Motor repair

Just found some pictures of the motor repair I attempted last week. This is the motor from my own Berlingo which blew up in 2006. I had a spare so didn't do anything with this one until now, when I had to borrow one from another vehicle for Steve.

I knew from the way it had blown up the controller that the field had shorted to the armature at some point. But where? By connecting a sensitive ohm-meter and tapping the windings with a screwdriver handle, I found the point - of course, it was in one of the places where the interpole winding runs next to a field coil. There was clearly not enough insulation between them, and it had flashed through and taken a chunk out of one of the outer conductors of the field winding.

A local armature winder (R&T Barr of Dunfermline) was kind enough to not only tell me how to repair it, but lent me the materials to do so! He didn't have time to do it himself but will be skimming the comm on the same motor.

Here's my very first motor repair then.



This is the damaged wire, dug out of the winding. Beneath it is self adhesive fibreglass tape. I've attached a piece of earth wire from a normal domestic supply cable to bridge the gap, about to solder it in place.








The connection is soldered, wrapped in yellow (Melonex?) plastic tape and then another couple of layers of fibreglass between it and the large interpole winding which is now tied back on top with the magic armature winder's knot.







I hope it works!

Meanwhile.

I almost forgot what this was supposed to be about. Yes, since you ask, I've been doing a little work on the 3 wheeler.

Here is a picture of the current state. Steering and pedals are in, the brake lines are not in place yet.




It's quite solid now and I look forward to putting the motor and belt drive in and getting it to move under its own power. The current weight is around 140kg as it is shown there. The difficult part, the bodywork, is starting to loom!

Nice EVs spotted

In Edinburgh at the weekend, we spotted a shiny new TNT delivery truck, a Smiths Electric model. It pulled up silently beside us on the street while the driver checked an address, and then moved a little further down the street - you could just hear the contactor as it started and a faint whine from the reduction gear. On the side below the box you could see the Zebra battery cases with warning stickers on them. Anyway, a picture is worth more:


Nice truck!

Ideal for city deliveries. It presumably has no problems with the steep hills in Edinburgh.

Long distance EV driving

I had a visit this week, a rather brave chap called Steve drove his Berlingo all the way from Telford to where I live in Fife, about 350 miles. He stopped at campsites and friends houses to charge up.

He's had this van since 2002 and put almost 70,000 miles on it (and almost all of that on the original battery), despite the best efforts of the dealership to kill it off. Anyway, it was cutting out and generally not working properly, must have been a nightmare to drive, and could well have stopped altogether at any moment.

A quick look at the commutator confirmed the problem: there were two scorched segments opposite each other. When revved up, a worrying crackling arc appeared at the back of the brushes! No wonder the controller wasn't happy! I recognised this fault immediately because unfortunately I had another one go just like it a month previously, and got an expert diagnosis from Jim Husted of Hi Torque Electric in the States (very helpful guy!).

We swapped out the motor in record time, got it finished by about 9PM ready for Steve to begin the return journey. He set off early on Friday morning and arrived back home on Saturday night. Not bad going!

On holiday

Two whole weeks off, to work on my project? Not a chance. Two car MOTs to do, a solar heating panel to install, and, you know, holiday stuff..

Still, I got a bit done today. I was a bit stuck for what to use for the rear end. Motorbike? Sierra? Herald? Those seemed to be the choices, and I do not have any dead motorbikes lying around. The Sierra stuff was a bit heavy and the driveshafts don't stick out far enough before turning into a CV joint.

So I decided to go with the Herald rear hub. After dismantling one, I found that it does in fact have two bearings, so it's not as unsuitable as I first thought. As well, it's not too heavy.

It's only supported on one side, so I've used heavier tubing and it will have plenty of triangulation. The motor goes in the gap between the two tubes at the chassis end, and the spring will act on the upper tube. Probably.

Now I need to choose the pulleys. Or should it be chain drive? Decisions...