New SB Owner - really don't know squat but learning - Reverse question

As the title says, I just acquired a 16x7 2-DW SB lathe. I have it running and in fact used it a little tonight. My current question is about how to reverse it (not that I need to reverse it now, just want to know). The lathe has a lever on the top; to the left is fwd low and high, to the right it says Rev. When I put the lever in the "Rev" position the motor hums but the head does not turn, it acts like it wants to and in fact actually did once but now does not turn. I am wondering of I am supposed to be move some other lever or if there is a problem.

I am sorry if this is a very "newbie" question, I have looked for manuals and online information but haven't found anything that addresses this.

I deeply appreciate any assistance in this in advance. I am attaching a picture of the lathe overall and will post more specific pictures if needed.

It most likely will need to be a 3 phase motor to reverse, since it hums but doesn't turn that tells me you've got the correct motor but it's likely wired incorrectly. 3 phase motors humming without turning is usually incorrect wiring IIRC. Somewhere either something is backasswards or there's an open phase. Are you trying to single phase the motor?

We need to know a little something about the motor that's powering the lathe. Since it looks like a home rather than an industrial setting I'm assuming that you do not have 3 phase power. The symptoms you describe suggest that a single wire has come off inside the Fwd-Rev control so that the start winding is not being connected in the reverse direction. Have a look inside the box to see if everything is connected. The fact that it runs forward indicates that the motor is not the problem but that something is wrong with the connections for the reverse direction. I believe this would also be the case for 3 phase power since if the motor runs in one direction it should work in the other direction if it gets hooked up correctly.

Yes you will need to tell us what motor you have on that lathe, it left South Bend with a 3 phase motor...

Thanks for the responses; the lathe retains its original SB 3PH motor. I am using a 5HP RPC with this machine, however I will go back and check the wiring from the RPC to the motor to see if something is disconnected or off.

Looks like a useful turret lathe (that is what the "2" is for) add on - lever operated rotary switch on back - dealing not only with Fwd / Rev, but also two speeds - resulting in a great bundle of wires in a metal box - the contacts of which started getting worn out nearly 80 years ago trying to win a war 24/7/365

See Pdf Page 32 from 1942

http://www.wswells.com/data/catalog/100B/cat_100B.pdf

I agree, I have already been in contact with Steve about this and he provided me a lot of information about this lathe to include where it was sold in 1942. I am looking forward to learning the machine and using it.

I went through the wiring connections and everything is connected and as I said, it works in the forward speeds correctly. As mentioned, when the lever is placed into reverse, nothing happens except that the motor hums as if it is trying.

One thing I definitely need to address is lubrication, no idea when the last time it was lubricated. Any advice/suggestions as to what to use for this?

On the back side of the lathe where the motor and gears are housed, there is a square bolt with a lock nut, can anyone tell me what this is for and how it should be tightened?

Hello Mike,
Welcome to the South Bend forum.

Sorry I haven't got back to you, work is taking just too much of my time these days, LOL

As John stated, the old drum switch might look a bit FUGAZI when trying to see the rotations and connections if it's stacked.
As suggested, a VFD will be your friend in this situation and you won't need the RPC.
But word of caution, wear electrical gloves and use insulated screw drivers.
This motor should have 6 leads, T1 through T6. For information on 2 speeds and reversing, when in low speed forward the L1, L2 and L3 leads from the RPC would connect only to T1, T2 and T3. to reverse we would switch L1 and L2. when running in high speed forward, T1, T2 and T3 are shunted together and L1, L2 and L3 are connected to T4, T5 and T6. again to reverse L1 and L2 are swapped.
This is the most basic explanation of the older 2 speed 3-phase reversing motor I can give as to the drum switch and it may not even be correct, you will need to confirm visually that this motor and switch are wired this way.
Please check the voltage out on the RPC to confirm you have not lost a leg, if not then look closely at the reversing tabs and contacts for corrosion and blackening, heat damage and like-wise.
When you pull the cover off the drum look for the tag or wiring diag if still there, send me photos, I'll be ohd30, all weekend off.

Steve

Steve,

Great to hear from you and thank you for the information. I confirmed that everything is getting power, basically out of the 3 legs I am getting 237-240V. I am attaching a picture of the connection box for your view enjoyment.

IMO it seems like something mechanically is stopping the motor from running in reverse but it is more of a feeling than actual knowledge. Everything else on this machine works as it should (from what I can determine).

The machine was not rewired when it got here, it was in an operational shop where it has been for 40 years, the wires were disconnected from the wall and that is what I used to hook it up here, so I did not go into the wiring on the machine at all.

I completely realize that diagnosing a problem via the internet and a forum is challenging to say the least and I am very appreciative of everyone's comments, suggestions and advice.

VFD is an awesome choice for running a 3 phase motor on your lathe. They can be had for as little as $140[ish]. They can be powered by single phase 110v or 220v if that is what you have available. Speed and direction can be controlled by a switch and potentiometer (either remotely or directly from the unit). Ramp up and down speeds are programable...

They can be intimidating at first, but a little research and patience and you can have one wired up and running your Lathe in no time.

