my new lathe ... Precision Matthews 12x36 ...

[StrikerDown]

The HOT colors do not matter wiring 220v. You just have 2 120v legs and a green equipment ground. Talk about overkill Will 🙂 You could have ran 14/2 to that machine with plenty to spare.

I thought the same thing when I saw the wire size, but then I thought about how he is using it "On the floor" and the extra heavy wire might be a good thing.

That big wire sure is expensive though!

Will,

Wondering if your lathes gearbox lets you dial up the different thread cutting feed rates without removing/swapping change gears?

And do you know if the grizzly you were considering does?

 

[nailbender]

All new appliances be it home or work related if already wired must use a four prong 240 plug until you get into monster stuff.

Most all states are now code at least NC, Ga, SC and any based off of the International code system are required that they have to use two hots a ground and a neutral. I build houses or used to :mecry:and the code changed several years back and was basically homeowner oriented for safety.

dave

 

[wquiles]

Your "extension cord" is wired backwards but it won't effect the rotation of the motor in single phase AC. If it were 3 phase (3 hots) then changing any two of the three will change rotation of the motor due to the phase relationship of 3 phase AC.

Cool, thanks, makes sense about the rotation being OK.

Since you are using an "extension cord" you probably should change the red and black to eleminate future confusion. No it is not code but I understand your concern about the 220V on the floor and being ablt to disconnect. Have you considered running conduit from the panel to the ceiling above the lathe with twist lock drop cord?

I did, but the assistant at the electronics section gave me a weird/bad look when I mentioned it, so I decided to consider this for later, until I can find out better if/how I can do it in a residential environment.

Are there 3 conductors coming from the new machine or 4?

Just 3. The two hots and the return. At the lathe's electrical box, they tied the return to the earth ground - this is the common ground for everything.

The neutral (white) should not be connected to the ground (green) at the machine or any where outside of the power panel on the side of the house.

What you want to avoid is connecting the white and green outside of the panel. It is a safety issue should you ever get the wrong combination of loose connections it could be a killer. This is not very likely but using an extension cord does increase the risk.

This is how things are wired right now:
1) The female 220V outlet is grounded (green wire) to the metal base of the lathe by 5 metal screws - a solid ground.
2) The electrical panel of the lathe has the return wired as the earth ground for the machine. So by the metal-to-metal bolts in the machine, the earth ground from the female outlet is already "wired" to the return wire in the 3-conductor wire coming out of the lathe's distribution panel.
3) Since I wanted a "stronger" ground from the female outlet to the lathe's distribution box, I shorted the green and the white at the male plug that I created for the lathe, so when it plugs into the female outlet, I have an extra solid connection between earth ground and the metal and the distribution box.

This give me an extra path to earth ground, so now I don't have to count on the metal-to-metal connectivity to make sure the lathe's electrical panel, and of course the lathe, are at earth potential. If by some means one or both of the hot wires were to contact the metal on the machine (the parts I would touch during normal operation), the way I have it wired now would allow for an extra path to earth ground, which lowers the chance of me being shocked.

Now, I must admit that I am still fuzzy on the increase risk part by having the extra ground tied to the return at the lathe. Please note that I am not claiming to be an expert, I am not an electrician, and I do really want to understand this better, but I still don't follow why the way I have it wired now is more dangerous than not connecting earth ground. Can you please expand on this some more? Is there an alternate way to wire it so that it would be even better, safer? I though about adding a single thick wire from the earth ground in the lathe's electrical box to the metal base of the lathe, which is at earth potential - is that better perhaps?

If your lathe has only three conductors 2 Hot and a Neutral (wh) you should probably change out the lead to 3 conductor with ground and connect the ground to a substantial chassis ground in the machine.

Per the wiring diagram of the lathe, and by looking at the wiring panel on the lathe, there is a 24V step down transformer, but nothing for 110V. Still, the lamp, and the coolant pump run on 110V, so (and I have to double check) they might just be running one of the hot wires and the return to run those.

I thought the same thing when I saw the wire size, but then I thought about how he is using it "On the floor" and the extra heavy wire might be a good thing.

That big wire sure is expensive though!

That is exactly why I got the wire I got. Extra thick and water resistant. Although it is going to be on the floor only while I run the lathe, I wanted to be extra careful. The wire alone was $44 at my local Home Depot.

