VFD for Rong Fu mill

[ARC-170]

I was thinking I might like to add a VFD to my Rong Fu RF-30 clone machine. Seems it's not as easy or inexpensive as I thought!

I found a guy on YouTube who used this and a motor from a treadmill on his HF wood lathe. 1. Would this particular group of components work for my machine?

Here's the video:

Here's the components: https://www.galco.com/buy/KB-Electr...C6X2WylgJ-xkIMkJ9sYIy1zKocwVgcKxoCjl0QAvD_BwE

I called a local electric motor place and he told me I need to use a 3-phase motor. He also said that mill motors are VERY specific to the machine and that I'd have a hard time finding a 3-phase motor for my particular machine. 2. Anyone know a source for a 3-phase motor for a Rong Fu RF-30 clone?

I'd like one that has a dial (rheostat), not buttons, and that has an RPM readout. Like this:

The one above is over $1,000, but it gives you an idea of what I want.

This one was just references on a website with no specific info, but is the size and type I'm looking for, but it needs a tachometer. I wouldn't mind adding one separately.


I've seen some posts about VFD's here and elsewhere, but I must confess I'm a little lost. If someone could point me in the right direction I could learn more and get more info. I'm hoping someone has done this and can show me what they did and where they got the parts.

Here is the info for my motor:
2HP
1.5kW
110/220 Volts (I have it wired for 110)
1720 RPM
23/11.5 Amps
single phase, Class E
I think the frame size is 80, but I'm not sure.

Thanks!

 

[DavidR8]

I'm no expert but I believe that a VFD only works with 3-phase motor.
I swapped in a 3-phase motor and VFD on my RF30 clone and am very happy with it.

 

[hman]

I replaced the original motor on my Grizzly G1007 (RF-30 clone) with a 3 phase/VFD. It's actually pretty straightforward.

A treadmill motor would be a lot more difficult to mount, because (at least the ones I've seen and used) they use very non-standard mounting systems. In addition, treadmill controllers (NC60, especially) have a built-in slowdown ramp. I loved the fact that with a VFD (and a braking resistor), I could run the motor slowly to tp holes, and reverse it instantly to unwind the tap. Implementing this on a treadmill motor (even with a different driver/controller) might be a bit more complicated.

One of the main things to watch out for is that the motor shaft is the same diameter as what you already have. (NOTE - treadmill motors have very odd shafts)

Here's the motor data plate:


This is how I mounted the motor. Pretty easy, as the mounting plate on the mill has vertical slots and the motor base has horizontal ones:


For a VFD, I used a 2HP Teco FM50. I think that model has been discontinued and/or out of stock:

Teco-Westinghouse, FM50-202-C, 2 HP, Variable Frequency Drive 230 Volt, 1 or 3 Phase Input, IP20, at Dealers Industrial

Purchase Teco-Westinghouse, FM50-202-C, 2 HP, Variable Frequency Drive 230 Volt, 1 or 3 Phase Input, IP20, from Dealers Industrial

dealerselectric.com

There's a new version of this VFD. It's called a 510 or something like that.

I ran low voltage wiring from the VFD to the original on/off switch on the mill and to a small control box that housed a speed control pot and a (guarded) reversing switch:




About the only thing you asked about that I haven't covered is an RPM readout. There are several possibilities on Amazon or eBay, and they're pretty easy to wire up. You'll need a DC power supply to run them. They generally use either a prox sensor or a magnetic field sensor (magnet included with the purchase). You can attach the magnet to the bottom of the spindle pulley, and there should be room to mount the (approx. 1/2" diameter by 2" long) sensor through the bottom of the belt housing.

Feel free to ask further questions!

 

[markba633csi]

You have a choice of ac motors or dc motors and there are several flavors. The dc treadmill option can potentially save the most money, but requires some sweat equity and a little electrical knowledge. Sometimes it's better to ditch the treadmill speed control for a commercially available unit like KB, and just use the motor
-Mark

 

[martik777]

Biggest issue will be the shaft size mismatch. Mine was 22mm and the used motor was imperial, so I'd have to bore out the multistep pulley, instead I just used a imperial sized single pulley. Loads of used 3 phase motors ~ 1HP for <$50 which is plenty. I have a couple of these VFD's, they work great:
220VAC Single-phase Variable Frequency Drive VFD for 3-phase 2.2kW AC Motor US 4000006533522 | eBay

 

[brino]

@ARC-170 ,

It sounds like the guy at the motor place was trying to up-sell you.

Sure you do need a 3-phase motor to use a VFD, but as stated above you should be able to find a decent used one for $50-100.
I also have a VFD like the one @martik777 pointed to above. It works fine.

As mentioned already, you could get another 2HP motor like your original, but even a 1.5HP wouldn't be bad on that machine.

You can run controls from the VFD to a panel for on/off, speed, direction, and some VFD's even allow running a remote RPM display. However, note that is the RPM the motor will be running, and there are some belts and pulleys between the motor and the spindle.

