291: Sunday 7th May 2017

The last 2 weekends have been about changing from DC motor and controller to AC. I had the brushes burn out again around Easter time and I figure now is the time to change to AC (no brushes, better regen capabilities). The picture below shows the controller and charger removed with the old motor still in the car. Notice there is only a small gap between the motor and the body.
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I found a company in UK that had some HPEVS AC-50 motors and was able to get me a Curtis 1239 controller for a reasonable price. This works well with my existing 120v battery pack. This is a smaller motor than what I took out and also the controller is a lower rating, but the cost to get performance is too high. I found the low speed performance of the DC motor to  be excessive for my journeys, but the AC system behaviour is so much more configurable with the Curtis controller.
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The motor fixings were the same as the old motor including the 4 threaded bolt holes around the perimeter and the shaft size was the same. The only difference was the shaft was shorter. The old motor had an 11mm spacer to hold the taper lock hub off the motor. This provided the right geometry for the clutch to be in the correct position for the actuator. With no spacer, the hub was rubbing on the motor. With the 11mm spacer, the hub was hanging off the end of the motor shaft. Neither of these conditions was acceptable. My neighbour Luke has a friend who has a lathe in his garden workshop so we went to see him and he made the outer mounting ring 9mm shorter and made me a 2mm spacer This then gave the same distance as an 11mm spacer. You can see in the photo below the hub is lined up nicely with the end of the motor shaft. I had to cut the stepped key to match this length. I inserted the adapter bolts around the edge of the hub before locking the on the motor shaft. I then added the flywheel adapter, then the outer ring and bell housing adapter plate, then the flywheel and clutch in that order. I mounted The motor last Saturday with help from my friend Sandy
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The place where I got the motor from had some other bits that I paid a bit extra for such as wiring looms, shaft key, motor bolts, rear motor cover and this rear mounting bracket. At this stage as shown in the photo I was on my second attempt at marrying my old mount and this new one. I had cut off the bent part of the bracket as my first attempt was to add an extra 12mm of metal to bridge the gap difference with the old mount. I Decided to just use bigger angle section and replace the whole end of the new bracket. I had to cut another slot for the transducer cables on the back of the motor. The bracket is just tack welded in this here.
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Monday night I went with my neighbour Luke to his workshop where he MIG welded the joints, then went over them with a TIG welder to make them look neater as this will be on show. We added 2 triangles on the back and one on the front to provide extra strength and rigidity and help prevent any twisting. These were also MIG and TIG welded. I just need to give them a good coat of paint then it is ready to go back on. We also re-made the drive shaft bearing support bracket to fit this new motor set-up.

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