Since it seems the rotary switches' wiring has not been disturbed, it is very likely the contacts are needing some help

Thumbnail is a giant Westinghouse rotary switch - the heavy copper contacts of which are thoroughly eroded away

my experience mirrors Mr. Oders suggestion, 90% of the time can be traced to dirty/corroded switches not making good contact.

Mike,
Disengage the drive belt and turn the motor by hand, forward and reverse, same thing with the headstock spindle with the headstock shifter in neutral center position. if all is free, disconnect power and swap L1 and L2 at RPC output, leaving the speed selector in low forward without belt tension. the motor should reverse. post results. We know the forward contacts have continuity, so we will use those to narrow down the contact issue if free movement issues are not found.

Steve

Thanks again for the comments and advice.

I am already running a 5HP RPC so I am not real excited about getting a VFD at this stage.

I will look at the contacts very closely and see what it going on there.

Steve - I will do as you suggest and post the results.

Stand by

I have a 6' bed version of this lathe. It's 2-H turret lathe. I have a thread on mine here:
South Bend No. 2-H Turret Lathe 16"x6' Restoration

Your electric motor should be using two drum switches on back side. That's because each drum switch has three positions. Off in center position, than each side can swap how each of the 3 leads connect to motor. One switch can do high and low, one reverse, though not necessarily in that order. Side note, that is a two speed motor, a regular 3 phase motor won't give you high and low speeds and is wired a little different.

Since your fwd is working, the motor should be fine. Reverse is just swapping any two, of the three leads for the high speed wiring, or any two for the low speed wiring. Depends if you want reverse to be high or low speed. My reverse is high speed, as thats just how it was wired when I got it. If you got a multimeter, check voltage between any two legs to read rated voltage, guessing 208-220v. by process of elimination, check voltage at all three legs, two at a time, to figure out which leg is missing voltage. at motor, before and after the switch, etc. But I would guess one leg has a bad connection at switch, or a broken wire. Try reading motor data tag as well, just to insure you're using correct voltage.

You're right about the needing to lube. There's more lube points on this than you can imagine. Including the pulley assembly in motor housing directly above electric motor, should have cups on both end bearings. That turret end has a ton of lube points all over, as well as the whole machine. Pretty much anything that moves. You'll be using a thumb press oil can quite a bit. I'd change the oil in apron and turret gear box at a minimum too, if you're not intending on tearing the machine down for a good cleaning.

That rod hanging down from chip pan, plus the light switch on the leg of tail stock end, tells me it originally had factory coolant set up. Do you have the coolant tank or mounting bracket for it ? If you don't might check again from where you got it. You'll probably see a drain in chip pan hidden inside the pedestal that hold bed up as well.

Another fyi, you won't really use reverse too much if ever, but nice having options. Just keep in mind, the back plate which looks like is part of the chuck, chuck bolts to it, well the back plate is threaded onto to spindle. In reverse, with enough torque to whatever you're doing, it is possible for the chuck with back plate to unscrew right off the spindle. Now if chuck and back plate haven't been off in 20 years, that'll probably never happen, just keep eye on chuck real good when reversing with electric motor.

Thanks for the information. Yes I have the cooling system for the lathe however I do not think it has work for a very long time, it certainly isn't wired up.

I took a look at the rotary drum tonight and the contacts were pretty bad. I cleaned them up but it had no effect, that said I am going to look at it harder tomorrow in day light.

I finally got a chance to really investigate the reverse issue and did as you (Steve) suggested. The motor was fine in either direction. I had cleaned the terminals on the rotary switch several times actually and that didn't seem to make a difference but then I really took a hard look at them and they seemed like they were not making real solid contact, plus every once in a while it would work. So, I really got in there and cleaned both sides plus I "tweaked" the contacts a little and "bam" it works!!!

So, on to the next question, does anyone know where I can get the bearings in the hand collett? I took it a part and one ball bearing is missing. I am pretty sure I didn't lose one as the grease that was there was pretty sticky but the very bottom bearing slowly would drop out. According to the parts book, I believe it says the bearings are 172x20 which I would think was the size.

Here is a picture of the hand collett I am talking about.

To answer your question directly, might try Ted on this forum, or a bearing company using the bearing number with maybe a cross reference depending which bearing company.

To give you food for thought, the collet set up is an accessory. A nice accessory to have, but you'll be using usually one of three things at a given time. A chuck, a drive plate, or collet assembly. Not knowing what your intentions are, i would guess a 4 jaw chuck set up would be your best and most used item.

I think most people leave the collet arm off machine until you actually go to use it, there's an eye-hook deal you can hang it from usually around a collet rack if you have it, or get it. To use collets you also need a thread protector which goes in place of chuck, plus the taper adapter for collets that slides into chuck side of spindle.

Pretty sure you'll have a 2 3/8-6" spindle thread, though you'll want to pull chuck and verify. You can get 7 or 8" back plates on ebay for that for about $80:
8" Semi-Machined Threaded Back Plate 2-3/8"- 6 For All Plain Back Lathe Chuck | eBay
As well as a 4 jaw chuck if you were inclined. For chucks I'd recommend measuring ID of spindle through hole and make sure chuck through hole is the same size or larger.

Thanks for the information, good to know. Right now my "intentions" are a bit fluid, I am a car builder and gun smith but to be very honest I do not intend to do much gun work on the lathe in the near term but we will see.