(I just had to watch the Crossrail London Underground program - utterly mind blowing!)
Right, firstly safety. The next phase of this conversion involves dealing with 250Volts AC - it can KILL. If you have not been trained in electrical installation and you want to do something like this, give the job to someone who has! This topic is about how I altered the electrical controls on the Centurion, it is not meant as a step by step instruction of how to do it. As such I have omitted some details that would be obvious to an electrician. At all times, never work on an electrical system unless you have double checked that it is UNPLUGGED!
Sorry about that, it sounds a bit elitist on rereading it, but it really can't be overemphasised.
I totally removed the lathe motor and the FWD/REV switch connections. The VFD draws it's power from the machine main contactor and is earthed directly to the replacement 3 phase motor and the input mains earth. The control terminal connections are shown in the first picture. A 10K ohm variable resistor is connected to terminals 1,2,3 for the speed control. It looks fairly simple to control the direction, you need 24 Volts on pin 9 and 10 for forward and 24 Volts on pin 9 and 11 for reverse. This can easily be done with a centre off single pole switch. However I liked the
multipole rotary switch that was fitted.
Making and fitting a new cam to the first switch bank was fairly straightforward. The photos are a better explanation than my words. They show the original white plastic cam and my new one. A hex key was sacrificed to broach the hole. This rotary switch was easy to work on, blue ones defeat me. I do not have the manual dexterity they require to reassemble, springs and contacts end up in the great blue yonder.
More next time.
Ian