Electric Tractor Project - Plan B

 

 

Donor Tractor for eTractor Project

 

Managed to find a suitable David Brown 880 Selectamatic tractor for the project (yep, that's her above). Has been sitting in a paddock for quite some time, but the chap said it was a runner. Reasonable price and he delivered it for me, so she'll do just fine.

First step: Let's see if we can get it running and then I can check the hydraulics, PTO, brakes, clutch, gearbox, etc. After getting the starter motor to work (tapping the solenoid with a hammer to make it engage) the motor started slowly turning over, speed building, turning over faster and, yes, it started (queue bunches of smoke out the exhaust) - bit of rough running, but then settled into a healthy rhythm.

Quick let's test everything in case it dies. Clutch and gears = good, brakes = left ok but right brake not working, hydraulics = bit sluggish but seem to have ok lifting power, diff lock = bit sticky but ok, and PTO = good. Right let's drive her in the shed and shut her down. Damn! Steering stops working part way in (steering wheel just spinning freely and nothing happening). Hand turning the front wheels, we're in, parked and I shut the old girl down (but sad that that's the last time that engine will be running).

 

 

Next step: Time to strip away all that ICE stuff. Drained all the fluids first. Then air cleaner, radiator, fuel pump & filters, injector pump, water pump, etc are gone. Removed the head, as the next step was to remove the pistons before removing the block and crankshaft. But wait!

On investigating how to remove the engine block I've now realised that my Plan A to attach the electric motor via gearing to the flywheel (thus keeping the use of the double clutch for running transmission and PTO off the one motor) is flawed.

The weight of the flywheel, currently supported by the ICE's crankshaft, would be too complex to support and then keeping it balanced and not putting strain on the gear shaft (that I'd have to fabricate) and bearings supporting it. And the crankshaft can't be re-used, as it attaches to the block and not the sump frame and will need the oil pump running for bearing lube (essentially keeping most of the ICE components, which doesn't gel with me). Hmmm...

 

 
So, Plan B is to now do away with the flywheel and clutch and instead use two electric motors & controllers - one attached via gearing to the PTO shaft (the smaller shaft within the outer transmission shaft in the above photo) and the second motor attached to the outer transmission shaft (the outer splined shaft in the photo). Actually, I think this will be a lot more efficient too - don't need to run the PTO motor unless the PTO and/or rear hydraulics are needed. Could also use different gearing to suit each one too. Yes, I think this is a way better plan!

Right, next job - try and block & tackle out the great lump of an ICE (need to split the tractor and remove the engine block with crankshaft, flywheel and clutch attached) - should be fun 😃  Catch you next post with a further update.