Wondering if your lathes gearbox lets you dial up the different thread cutting feed rates without removing/swapping change gears?

And do you know if the grizzly you were considering does?

Yes, I tried it a little bit last night. You can change threads on the machine by using the round dials without having the change physical gears on the machine. I believe the Grizzly allows for the same, but my gears are completely enclosed on its own fluid bath, which is a great thing for wear and noise 😉

Will

 

[precisionworks]

if your lathes gearbox lets you dial up the different thread cutting feed rates without removing/swapping change gears?

With few exceptions, a machine that has a QCGB (Quick Change Gear Box) will never have to swap out a gear -- EXCEPT, it the threading is changed from inch to metric.

Slightly OT ... I snagged a nice motor on eBay last night. Seller accepted my offer, and it cost me just $100.66 (delivered) for a new Baldor M3661T. Nearly identical to my 'standard' M3611T, except the shell & base are heavier, adding about 20# to total weight:

Time to start saving for another VFD😀

 

[Alan B]

...

Just 3. The two hots and the return. At the lathe's electrical box, they tied the return to the earth ground - this is the common ground for everything.

This is how things are wired right now:
1) The female 220V outlet is grounded (green wire) to the metal base of the lathe by 5 metal screws - a solid ground.
2) The electrical panel of the lathe has the return wired as the earth ground for the machine. So by the metal-to-metal bolts in the machine, the earth ground from the female outlet is already "wired" to the return wire in the 3-conductor wire coming out of the lathe's distribution panel.
3) Since I wanted a "stronger" ground from the female outlet to the lathe's distribution box, I shorted the green and the white at the male plug that I created for the lathe, so when it plugs into the female outlet, I have an extra solid connection between earth ground and the metal and the distribution box.

This give me an extra path to earth ground, so now I don't have to count on the metal-to-metal connectivity to make sure the lathe's electrical panel, and of course the lathe, are at earth potential. If by some means one or both of the hot wires were to contact the metal on the machine (the parts I would touch during normal operation), the way I have it wired now would allow for an extra path to earth ground, which lowers the chance of me being shocked.

Now, I must admit that I am still fuzzy on the increase risk part by having the extra ground tied to the return at the lathe. Please note that I am not claiming to be an expert, I am not an electrician, and I do really want to understand this better, but I still don't follow why the way I have it wired now is more dangerous than not connecting earth ground. Can you please expand on this some more? Is there an alternate way to wire it so that it would be even better, safer? I though about adding a single thick wire from the earth ground in the lathe's electrical box to the metal base of the lathe, which is at earth potential - is that better perhaps?

Per the wiring diagram of the lathe, and by looking at the wiring panel on the lathe, there is a 24V step down transformer, but nothing for 110V. Still, the lamp, and the coolant pump run on 110V, so (and I have to double check) they might just be running one of the hot wires and the return to run those.

...

Will

The green safety ground wiring should never carry operating current. It is for fault current only. Tying the neutral to the safety ground causes operating current to traverse the safety ground and can raise the ground potential of the chassis and cause a shock danger, especially when motor transients occur. Neutral is near ground potential, but may not be at ground potential due to voltage drops and unbalanced loads elsewhere. There are various wiring failure scenarios where tying neutral to safety ground at the equipment masks the fault and causes increased risk of voltage on the external chassis. In many cases additional permanent independent grounds to the chassis are used to improve safety.

It is appropriate to tie the lathe chassis and the stand to the green wire safety ground. It is also required to isolate the white neutral from the chassis. The neutral should only connect to internal components that require 110V.

Be safe,

-- Alan

 

[wquiles]

The green safety ground wiring should never carry operating current. It is for fault current only. Tying the neutral to the safety ground causes operating current to traverse the safety ground and can raise the ground potential of the chassis and cause a shock danger, especially when motor transients occur. Neutral is near ground potential, but may not be at ground potential due to voltage drops and unbalanced loads elsewhere. There are various wiring failure scenarios where tying neutral to safety ground at the equipment masks the fault and causes increased risk of voltage on the external chassis. In many cases additional permanent independent grounds to the chassis are used to improve safety.

