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Heads up...Nardini lathes 'n phase converters

5652 Views 10 Replies 6 Participants Last post by  schromf
Just wanted to send out a ‘heads up’ to possibly save someone else some grief.

I recently purchased a Nardini 14x40 lathe in pristine condition from a retiring machinist. :D These suckers, by many accounts, are a great precision lathe. My glee, however, has turned into a bit of frustration, as I try to get the thing wired up and running.

I do not have 3 phase available in my shop, so I’m dependent on phase converters. It turns out that Nardini lathes do NOT work with static phase converters, according to Phase-A-Matic and another converter company. They have a funky Brazilian motor that draws greater than normal load at start up. A rotary converter is needed, which would normally be no big deal, as I already have a 5 HP rotary for my Bridgeport.

The icing on the cake is that the good folks at PhaseAMatic tell me that a 15 horse! converter is needed to run the Nardini’s 6.75 horse motor, due to peculiarities with that particular motor!:eek: I’m not looking forward to buying another rotary at this point, along with the extra noise and power draw, but it doesn’t look like I have many options.

Moral of the story is, if you’re buying 3 phase machines that will be run on some type of phase converter, check with the converter manufacturer to be sure it’s a go. Apparently, Nardinis are the rascals of the converter industry…a little homework on my part would have saved some grief.

Anyone with any secret voodoo tricks on getting Nardini’s to run on static, I’d be forever grateful for your help! Or maybe a good, cheaper source for quality rotary converters other than MSC/Enco?

Stan
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Stan, you probably shouldn't try to run a lathe on static converters - especially one with that big a motor. I once had a rotary converter made by a company called Anderson Phase Converters in Gilbert, AZ. They were a lot more reasonable than the big supply houses. You might also check with a local machinery sales and service company. A local machinery service guy in Phoenix has helped me find things that they don't carry on several occasions. Good luck!
 

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I was told by a reliable sourse that Enco motors draw more than usual because they skimp on the windings.

We have a nardini and I was disapointed to find you have to buy change gears to cut a 40 pitch thread. Of course the gear is over 100.00 (goes without saying.)
but I really like the machine. it is indeed befy.

Seems buzz boxes are not the "thing" in phase converters.

A guy we bought an older Harding super slant from blew a monitor and a board by using a rotery converter that he " saved" money on. :)

Good luck
it is good iron though.

perhaps a motor would be cheaper?

geo
 

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phase converter

Use a static phase converter to start your 15 HP 3 phase motor. ( you could do it with a rope like on an old style lawn mower) The 15 HP motor once moving will create the third phase once it is moving. Wire it so the static can be turned off ( out of circiut )once the 15 horse is up to speed.

I have my whole shop 2 mills, lathe, 2 punch presses, air compressor wired that way on a 25 HP motor works great. One of my my mills is a 440 VAC and I delta wire two tranformers ( use two transformers instead of three for the the three phase).

Lathes are a little hard to start as they start under load, air compressors are a lot worse.

Look around for either a used mining machinery, or industrial machinery the motor should be around 100-175 used. The static converters are a last time I checked under $200.

Rewire your bridgeport and sell your existing rotary and you should come out ahead on the deal, and be able to run your whole shop. For my money though I would go bigger than 15 HP and look at a 20-25 HP. If you ever plan on a big compressor it will need it and I like to overate my electicity and not run at full effiecieny ei: its better to be @ 50% load than 85-90%.

I had a Harding lathe for a while before I sold it and it worked fine. The monitor or circiut board are sensitive to HZ and a cheap rotary that was out of phase prpbably was the culprit. Not I said wire the static so it can be turned off. The static is nothing more than capacitors kick starting a motor, but they also work to keep it in phase 60 HZ. If the caps were bad or designed wrong they constantly correct the motor out of 60 HZ. Bottom line your lathe doesn't have a monitor or electronic gizmo's to worry with so it is just motor electricity theory, simple stuff.
 

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You might look into a variable frequency drive. Some of the smaller ones will turn single phase power into true 3 phase power and it can be used as a variable speed control to boot. I used to have a Bridgeport clone with a 3 phase pulley head. I ran it with a variable frequency drive and rarely had to change pulleys to change speed.
 

