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+--- Thread: Electric reverse switch for bench lathe (/showthread.php?tid=3720)
Electric reverse switch for bench lathe - Biddlecombe - 04-01-2020
I recently bought a Grayson bench lathe that had laid unused in its original 1946 box for many years and have installed it in my workshop. I want to install a reversing switch in the electric feed and after research came up with the following which stated clearly that it was for use as a reverse switch for single phase 240 v lathe use. However it did not come with wiring instructions and I am no sparky, so I presume that I put green, brown and blue into 3 of the terminals and similar 3 wires coming out 3 other terminals but can anyone please tell me which ones. I cannot find anything online. TIA.
Peter
RE: Electric reverse switch for bench lathe - Zetomagneto - 04-01-2020
Need to see your motor connections.Your motor needs to be reversible, if it is it will have "start" and " run" windings.
RE: Electric reverse switch for bench lathe - dickie65 - 04-01-2020
Its rare to need to run a lathe in reverse for general use.
Its sometimes used in screwcutting on long pieces, if you are doing occasional short threads the lathe can be turned back by hand to keep the tool indexed in the thread.
I agree with Zeto about the motor needing to be reversible.
I hope you enjoy your new lathe.
I have retrofitted a DRO on my lathe which I have found to be a great improvement as I can now flip from imperial to metric measurment at the push of a button.
RE: Electric reverse switch for bench lathe - Biddlecombe - 04-01-2020
20200104_212715[1].jpg (Size: 214.48 KB / Downloads: 266)
This is the best I can get tonight.
RE: Electric reverse switch for bench lathe - dickie65 - 04-01-2020
I have just had look at Lathes.co.uk
You might find that your Grayson lathe has a tumble reverse built in, worth a check before you try some wiring magic.
RE: Electric reverse switch for bench lathe - Bob Culver - 04-01-2020
The switch reverses the start winding. More than just the 2 live mains feed wires are involved. Hopefully the motor will have a cover over the input wires and under this the terminations of the start winding will likely be identifiable and accessible at terminals. These have to be extended to the switch. Internet should explain but perhaps not territory for the unfamilar. If you get it wrong a short could damage the switch. All earth connections must be maintained continuous
If the motor is just some modern adapted appliance motor there may be no provision to readily access the start winding.
I havn't had to think about such matters for 55 years so will leave others to interpret the somewhat obscure diagram.
Lathe sounds like a great find. I know the brand as it was in 1930s from old Model Engineer mags. i recall it being somewhat lighter than a Myford. Several may be interestd in a photo.
(Written before above appeared. Start winding appears accessible)
RE: Electric reverse switch for bench lathe - Biddlecombe - 04-01-2020
Yes it does have tumble but I wanted to have reverse without being connected through screwcutting. I am however grateful for pointing out the rare occasions and maybe it was just a moment of mad desire. I'll try and wire up this switch that it came with.
switch2.jpg (Size: 165.53 KB / Downloads: 244)
Lathe[1].jpg (Size: 233.16 KB / Downloads: 246)
RE: Electric reverse switch for bench lathe - Zetomagneto - 04-01-2020
Tumble reverse only reverses the leadscrew, not the spindle
RE: Electric reverse switch for bench lathe - Bob Culver - 04-01-2020
Looks very useful. The T slots on saddle a great virtue.
Reversing is handy, as long as others do not access and spin the chuck off!
RE: Electric reverse switch for bench lathe - Biddlecombe - 04-01-2020
A few photos, some as I found it early December and now running sweetly.
Lathe first view.jpg (Size: 202.36 KB / Downloads: 229)
Headstock original.jpg (Size: 194.87 KB / Downloads: 228)
Tumble gears.jpg (Size: 227.89 KB / Downloads: 228)
Lathe 2.jpg (Size: 211.78 KB / Downloads: 228)