It is appropriate to tie the lathe chassis and the stand to the green wire safety ground

Don came up to pickup his new 8x lathe this morning, and he has taken the code classes and understands why things are done the way they are (thanks much Don!). He explained in person the potential for a double fault, so now I understand better what to change in my wiring to make it a little bit safer than it is now. I will re-wire that plug to remove the short at the plug, buy a 4-wire conductor to wire a new plug, and tie the green wire back at the lathe's electrical box, to the metal chassis. Still, note that as said bellow, both (green and white) will still be connected at the metal frame of the lathe, but now they will be as close as possible to the actual electronics and provide an extra level of safety.

It is also required to isolate the white neutral from the chassis. The neutral should only connect to internal components that require 110V.

None of my 220V tools allow for this. On the old lathe, the new lathe, my floor drill, etc. - the white neutral/return is always tied to chassis ground 🙁

Will

 

[wquiles]

With few exceptions, a machine that has a QCGB (Quick Change Gear Box) will never have to swap out a gear -- EXCEPT, it the threading is changed from inch to metric.

Slightly OT ... I snagged a nice motor on eBay last night. Seller accepted my offer, and it cost me just $100.66 (delivered) for a new Baldor M3661T. Nearly identical to my 'standard' M3611T, except the shell & base are heavier, adding about 20# to total weight:

Time to start saving for another VFD😀

Yup, you have me convinced already. I played yesterday with the manual levers for speed change on the 12x36 and I hated it (I am too used to infinitely variable speeds!). So not yet, but I will also be saving for a VFD conversion sometime this year 😉

Will

 

[cmacclel]

So Will how loud is the Lathe?

Mac

 

[wquiles]

So Will how loud is the Lathe?

Mac

You know, my next door neighbor came last night as soon as I had it wired, and we played with the different controls somewhat, including various speeds (I hate to use levers to change speeds!). The gears are not even broken in, but bellow 500-800rpm is fairly "normal" and quiet, meaning not loud at all. At the highest speed there was a higher freq. pitch/whine sound to it, and it was a little louder as expected, but I have to do this again once I follow the break-in procedure as it "should" get better/quieter 😉

Will

 

[StrikerDown]

All new appliances be it home or work related if already wired must use a four prong 240 plug until you get into monster stuff.

Most all states are now code at least NC, Ga, SC and any based off of the International code system are required that they have to use two hots a ground and a neutral. I build houses or used to :mecry:and the code changed several years back and was basically homeowner oriented for safety.

dave

I was an indistrial electrician about a hunders years ago so I'm not up on current code, but what you said make complete sense.

I would have bet the Wills lathe had 3 conductor with ground (thats 4).

If it were mine I would hard wire from the panel to the nearest wall in conduit mostly cause I have that stuff sittin around. Or if it is free standing, to aviod the tripping hazard, I would put in a box or drop from above depending on ceiling height with twist locks. It is so much safer than having a tripping hazzard around moving machinery. Also I would replace the cord with a ground conductor. But thats just me.

 

[wquiles]

I was an indistrial electrician about a hunders years ago so I'm not up on current code, but what you said make complete sense.

I would have bet the Wills lathe had 3 conductor with ground (thats 4).

If it were mine I would hard wire from the panel to the nearest wall in conduit mostly cause I have that stuff sittin around. Or if it is free standing, to aviod the tripping hazard, I would put in a box or drop from above depending on ceiling height with twist locks. It is so much safer than having a tripping hazzard around moving machinery.

I will inquire as to what is code for the drop box - I like this path as well 😉

Also I would replace the cord with a ground conductor.

I am doing that today. I will be buying a 4 conductor, 16GA wire and re-do the plug properly, with the extra earth ground tied inside the electronics box to the metal chassis, in a different spot than the current connection point for the return/white wire (even though it is also connected to the metal chassis) 😉

Will

 

[StrikerDown]

You know, my next door neighbor came last night as soon as I had it wired, and we played with the different controls somewhat, including various speeds (I hate to use levers to change speeds!). The gears are not even broken in, but bellow 500-800rpm is fairly "normal" and quiet, meaning not loud at all. At the highest speed there was a higher freq. pitch/whine sound to it, and it was a little louder as expected, but I have to do this again once I follow the break-in procedure as it "should" get better/quieter 😉

Will

You poor guy! It's like changing all those gears on an 18 wheeler! 😗

I just love that mechanical whine!

 

[Alan B]

I was an indistrial electrician about a hunders years ago so I'm not up on current code, but what you said make complete sense.

I would have bet the Wills lathe had 3 conductor with ground (thats 4).

