I need some advice for powering a mill

[KnowNothing]

Hi All,

I’m almost done setting up my garage workshop, and I have some questions about powering the mill and lathe. The rub is that I’m virtually illiterate with respect to electricity.

The mill is a 1976 Bridgeport Series 1 with a 2J Vari-drive head powered by a 1.5-hp 3-phase motor. I’d like to maintain the mill’s native speed control.

It was previously powered by a phase converter using a 3-phase motor, and the setup worked like a charm.

I presently have a 5-hp VFD sitting in a box, but I don’t really understand it. I do not want to use its variable nature and just it to output only whatever is necessary to imitate 3-phase line power. Is that possible?

If it’s not possible for the VFD to do that, I have a spare 3-phase motor I can use as the basis for a phase converter, however it’s only 1.5-hp. Is that enough to power a machine with a 1.5-hp motor?

I’ve attached photos of the shop as it sits, with machines unpowered and the compressor shed unfinished.

 

[gray]

I have done just what you are looking to do. My Bridgeport clone (Comet) has a 3 HP/3 PH motor and I used a WEG CFW300 series VFD from automationdirect. I also did the same for the South Bend 13 with a 1 HP/3 PH motor. For this one I used a Durapulse drive, also from automationdirect.

In both cases, I locked the frequency to 60 HZ. I utilized the Forward/Reverse functions by rewiring the existing switches to provide the switching control to the VFD instead of for switching the 3 Phase inputs to the motors. Another nice feature with the VFD is the ability to allow for rapid deceleration of the motor with the use of a braking resistor.

I have two VFD's because the are configured specifically for the motor FLA (Full Load AMPS) which are different for each motor.

I have found the folks at AutomationDirect dot com to be very helpful.

Here are a couple of photos of my setups

I sure wish my shop looked as clean and spacious as your!

Regards,

Dan

 

[benmychree]

Each machine would need its own VFD, with no switching in between it and the machine's motor, I'd think that a rotary converter would be more practical given the number of machines, I think I'd go for one at least 3 HP or more.

 

[Pevehouse]

VFD, I love my vfd setup on my lathe

 

[KnowNothing]

I have done just what you are looking to do.

Thank you for the explanation. Sounds like I have everything I need on-hand to get one of the machines spinning today while I wait for another VFD to arrive.

 

[ttabbal]

I use the variable speed on the VFD a lot. Mine is a step pulley though, so doing that would throw off the speed readings on the vari-drive. I think I'd just set the VFD to 60hz, and run that way. If you wanted to, you could do a small range on the VFD for small adjustments, but I'm not sure it's worth it, or how well that drive handles changing input speeds like that. I would guess it would be fine, but I haven't run one.

The biggest thing with VFD is to ensure there is NOTHING between the VFD and the motor. No switches, branches, nothing. Suddenly switching the motor out of circuit can destroy a VFD. Just wire the switches to the VFD inputs. Then 3 wires motor-VFD. I also like grounding the body of the machine and motor, it's a safety ground and should carry no current unless there is a fault, and the breaker handles the rest if there is. I used a 4 conductor cable and ran the ground back to the VFD which is tied to the house ground.

If you decide to switch later to RPC or native 3 phase, you can always put the drum switch back how it was. With most VFDs you could also feed the 3 phase to the VFD. But that would depend on your specific model. That's more useful if you want VFD speed control though.

 

[verbotenwhisky]

Each machine would need its own VFD, with no switching in between it and the machine's motor, I'd think that a rotary converter would be more practical given the number of machines, I think I'd go for one at least 3 HP or more.

I agree.... RPC

 

[verbotenwhisky]

Hi All,

I’m almost done setting up my garage workshop, and I have some questions about powering the mill and lathe. The rub is that I’m virtually illiterate with respect to electricity.

The mill is a 1976 Bridgeport Series 1 with a 2J Vari-drive head powered by a 1.5-hp 3-phase motor. I’d like to maintain the mill’s native speed control.

It was previously powered by a phase converter using a 3-phase motor, and the setup worked like a charm.

I presently have a 5-hp VFD sitting in a box, but I don’t really understand it. I do not want to use its variable nature and just it to output only whatever is necessary to imitate 3-phase line power. Is that possible?

If it’s not possible for the VFD to do that, I have a spare 3-phase motor I can use as the basis for a phase converter, however it’s only 1.5-hp. Is that enough to power a machine with a 1.5-hp motor?

I’ve attached photos of the shop as it sits, with machines unpowered and the compressor shed unfinished. View attachment 478137View attachment 478138View attachment 478139View attachment 478140View attachment 478141View attachment 478142

Very nice setup.

 

[verbotenwhisky]

Hi All,

I’m almost done setting up my garage workshop, and I have some questions about powering the mill and lathe. The rub is that I’m virtually illiterate with respect to electricity.

The mill is a 1976 Bridgeport Series 1 with a 2J Vari-drive head powered by a 1.5-hp 3-phase motor. I’d like to maintain the mill’s native speed control.

It was previously powered by a phase converter using a 3-phase motor, and the setup worked like a charm.

I presently have a 5-hp VFD sitting in a box, but I don’t really understand it. I do not want to use its variable nature and just it to output only whatever is necessary to imitate 3-phase line power. Is that possible?

If it’s not possible for the VFD to do that, I have a spare 3-phase motor I can use as the basis for a phase converter, however it’s only 1.5-hp. Is that enough to power a machine with a 1.5-hp motor?

I’ve attached photos of the shop as it sits, with machines unpowered and the compressor shed unfinished. View attachment 478137View attachment 478138View attachment 478139View attachment 478140View attachment 478141View attachment 478142

I would recommend a copy of Ugly's

 

[woodchucker]

Hi All,

I’m almost done setting up my garage workshop, and I have some questions about powering the mill and lathe. The rub is that I’m virtually illiterate with respect to electricity.

The mill is a 1976 Bridgeport Series 1 with a 2J Vari-drive head powered by a 1.5-hp 3-phase motor. I’d like to maintain the mill’s native speed control.

It was previously powered by a phase converter using a 3-phase motor, and the setup worked like a charm.

I presently have a 5-hp VFD sitting in a box, but I don’t really understand it. I do not want to use its variable nature and just it to output only whatever is necessary to imitate 3-phase line power. Is that possible?

If it’s not possible for the VFD to do that, I have a spare 3-phase motor I can use as the basis for a phase converter, however it’s only 1.5-hp. Is that enough to power a machine with a 1.5-hp motor?

I’ve attached photos of the shop as it sits, with machines unpowered and the compressor shed unfinished. View attachment 478137View attachment 478138View attachment 478139View attachment 478140View attachment 478141View attachment 478142

nice shop and equip.. thanks for the peek.