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Discussion Starter · #7 ·
Thanks fellas for all the input!....you've all given me something to chew on and sort out.

Ted - Roger that on big motors and statics. Do you keep your rotary in another room, separate from the shop? Hope the move went well. I'm bummed I can't bug you anymore when I come down for class... Guess Don and Chuck will have to put up with me alone :biglaugh:

George -
perhaps a motor would be cheaper?
Do you mean A.) a new motor for the lathe or B.) a 'home brewed' converter using a 3 phase motor? Bummer about the 40 threads, thought I only had to change gears for metric. Glad to see another smith using one of these...I'm sure you're on 3 phase so you don't have my issues. Lilja uses one of these to chamber all his barrels.

PvtColt & schromf - is this sorta what y'all are talkin' about? See method #2
Phase a matic.com

Dave - thanks for the VFD tip....will look into it.

Thanks again,
 

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Yep, thats it. But put a switch to take the caps out of circiut once the motors going. I start my three phase with a motor starter get the motor running then turn off the switch for the phase o matic (same brand I used, I bought it used ). The switch protects the phase o matic cause it only starts a motor that isn't under load.

That way you cant burn up the phase o matic ever. I have put the same setup in my garage cause I have a old 18" three phase table saw, been working for over ten years.

If you haven't figured it out I am a big old machinery nut, I buy restore, and occasionally sell ( only what I don't need ) machine tools. There are always better buys on three phase equipment cause the average joe weekend garage mechanic can't use it. Plus it is real tools not hobby shop quality. My Gorton mill cost Hughes aircraft over $30,000 new I bought it in very good shape for a little over $2000. My bridgeport I picked through 30 mills when a manufacturer was replaceing their mills with new ones, it holds under .007 across the table, not as good as the Gorton but it is a bigger table.

It sounds like your lathe fits your needs it just needs details sorted out that I know are a pain in you know what. Is it gear driven or belt driven? if it is a belt driven lathe you can disengage the belt ,start up your power ( no load condition ), then reengage the belts. It will start up the lathe just fine and if you don't use it every day for two or three years it won't be a problem and you can still work with it. I wouldn't try that on a gear driven lathe though you will damage it and it will cost a lot to fix.
 

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Stan, The new shop's got three phase, so I left my rotary at Hans Vang's new shop in Chino Valley. Sometines if I open a window at the new place though, I can still hear it running:D

It's awfully nice to have a lathe and a mill running at the same time and still be able to listen to the radio.
 

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Discussion Starter · #10 ·
OK, today I learned that 2 speed motors, like on my Nardini, supposedly don't work well with static converters. This from one of the big converter mfrs. They say you can sometimes get one speed or the other to work, but usually not both. YMMV.

Ted, thanks for pointing out Anderson in AZ, they are in fact much less than the big guys. I'll probably go with them, or try and rig up my own like schromf suggested. As a side benefit, Anderson used to be a Nardini dealer, so he knows the machines and what I'll need. Glad you don't need a phaser in your new shop. Oh, and that could be MY converter you're hearing! That or my compressor...that thing near about gives me a heart attack when it kicks on unexpectedly!

schromf- It's gear driven, but thanks for the idea. Sounds like you've got quite a shop there...I thought I'd gotten some good deals on machines, but you've got me beat for sure! Thanks for the encouragement.
 

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Keep your eyes open and look constantly, its the best way to find good machines. I would like to replace my lathe but just haven't run into one I figured was worth getting rid of my old Southbend for. Every time I find on they are either way too much money or beat, and gear head lathes with bunged up gears cost a ton to fix.

Durango is a little out of the way for machinery look in Denver or Pueblo. I know it stinks to truck it home but you will have better choices. I hauled my 18" saw out of Denver to Idaho I had been looking for ever in my neck of the woods just couldn't be found.

Another place to find good equipment is when navy shipyards sell their machinery. The yards always had full machine shops and I have seen some really good pieces come from this source. I had a horizontal mill I really liked that came from a yard, only let it go when somebody made me a offer I couldn't refuse and I bought my Bridgeport.
 
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