Lathe's not working, seeking advice

[TRA]

So, I fixed the VFD...

I bought a rotary. Works like a charm!

Thanks to all that offered advice and assistance. Much appreciated.

Now that's using your head. VFD's are fine, we use a ton of them, but running a lathe is not a good application for a small light duty drive. We have found most of the cheap drives fault just because they feel like it. We have a brand we use and have never had one take a dump. It's a Yaskawa brand.

A vfd on a drill press is a good use for one or big fans in buildings, etc, etc,etc. 3ph is the best, a rotary is the only option for 2nd place.

Programming a VFD is similar to tuning a servo drive and motor. It's more Black Art than an exact science.

 

[Bully]

Is the VFD for sale? I might be interested depending upon what it is and condition.

It will be. I sent it back to Teco/Westinghouse as per them to make sure that the VFD is not at fault. As soon as it makes its way back to me, I'll be posting it for sale.

It's a TECO/Westinghouse FM50. I bought it 4 months ago, got it wired up and... nada. Hence my purchasing a rotary.

 

[223Randy]

Just a dumb question, what hp is the lathe and the VFD --you have to de-rate the vfd by about 50% when single phase to 3 phase

 

[Bully]

Just a dumb question, what hp is the lathe and the VFD --you have to de-rate the vfd by about 50% when single phase to 3 phase

Motor on lathe is 3hp
VFD is for a 3hp. When I called and asked, I was told that that VFD would be the ticket. I assumed that they know what they're talking about so I didn't do any further research. Might be my bad that I didn't.

No matter. It's running now. That's all that really matters to me.

 

[GenePoole]

Just a dumb question, what hp is the lathe and the VFD --you have to de-rate the vfd by about 50% when single phase to 3 phase

Where did you come up with this? The dealers I've contacted say that if the VFD is rated for X HP, then you can use up to and including X HP motors. The 1ø->3ø conversion shouldn't matter as the HP rating is for the output.

 

[Papa Charlie]

So, I fixed the VFD...

I bought a rotary. Works like a charm!

Thanks to all that offered advice and assistance. Much appreciated.

What is a Rotary? Is this a motor controller?

 

[TRA]

What is a Rotary? Is this a motor controller?

It is a phase converter based off of a 3ph motor.

In a nutshell a 3ph motor is wired into a 1ph supply. The motor is then started by various means and will run on that 1ph. The 3 legs of the rotary generate the 3ph.

A little tip, if you have a small 3 ph lathe, mill, drill press, you could get by in an emergency running the machine, You can use a pull cord like on an old lawnmower and spin up the spindle and power up the motor. Granted it will be derated, but is still doable in a pinch.

I used to run a full CNC shop, using a 25hp 3ph motor to generate the 3ph. Rotary converters are eezy peezy to build. And cheap too

 

[carlsbad]

What is a Rotary? Is this a motor controller?

I have a 10 hp runs my entire shop. Although with me there by myself generally only one machine runs at a time. But it is sized for 2. (10HP)

https://www.americanrotary.com/products/view/ar-pro-series

--Jerry

 

[carlsbad]

Motor on lathe is 3hp
VFD is for a 3hp. When I called and asked, I was told that that VFD would be the ticket. I assumed that they know what they're talking about so I didn't do any further research. Might be my bad that I didn't.

No matter. It's running now. That's all that really matters to me.

It is possible that the electrician knew it was undersized and instead of saying "You really need your VFD rated at 2x the HP of your equipment." he just said nothing. Because if he had said that, you would have sent him away while you exchanged it, he wouldn't have gotten paid. If he had asked you for a service fee you wouldn't have been happy--or at least most guys wouldn't. Some guys would have gotten frustrated. Then when the right one got here it is human nature to call a different electrician since this guy is now associated with a bad day you had when you figured out you had a problem--subconscious, but many people will go with it. So a lot of contractors will just keep their mouth shut and do what they are asked. I don't think it is right. I feel it is my responsibility to tell a customer the bad news. But sometimes I never see them again.

Now I'm not saying you would have done this. I'm saying it may have happened to him before.

--Jerry

 

[TRA]

I have a 10 hp runs my entire shop. Although with me there by myself generally only one machine runs at a time. But it is sized for 2. (10HP)

https://www.americanrotary.com/products/view/ar-pro-series

--Jerry

The more motors running at the same time makes the system work even better. All your motors add to the motor starting the chain.

 

[223Randy]

Gene,
Do a little research and you will find that when you are supplying 1ph power into a 3ph output vfd the hp must be de-rated (it's not 50%) it is actually the rated hp\1.73 which for a 5hp rated vfd would be roughly 3hp motor.
If you are supplying 3ph power then it is 100% hp rated.

The only rotary phase converters i have been around sound like another motor running, some louder than others. I have mine wired as others have suggested, directly to the motor, and used my for\rev switch for for\rev lathe operation, and added a variable resistor to control speed, right from the front of the old heavy 10

Randy