Well my wish is finally coming to. i have a big grizzly gun lathe on the way. Now i need to figure out how i want to convert to three phase. vfd or rfc?? i know there are a few folks here who have this machine, if you guys dont mind please tell me how your set up. thanks lee
Gunsmithing grizzly G0509G
- Thread starter skeetlee
- Start date
I have a 7.5 HP three phase rotary convertor, wired to a three phase box, with breakers for the 509G, a Bridgeport, and a surface grinder.
I have another rotary wired to a 240/480 step up transformer, to supply 480-3ph to a Hardinge lathe, I got this rotary on the cheap, so I used it rather than wire the transformer to the original rotary.
The big Grizzly has a pretty good size motor on it, since I run it the slower motor position 100% of the time, the 7.5 is plenty. Uses more current on high BTW.
You can't go wrong, if you get a minimum 7.5 HP unit, and have breakers for each piece of equipment. Also, please, remember to ground everything - this is very important for safety, this stuff can kill you if it goes to ground thru you. Get a real electrician if you don't understand wiring completely.
I have another rotary wired to a 240/480 step up transformer, to supply 480-3ph to a Hardinge lathe, I got this rotary on the cheap, so I used it rather than wire the transformer to the original rotary.
The big Grizzly has a pretty good size motor on it, since I run it the slower motor position 100% of the time, the 7.5 is plenty. Uses more current on high BTW.
You can't go wrong, if you get a minimum 7.5 HP unit, and have breakers for each piece of equipment. Also, please, remember to ground everything - this is very important for safety, this stuff can kill you if it goes to ground thru you. Get a real electrician if you don't understand wiring completely.
I'm running a 2.2kW Hitachi WJ200 on my 3HP TOS lathe:
https://www.driveswarehouse.com/p-2527-wj200-022sf.aspx
Works beautifully. The only downside is that there are literally hundreds of configuration settings, but it's set up out-of-the-box to run pretty damn well with a minimum amount of setup.
Head MB's advice - you do not want to become the best path to ground.
https://www.driveswarehouse.com/p-2527-wj200-022sf.aspx
Works beautifully. The only downside is that there are literally hundreds of configuration settings, but it's set up out-of-the-box to run pretty damn well with a minimum amount of setup.
Head MB's advice - you do not want to become the best path to ground.
I have been using a American Rotary 10hp 220/3 phase converter. This could be a little overkill but I wanted a little extra for a mill. It is running a whacheon 17x40 wired for 220 3 phase. I have to say it has been a good converter thus far. I tested the delivery with our Fluke test unit and it is delivering 120ish on both t1 and 220ish on the third phase. The unit comes with a wall mounting control box and is fairly easy to wire. I added a 3phase plug in between the controller and the lathe.
I was going to mount the "motor" outside the shop but after testing it a little found it to be very quite while delivering well balanced 3 phase power. With both the converter and lathe running one can still have a conversation standing at the lathe.
As I see you may be close to my location give me a pm and you can come see and hear it run for yourself.
btw the lathe has a 5hp motor
R
I was going to mount the "motor" outside the shop but after testing it a little found it to be very quite while delivering well balanced 3 phase power. With both the converter and lathe running one can still have a conversation standing at the lathe.
As I see you may be close to my location give me a pm and you can come see and hear it run for yourself.
btw the lathe has a 5hp motor
R
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Skeetlee,
Here is a bit more info for you. The picture below is a shot of the electrical for the Man Cave.
Center grey panel is the main breaker box, splits off from there to supply the box on the left, connected to the Phase convertor on the left, and the one directly in front. The one in the front, supplies the grey box on the right, a 240/480 step up transformer.
Panel on the left, from the phase convertor on the left, supplies the 509G, and the Bridgeport mill. PLenty of room left for expansion,and as this is a leased building, I can take the panels with me, along with the transformer for the next place.
Next place though, I hope, has plenty of 3 phase built in. Last building I built, had 3000 amp service ( 480V ), not going to need nearly that much!
Here is a bit more info for you. The picture below is a shot of the electrical for the Man Cave.
Center grey panel is the main breaker box, splits off from there to supply the box on the left, connected to the Phase convertor on the left, and the one directly in front. The one in the front, supplies the grey box on the right, a 240/480 step up transformer.
Panel on the left, from the phase convertor on the left, supplies the 509G, and the Bridgeport mill. PLenty of room left for expansion,and as this is a leased building, I can take the panels with me, along with the transformer for the next place.
Next place though, I hope, has plenty of 3 phase built in. Last building I built, had 3000 amp service ( 480V ), not going to need nearly that much!
Congrats 
. Its a nice machine! PM sent and happy chip making.
. Its a nice machine! PM sent and happy chip making.I have a lathe on a rotary and the new PM 1340GT is on a VFD and there is no way I'd do another rotary unless there was no choice, my rotary works great but after chambering a few barrels with the VFD I'd never go back to being stuck on a few speeds, being able to dial in the speed while feeding the reamer has really made a difference for me. Getting the VFD was kinda like getting the DRO, can't go back!!
If a proportional increase in torque is required at low rpms such as for machining a large diameter, a VFD will not provide it as a mechanical variable or gear drive would.
Mr Dalley, you are indeed correct. It's also important to note that prolonged running at low speeds is pretty tough on a motor; not only is it making more heat (due to the increased I^2 * R losses that come from the increased torque required to produce power at low speeds), but it's also not cooling as efficiently since the rotor fan is not turning at the design-intent speed. Conversely, running at higher-than-intended speeds can be pretty tough on the rotor bearings.
That being said, most gunsmithing tasks are so light-duty that it's difficult to anticipate any risk of motor damage, even by doing some pretty silly things with a VFD.
That being said, most gunsmithing tasks are so light-duty that it's difficult to anticipate any risk of motor damage, even by doing some pretty silly things with a VFD.
It looks to me as if a rotary phase is the way to go. From the folks i have spoken with, professional and private, A VFD will not really do what i am needing without a lot of enginering, and money. A simple rotary phase will run the lathe as well as the mill, all on the same unit. Now i just need to figure out what size motor i need for the rotary phase for the 4HP lathe. Lee
With a little engenuity you will be fine. Happy chip making, as it is a nice macheen
7.5 HP works well for mine. It's a package though not a self built.
Over on practical machinist there is LOT of help on that topic.
Er, what?!? The Hitachi VFDs on my mill and lathe literally took less than fifteen minutes to get wired and set up to rotate a motor. They were also less than $350 each.
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Damn are you the guy that beat me to the used one!? Congrats, jealous
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