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New to me South Bend

. To those not familiar with the machine or set up, they might have inferred variable speed might somehow give them the ability cut metric threads. It does not
I’m sorry, but anyone who makes that inference from a passing reference is a fucking idiot and shouldn’t be operating a machine tool. No need for you to be a net nanny.
 
Thanks for all the input and the help. I will be going for now with a single phase motor at 1750 rpm. It sounds like I should change the pulley on the motor to a 3". If I am reading the thread correct that should not harm the machine and give me a proper speed for this machine.
 
I can then leave the original motor and pulley intact if I every want to put it back. Has the taper key way. Haven't seen one of those for a long time.
 
The 1450 rpm you mentiond is odd, though not impossible, i suppose. But most motors using 60hz or cycles will fall into 1200, 1800, or 3600 rpm ranges. I don't see location on your bio, but I'm assuming USA, we use 60hz here. Its a math problem, x number of poles in motor by 60hz equals speed... I'd like to see a pic of motor and also its data tag. If you get that serial card, it'll tell you what motor was original.

It seems to me that the quality of single phase motors these days is total garbage. I would not choose single phase. Same with the idler motors offered by the rpc manufacturers. They are running a business, they need to operate cost effectively. Their control cabinets are nice, but idler motors are trash. You can get excellent 3 phase motors all day, everyday on ebay, Craigslist, fb whatever for very reasonable prices. And use for your idler, and IF you need a motor for your lathe, that way too, but i think you may be fine with that motor, lets see those pics though.

Get measurements of your motor's pulley diameter, plus the pulley above it as well. We'll make sure you're making rated speed.
1450 goes with 50 Herze - or as we used to say "cycle"
 
Thanks for all the input and the help. I will be going for now with a single phase motor at 1750 rpm. It sounds like I should change the pulley on the motor to a 3". If I am reading the thread correct that should not harm the machine and give me a proper speed for this machine.
You reading correct.

I only do the math for the top speed, but currently, all eight speeds of your chart are running slower than what the chart says. With a 3" pulley and 1750rpm motor, each of the 8 speeds will be pretty much right on the mark of the chart.

You don't have to guess either, you can confirm. If you or anyone you know has a hand held photo tach, put a little piece of reflective tape on the chuck, and shoot it with photo tach once lathe is operational. Run through all speeds, shoot and see the numbers to confirm. This is not 100% necessary, but you can confirm the numbers if you choose.

Running rated speed will not hurt the machine. Just make sure all lube points are actually lubed, but that goes for any speed you are running.

And yeah, absolutely keep the original motor around. Not 100% sure it is truly the original from 1943, but the "made in the USA" on the data tag gives one hope, its been around a while at least.
 
Thanks for all the help. I will check the speeds. Right now I am in a cleaning and re-oiling of the machine before I go further. Will update later with pics and info.
 
To all that have help with me with information since I am new to this. I have a 5441H271 Forward Reversing switch that came with my SB lathe. It had a 1.5 HP 3 phase motor that I have switch out to a 2 HP single phase. I plan to run it on 220 Volts. Can this switch be used to wire up this 2 HP motor and be able to have forward and reverse? If so is there a wiring diagram available? All help is greatly appreciated.
Thanks
Arnold
 
That depends on the motor. There should be an indication on the motor plate if it can be reversed. Usually there are a couple of wires that have to be reversed to do that. I managed to get my motor to reverse with a standard fwd/rev switch usually used for 3 phase motors. It was a lot of head scratching, and I wish I kept the diagram or I would share it. But I have no idea where it ended up.
 
My motor is from Veror and it can be either CW or CCW. Just need to know if I need to get a new switch or if the old one can be used.
 
You should be able to use it. But like I said, it's going to take some figuring. Those 3 phase fwd/rev switches are not constructed the way you would think that would make any sense. LOL. I searched and searched and never found anything I could use. Had to draw it out myself and figure it out. I'll look around for my diagram, but I am not optimistic.
 
Post an image of the wiring diagram of both the motor and the switch (there is usually something inside the cover). We should be able to help you.
 
The inside of the cover on the switch doesn't have a wiring diagram. Just the rating.
Attached is the pics of the motor wiring and the switch. Also did a pic of the ohm's. In off position no reading. Forward the bottom two are switched in the reading and in reverse they are straight across.
 

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What I'm describing here will be a reversing switch but not the power switch for the single phase motor. You'll need a separate power switch for line 1 & line 2. For 220/240 V both Line 1 and Line 2 are hot. You should switch both lines off when turning off the motor.

A 3-phase reversing switch should swap 2 of the legs when switched. The 3rd leg would have the same connection in either switch position (not switched). So you need to figure out which 2 terminals are getting swapped on that switch. That is, 2 of the input terminals to 2 of the output terminals. The bottom 2 terminals in your diagram. Use those terminals to reverse the single phase motor. That's wires 6 & 8 on your motor. Bring wires 6 & 8 to those terminals on the input of the switch. The corresponding output terminals go to where the diagram shows 6 & 8. You won't use the third set of terminals.

The reversing switch has an off position, but don't use that position. When starting, that will just disable the start winding so the motor will sit there and hum until the breaker trips or the motor winding burns out.

I'm sure you know that you need to bring a single phase motor to a full stop (power switch off) before starting in the other direction. You are switching the starting winding.
 
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That is a standard 3 pole, double throw switch, with jumper wires pre-installed. You can rewire some of those jumpers and make this switch work with 220 single phase. I'll draw something up.
 
So here's a way to wire it- modify the jumpers on the switch to be 'L' shaped (blue wires), and bring the line from the wall into the center upper and lower terminals. This will properly switch off both phases in the off position. The middle terminal of the switch will connect one end of the start winding to either phase, depending on switch direction. The other end of the start winding is connected to the 'star' point at the motor.

3pdt-vevor.gif
 
So I have to ask what is the star Point in the motor? And redoing the switch as above it is only switching the L1 and L2 lines to change rotation? The other line 6 stays tied with 2 and 3? Just want to make sure so I don't do any damage to the motor or switch. Thanks for the input and help.
 
Also need to know if I can use 12ga. THHN solid wire between the motor and the switch? I am using a 12/3 SO cord for the plug.
 
When a dual voltage motor is run in high voltage mode, the two run windings must be placed in series, that happens at the 2+3 junction. The start winding then cannot go between L1 and L2, it must be placed in parallel with one of the two run windings. Interestingly, this means there are two ways to reverse the rotation- switch both leads of the start winding (like the directions say), or move one end of the start winding from L1 to L2. If the motor rotates opposite of what you would like relative to the switch labels, just reverse L1 and L2 at the switch.

I would not use solid wire for any machinery, too much vibration and eventual fatigue failure.
 
I will need to get some 12 ga. copper stranded wire. Hopefully today and can get it wired to run tommorw. You are a Jewel for helping me and making it so clear. See why you are a Titanium. Once I get it running I will post some pics. Been cleaning and oiling everything for now. 1942 War lathe that was used and sold to the UNR in Reno. I think it is in nice shape for the age, but will tell when I can do some cutting and see what I get for results.
Thanks again for all the help and support.
Arnold
 








 
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