You care more about spindle speed. So sensing and displaying that is more useful.
There are many low-cost options for that:

https://www.micromark.com/Digital-Speed-Readout-for-7x16-Lathe-and-R8-Milling-Machine
https://www.hobby-machinist.com/threads/machtach-build.66321/
https://www.instructables.com/An-Easy-and-Cheap-RPM-Tachometer-Upgrade-for-the-M/
https://www.aliexpress.com/item/2046899020.html

The Machtach one is interesting because it can display SFM (surface feet per minute) as well as RPM.

-brino

EDIT: it looks like the machtach site is dead.........

 

[DavidR8]

For what it’s worth a 145 frame motor fit perfectly on the motor mount of my RF30 clone.


Sent from my iPhone using Tapatalk

 

[mksj]

I recommend you post a picture of the current motor name plate, and determine if it is a metric sized motor or imperial sized, and the diameter/length of the current shaft. It is very unlikely to be 2 Hp and you are running it off of 120VAC. I also assume it is a base mount as opposed to flange mount. On a 2HP metric motor, 1750 RPM, the frame size is usually 90L with a shaft diameter of 24 MM. Often a major limitation is the shaft size and length, and the frame size does not match the Hp/kW rating. Leeson has new metric motors. they have increased in price by around 30% from last year. They also come with flange mounts if needed. If you can use a standard US frame 145 motor there are a lot more options and at significant savings. Prices have gone up significantly and be careful of shipping costs.

As far as VFD's the FM50 is obsolete and replaced with with the L510. On a 2 Hp motor the model would be the L510-202-H1-U with a 220/240V single phase input.

Teco-Westinghouse, L510-202-H1, 2 HP, Variable Frequency Drive 230 Volt, 1 Phase Input, IP20, at Dea

Purchase Teco L510-202-H1-N 2 HP Variable Frequency Drive from Dealers Electric

dealerselectric.com

Example of a combination package:

Teco-Westinghouse, 2 HP 1800 RPM 230 Volts Input Package, 2 HP, 1800 RPM, 230 Volts, 1 Phase, IP20, 143T Frame, , VFD & Electric Motor Package

Purchase Teco-Westinghouse, 2 HP 1800 RPM 230 Volts Input Package, 2 HP, 1800 RPM, 230 Volts, 1 Phase, IP20, 56 Frame, VFD & Electric Motor Package from Dealers Industrial

dealerselectric.com

Making a control pod is very simple, basically a 3 way rotary switch, a pot for speed control and an E-Stop in a small enclosure. Basic RPM tach needs to be driven directly off the spindle, which can be a bit tricky. MachTach is no longer available and the Tachulator is expensive and kind of clunky. I would pick up a cheap tach on Amazon or Ebay for around $15.

uniquegoods LED 4 Digital Tachometer RPM Gauge Speed Meter Tester 10-9999 RPM with Hall Proximity Sensor NPN Switch Red: Amazon.com: Industrial & Scientific

uniquegoods LED 4 Digital Tachometer RPM Gauge Speed Meter Tester 10-9999 RPM with Hall Proximity Sensor NPN Switch Red: Amazon.com: Industrial & Scientific

www.amazon.com

 

[hman]

It sounds like the guy at the motor place was trying to up-sell you.

Definitely!

The Machtach one is interesting because it can display SFM (surface feet per minute) as well as RPM.
-brino
EDIT: it looks like the machtach site is dead.........

Ya. Used to be on Yahoo groups, also moribund. The originator is now on Thingverse. No longer selling the PC boards or kits, but has made the design open source. See below for details:

MachTach Machine Tachometer by henryarnold

This Thing documents the MachTach machine tachometer which was a product I used to sell. I have stopped selling MachTach kits so I am now making the design open source so that people can make their own tachometers. Please read the documentation for information on how the MachTach works, how to...

www.thingiverse.com

There's been a recent thread here about the MachTach, including some interest in doing a bulk buy of PC boards:

Mach Tach?

Anyone have any idea what's up with Mach Tach? Their site just says "Sales of MachTach kits has been temporarily suspended."

www.hobby-machinist.com

I had a vintage MachTach kit gathering dust in my shop. Put it together last month, and LOVE it. Definitely worth getting one if you can.

PS - Many thanks, @mksj ... I'd forgotten the number of the "updated" FM-50.

 

[ARC-170]

Thanks so much everyone! This is awesome. I found the Electrical Issues section after I posted. Not sure why nothing showed up when I did a Google search.

For the controls I'm looking for something like the 3rd photo in post #3. All hard switches and buttons, no membranes. If I understand correctly, I can do this, but I still need the VFD unit? In other words, I still need to run wires to the VFD unit, then run wires from the VFD to the control box? So I'd have two boxes, right? Am I understanding correctly?

For RPM, I thought I might attach something to the underside of the mill head near the spindle so I get the actual RPM of the spindle and not the motor.

Here's a motor plate picture:

The shaft is 24mm. Not sure of length; I didn't take the pulley off. Seems like 1.5 to 2.5" would suffice.

Here's how it's mounted:


I'm still looking thru all the other posts, but want to say thanks for all the responses.