G for use on a small farm.  I was able to drive it for the first time last Friday.  I work for Zero Motorcycles so I have access to parts at no or low cost, which made things a lot easier.

I went with a 75-7 motor, which can produce way too much power, 68hp and 97ft lb of torque, so I used the motor controller to tune down the max RPM to 1800 instead of 6000 and the acceleration to more closely match an old gas engine.  I may also turn down the rate of torque application to prevent jerking and lighten the load on the old transmission.  That's all powered by a Zero lithium battery.  Because of the available motor torque, I did not need any kind of reduction, the motor goes right to the input shaft via a Paraflex coupling.  There is no clutch and no need to shift gears so you only change gears when stopped.

Still to do, is to connect the clutch pedal and brakes to the motor controller.  I plan to use the clutch as an input to decrease motor power.  For instance, 1/2 way on the clutch and you'll get half of what the throttle is set to, all the way in and the motor stops.  The brakes will be set up so that each brake can work by itself normally, and the motor will stop and go into regen if you use both.  That way you can still use them to turn, but won't fight the motor if you want to stop.

It's been a fun project and everyone on the farm is eager to use it for weeding and after I make a bed shaper for it, forming strawberry beds by machine instead of with shovels and hard work.

Now for the questions.  The brakes don't seem to be very effective.  No bad grinding noises and they do stop the machine, but I'm not getting a whole lot of braking for my effort.  Is that normal or should I open the thing up and take a look?

If I just want to look at the condition of the brake shoes, can I pull the axle housing with the axle and drum on it and put it back in one piece without removing the axle from the housing?  If I do have to take it apart and replace or turn the drum, the shop manual talks about always using a new clamp ring when putting it back together.  Are those available?

Thanks for any advice.

What is the footprint and weight of the batteries you plan on using?

Thank you for sharing your knowledge about the tractor.  I'll post some photos this weekend if I can figure out how to do it.  I couldn't get it to work when I first tried.

The battery is a 7.2kW battery from a Zero motorcycle.  It is about 10x15x10 inches and weighs about 80 pounds.  It provides about 100Vdc to a Sevcon motor controller.  The motor is a permanent magnet 3 phase AC motor built by Zero.  I got a full battery/wiring harness/charger/controller from a decommissioned bike.  My motor was new, but had a scratch on the paint so couldn't be sold.