# I need help picking my new VFD



## thayne_1 (Apr 11, 2018)

Good evening all

I'm working on putting my Bridgeport back together and am waiting on parts. Mill is a series 1 variable speed 2 HP. So I thought that I would start looking into VFD's.
I started reading all the threads that I could. Lots of good information.

Probably too much information.

What I want is to get this mill up and running again and then slowly convert it to CNC. I want the control for the CNC to be able to drive the VFD to control the spindle speed.

Any thoughts on what VFD I  should be looking at??


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## westerner (Apr 11, 2018)

thayne_1 said:


> Probably too much information.



I feel your pain. There is a mountain of info in every related site concerning VFDs. They are very popular, for good reason. I do not have any insight into the CNC portion of your quest, but I have said before, in several posts here and elsewhere- The GS II purchased from Automation Direct was delivered very quickly, the manual was written in English (not a foreign translation of), the price was reasonable, the programming was easy, and the performance has been flawless. I bought a 1 hp unit to power my 1hp Baldor motor on the mill from 1973. Not an inverter rated motor. I do drop from rated motor rpm on occasion, and monitor motor heat buildup with an infrared gun. Gonna stop doing that, tho.  Run times are not long enough to build any heat at all.


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## woodchucker (Apr 11, 2018)

thayne_1 said:


> Good evening all
> 
> I'm working on putting my Bridgeport back together and am waiting on parts. Mill is a series 1 variable speed 2 HP. So I thought that I would start looking into VFD's.
> I started reading all the threads that I could. Lots of good information.
> ...


I was wondering why a series 1 would require a VFD until I read the CNC part.
Do you really need that before you convert to CNC?
I would think the spindle speed would be the last of the changes.
Just my two cents.


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## JimDawson (Apr 11, 2018)

Another vote for for the Automation Direct VFDs.  I have several and most have been working for years.  Just installed a 10HP on the CNC lathe, have a 3 HP on my mill, both GS3 units.  Had a GS2 on the mill until I converted to direct drive, then I went with the GS3 to have sensorless vector control, much wider torque range.  On the lathe, I am controlling the VFD with the computer, on the mill I just turn it on and off with the computer.


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## Briney Eye (Apr 12, 2018)

I'm using a Teco-Westinghouse and a Fuji and am happy with both of them.  I got them both from Wolf Automation.  The Teco has more features.  Both were pretty straightforward to program.  I'm controlling the speed on both using the front panel knob, not a motion controller, so I can't give you any advice there.


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## TomS (Apr 12, 2018)

Have you looked at what Surplus Center?  They have TECO and Hitachi VFD's listed.  Their Hitachi is a 3 HP but priced less than the 2 HP I bought a year ago.  My disclaimer: I'm not a VFD expert and have not researched the part numbers to say whether these drives will meet your needs.  Only posting to make you aware of this vendors offerings.  Good luck with your project.  Lot's of help on this forum to help you through completion.


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## stioc (Apr 12, 2018)

Does one have to worry about the quill/head's spindle bearings when converting to a VFD due to presumably much higher RPM after the conversion? A VFD conversion is on my to-do list, for increased RPM and variable speeds both but I haven't looked into it yet.


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## JimDawson (Apr 12, 2018)

stioc said:


> Does one have to worry about the quill/head's spindle bearings when converting to a VFD due to presumably much higher RPM after the conversion? A VFD conversion is on my to-do list, for increased RPM and variable speeds both but I haven't looked into it yet.



Unless you are planning on running at speeds >5000 RPM for extended periods I would not worry about it.  My spindle just gets warm after about 30 min of 5000 RPM use.


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## stioc (Apr 12, 2018)

Mine runs hot (uncomfortable to hold for more than a few seconds) even at 1830 RPM. My cnc jobs so far have been averaging 15-30 mins but I can see them going much longer. I didn't know if people typical also upgrade the bearings and such when going the VFD route.


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## 4ssss (Apr 12, 2018)

Don't waste your money on a new one when you can buy a guaranteed used one for 1/2 the price.  Radwell.com  (1-800-332-4336) sells all the makes and they stand behind them. I bought a used Lenze AC Tech for my lathe for $100  after buying a new one for my Bridgeport at the full price. Yes you won't get the manual with it, but a call to Lenze and they helped me set it up over the phone, including pulling off a 12v leg for a tach.


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## Splat (Apr 12, 2018)

I'm not doing production work but something like a VFD I would go new. However, that Radwell.com sounds good if they stand behind what they sell. The Hitachi WJ200 series is new to me but I went with it for my lathe because of all the great reviews and it's been around a good while. I've got a Teco model on my mill and while it's been good I doubt it'll last longer than the Hitachi on my lathe, even though I use the lathe more.


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## JimDawson (Apr 12, 2018)

stioc said:


> Mine runs hot (uncomfortable to hold for more than a few seconds) even at 1830 RPM. My cnc jobs so far have been averaging 15-30 mins but I can see them going much longer. I didn't know if people typical also upgrade the bearings and such when going the VFD route.



I'm going to guess wrong bearing grease, no grease, or way too much preload.  They should not run that hot at low RPM's.  I make a lot of parts that run for hours at 3500-4000 RPM and mine stabilizes at about 115°F.  Might be time to send it out for a rebuild, had mine done for about $900 including the 5 bearing mod, and taper regrind.


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