Restoring a Myford Super 7 Lathe (Part IV)
The lathe is done! Wow it took long enough. Quick recap (please see part III for the full story)
There were a few parts missing after we finished the rebuild. Parts included a gib strip for the top slide and a spacer for the main spindle. Unfortunately you can’t run the machine without these parts, so another order from myford was needed. At the same time I ordered a dust cover and some other miscellaneous bits.
There was a motor include in the auction, it needed some work, like everything else. But there was no motor controller to be found so we needed to build one.
Motor controller
The controls consist of a Direction switch (forward, reverse) a Start button and a big mushroom Emergency stop. Also there are two 18A 240v contactors for the actual motor switching. Below on the right are the control switches, on the left are the two contactors.
Have a look below at how the motor and controller is wired up to allow you to change the motor direction, but basically you change the polarity on the start wiring to change direction.
Above you can see the finished wired up control box, all that’s still missing is the incoming power cord.
Testing
Once the final few parts and motor where installed it was time for some testing. We just found a large steel bolt then tried to round the head and cut a bit of a shaft out of the threaded bit.
We definitely need to get some sharper cutting tools, but the one we had did the job OK. You can see below the final result, not to bad for the first test!
What’s left?
There is lots and lots of tweaking and adjustments left to do. All the slides need to be tightened and aligned, there is also a bit of play in the cross slide lead screw. I’m not sure how much we can fix or if it’s going to need to be replaced. And we definitely need to get some new cutting tools.
So that’s it, all done. We now have a working metal lathe in the workshop. If you want to go back and see how things came together, here’s all the posts.
Hi Stuart,
Great work you’ve done! Respect!!!
I noticed your Motor controler with great interest!
I bought a Super 7 last year and I would like to get rid of the dewhurst switch for safty reasons. Also the machiene isn’t connected yet.
Could you tell me the technical details of the parts I need for the motor controler.
Also a wireing plan how to conect everything. I noticed that 5 wires (2 red, 2 black and 1 earth) are comming out of the motor. How will they be connected to the controler.
Well, you will have noticed that I haven’t got a glue about electrics therefore I would hand over the information to a friend of mine who can help me with it.
Greetings from Germany
Stephan
I’m just guessing about the motor wiring, you might want to ask you friend for a hand.
1. Parts used: 2 x Contactors (look for ones with the main contactor and 2 normally open switches for interlocks) 2 x Normally open push buttons, 1 x 2 Way selector switch. I bought all this at the local electrical wholesaler so I don’t have any makes or models. If you want to spend a little more money you can buy a pre-built motor controller in a box with everything.
2. The 5 wires out of the motor are probably, Live & Neutral for the main windings, Live & Neutral for the start winding and Earth. See the S and M in the drawing above for how to connect them.