Stripping Down pt. 4 - Painting the Chassis

A whole bunch of cutting and grinding gets rid of the old motor and bearing mounts.

Then it's a matter of lifting the whole lot...

And flipping and painting the underside. I've added some 50mm angle iron to reinforce the area where the 240kg of batteries will sit.

Stripping Down pt. 3 - The Lifting Ram

I wasn't sure how to get the main lift ram out of the chassis - it's pretty heavy and in an awkward position. In the end a set of forks made the task pretty darn simple.

Stripping Down pt. 2 - The Main Gearbox

After removing many, many bolts, the main gearbox that generates the counter-rotating shafts is removed.

Stripping the chassis

The aim is to get rid of all the internal combustion related bits, so first, off with the engine.

There's oil and grease everywhere - once converted the machine will be much cleaner...





You can see in the above shot that the machine has a thick steel plate beneath it, which is basically dead weight for machine stability. Seeing as the batteries will weigh 240kg, there won't be much use for it.

Off she comes.

And onto the scales - 157kg.

Anatomy of a wheel gearbox.

The machine really hasn't been maintained as well as it might have over the last 36 years - pretty much everything leaks, including the oil seals on the gearbox. While I was pulling it to bits I thought I'd grab a shot of the internals.

Not really the most complex of gearboxes...

Wiring up the hydraulics

The neighbours who have so kindly donated the machine to me to convert also happened to have a collection of 12v deep-cycle batteries out of a telephone exchange which they offered as well. At 150 amp hours capacity, they'd be ideal for this machine. The only catch is that they're huge, and very heavy. This is the hydraulic pack wired up on the bench with the batteries next to it:

To start with I connected one 12v battery using 4 AWG cable and a 100A circuit breaker.

The wiring was a little tricky as while the motor was being supplied with 12v, the solenoid valves on the pack need 24v, so I used a pair of small gel-cells to supply the 24v - you can see them tucked in between the pack and the big batteries in the first pic.

With a bit of hose hooked up to the output and a lot of spilled oil, the thing works.

Next job was to remove the old engine-driven hydraulic unit:.

And fit the new unit along with batteries:

The little grey box with a switch is my control for lift or drop. The 12v supply worked well, but not as fast as I'd like, so I installed the second battery and adjusted the wiring:

It'll get some cable ties added to keep everything in place, despite this battery location being an interim measure - ultimately they'll be located where the engine is now, but I want to keep the machine as operational
as possible during the conversion. The downside with this location is the weight of the battery - I mentioned they were heavy: 60kg each, so that's 120kg sitting on the front.

The video below shows the hydraulic lift in action, with the difference between 12v and 24v:

The Hydraulic Power Pack

A bit of snuffling around on Ebay finally turned up what is hopefully a suitable replacement for the engine-driven hydraulic pump:

In a previous life it was in a stock-picker, a kind of forklift where the operator rides up in the air with the forks.

Popping it open reveals the gear pump and a fairly modest amount of filtering on the suction:

Which hopefully should be sufficient as it'll be permanently hooked up to the main ram, so not much scope for crap to get introduced. I don't know terribly much about hydraulics, so to be sure I wasn't going to hurt it, instead of using the normal general-purpose agricultural hydraulic fluid that I'd normally dump into a tractor, I went and got it some Caltex Rando HD 46, which is pretty much a straight mineral oil.

The unit came with this block of solenoids - it's set up to supply two "single-acting" circuits. I'll only be using the top one, which appears to have a bigger hole, and the black one at the bottom that allows the oil to drain back into the tank when the platform is dropping.

At the top of the block there's some kind of pressure sensor, which I'd love to do something clever with, but it has 3 wires coming out the top and no indication of how it should be wired, so I doubt I'll be able to work out how to use it.

It's a 24v motor rated at 2.2kW - next thing is to get some batteries, hook this bad boy up and start moving some oil.