If it were mine I would hard wire from the panel to the nearest wall in conduit mostly cause I have that stuff sittin around. Or if it is free standing, to aviod the tripping hazard, I would put in a box or drop from above depending on ceiling height with twist locks. It is so much safer than having a tripping hazzard around moving machinery. Also I would replace the cord with a ground conductor. But thats just me.

Overhead twist-lock and a separate (redundant) ground conductor sound excellent.

Neutral tied to chassis is a bad idea. It may be old style, but we never do that as far as I know. Seems like a major safety violation. The NFPA 70E regulations don't even allow a person to throw a circuit breaker without proper personal protective equipment - safety glasses and natural fiber clothing (or more depending on the available fault current). Things have really tightened up in recent years. Most electricians aren't even up to speed on the requirements anymore.

If the neutral is tied to chassis, and the neutral opens up, then all load current will be travelling on the safety ground (and the equipment may well continue to operate normally). This can raise the potential of everything tied to the safety ground and create a shock hazard at remote locations from the fault, especially if the safety ground opens up at some remote location). Turning on a high-load 120V appliance (like a compressor) can open the safety ground and cause a fatal shock elsewhere in the house such as the kitchen or bath). The equipment involved can be separate from the equipment that ties the neutral to the safety ground, so this can be quite a mess to fix since ALL neutral to safety ground connections must be cleared, aside from the required utility / house entry connection.

-- Alan

 

[StrikerDown]

Alan,

Exactly what I was referring to.

"It is a safety issue should you ever get the wrong combination of loose connections it could be a killer. This is not very likely but using an extension cord does increase the risk."

You said it much better! :wave:

Damn Will, I wish I could come drool on your new toy! You wouldn't need the coolant pump!

 

[wquiles]

The used Starrett Level came in yesterday, so I spent last night leveling the new lathe. It has a small nick on one of the top plastic corners, but it seems to give repeatable readings, and it is darn sensitive for sure!:

Man, the level is so sensitive that it takes a LONG FREAKING time to get things aligned!. I set the lathe with a slight down taper (slightly lower on the tailstock side) to aid in collecting lubricant on the built-in recovery hole, and of course as level as I could on the actual ways to minimize any twist (this is what took at long time since of course I ahve to check on the spindle side, then the tailstock side, adjust, and then check again, again, again, etc.).

When I started, there was so much twist, that just moving the carriage up and town changed the reading on the level - it is much nicer now (can't hardly see any movement now) thanks to the nice level 😉

One thing I noted is that since my leveling feet have the neoprene footing, the lathe can move a "little" bit when pushed - not enough that you can see it moving (it feels solid), but the Starrett level "can" detect the slight movement. Is this normal and just comes form the neoprene feet, or am I better off with a steel leveling feet and no neoprene?

Will

 

[KC2IXE]

I'd say steel - in fact, I'd say once leveled, the ideal is to grout the machine to the floor, so things don't move

 

[Mirage_Man]

One thing I noted is that since my leveling feet have the neoprene footing, the lathe can move a "little" bit when pushed - not enough that you can see it moving (it feels solid), but the Starrett level "can" detect the slight movement. Is this normal and just comes form the neoprene feet, or am I better off with a steel leveling feet and no neoprene?

Will

That is why I did not use rubber feet. I used solid steel riser blocks I turned on the lathe. The best scenario and one I am not able to do is bolt it to the slab.

 

[TranquillityBase]

That looks like a knee brake 🙂

 

[wquiles]

So Will how loud is the Lathe?

Mac

While leveling the machine I started doing the burn-in procedure, and now that I have been with the machine running longer periods (about 15 min on each of the first few speeds), I can tell that yes, it is louder than my DC powered 8x machine, but not 10 times louder (thank God!). Since my thread/feed box has its own lubrication and it is sealed, there was no noticeable difference in having it running or not.

Will

 

[precisionworks]

Is this normal and just comes form the neoprene feet ...

I use the identical Mason Mounts under the surface grinder. After a few days, the neoprene will compress slightly & take a set. Check it in a week & you may have a very slight movement that needs correction.

One thing nice about the Mason Mounts, they nearly "glue" any machine to the floor, making a lighter machine very stable when turning an unbalanced part. I'd stay with them unless they become a problem. My South Bend is resting on thinner pads under steel levelers, but stays almost perfect from week to week. If you have a critical job to turn or bore, it's worth the time to check & re-level if necessary.