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Iraiam
02-16-2011, 09:56 PM
I'm in the process of upgrading my Asian lathe to 3 phase with a VFD, The 15 HP RPC is ready and I have a VFD bought and tested, now all I need is a motor for the lathe that will sort of fit.

I think the Chinese motors have NON NEMA mounting dimensions on them, I was unable to cross reference the mounting dimensions with any NEMA motor mount, Oh well, I'll just make an adapter.

I am also seriously considering putting the mini-mill on the standalone milling table that Little Machine Shop sells, as I use the mill more and more all the time, I am short on space though.:mad:

http://i1192.photobucket.com/albums/aa329/iraiam/100_2325.jpg

Andrew_D
02-16-2011, 10:02 PM
Why are you using a rotary phase converter and a VFD? Why not a VFD that takes single-phase in and outputs 3-phase? Or maybe you already had the VFD for 3-phase in and 3-phase out?

Just curious...

Andrew

Deja Vu
02-16-2011, 10:08 PM
I hope you record the upgrade. I'll be watching for your update post.

Iraiam
02-17-2011, 03:22 AM
Why are you using a rotary phase converter and a VFD? Why not a VFD that takes single-phase in and outputs 3-phase? Or maybe you already had the VFD for 3-phase in and 3-phase out?

Just curious...

Andrew

I have had the RPC for about 15 years, and the price was right on the VFD with 3 phase input.

macona
02-17-2011, 03:45 AM
Very few VFDs actually require 3 phase input. Even if they say 3 phase most of the time they will run on single phase. It seems only the massive ones have phase checking.

Iraiam
02-17-2011, 09:39 AM
Very few VFDs actually require 3 phase input. Even if they say 3 phase most of the time they will run on single phase. It seems only the massive ones have phase checking.

Interesting, I never heard that or tried it before, I guess because I usually always had 3 phase power available.

yul m6
02-17-2011, 09:43 AM
Outside North America, motors are metric and are built to IEC frames. I am presently looking to upgrade my chinese mill and lathe to 3 phase and vfd. I Googled "iec motor frame chart" to find my motors. And there are a few internet dealers selling metric motors in the US at reasonable prices.

Iraiam
02-17-2011, 10:20 AM
Thanks, I'll check it out, It would be nice to get a motor that would just bolt on.

mbensema
02-17-2011, 05:43 PM
This chart has the dimensions you need to determine which frame you need to bolt in. The shafts might be different on the Grizzly motor, I had a Delta drill press with a NEMA frame motor, but metric shaft, so that might cause problems with pulleys if you have a customized motor.

http://baldor.com/pdf/501_Catalog/BackCover.pdf

IEC motors are not that difficult to find, Factorymation carries WEG and Brook Crompton.

http://www.factorymation.com/s.nl/sc.2/category.84662/.f

RobbieKnobbie
02-17-2011, 07:35 PM
Very few VFDs actually require 3 phase input. Even if they say 3 phase most of the time they will run on single phase. It seems only the massive ones have phase checking.


Very true. In my shop I have two 3in/3out vfd's running. I derated them a little, IIRC one is 2HP the other 1.5 and they're a 1.5hp and 1hp motors respectively. Both are older models and were gotten a ways back because 'the price was right' (which is to say FREE!)

If you can stomach my 2 cents, I'd say forget the phase converter and just use your VFD setup. The hardcore electricians may differ, but I don't think the phase converter is adding anything to the mix but another layer of inefficiency.

Graingers has a full line of metric motors, though I can't speak to their prices.

RobbieKnobbie
02-17-2011, 07:54 PM
Forgive my prying, but is that a Starrett magnetic indicator holder with a GREEN label??? (on the left of your picture there by the red starrett box)

Just wondering, on account of I've never seen them anything but red.

Iraiam
02-17-2011, 10:03 PM
Forgive my prying, but is that a Starrett magnetic indicator holder with a GREEN label??? (on the left of your picture there by the red starrett box)

Just wondering, on account of I've never seen them anything but red.

No it's a GEM brand magnetic base, I think it came from McMaster-Carr. The Starrett box is just a holder for a bunch of lathe bits. My shop (dungeon) was pretty messy when that picture was taken.

I'll try my VFD on single phase, My RPC has been set up for years so using 3 phase power if needed won't be any problem, I used 3 phase regularly for testing/running some vacuum pumps after rebuilding them, not much anymore but I still use it now and then.

Mcgyver
02-17-2011, 11:21 PM
Why are you using a rotary phase converter and a VFD? Why not a VFD that takes single-phase in and outputs 3-phase? Or maybe you already had the VFD for 3-phase in and 3-phase out?

Just curious...

Andrew

just because you have three phase doesn't mean you don't ever need variable speed....how else would you get it?.....and running the VFD on 3 phase means you don't have to down rate things, no need for a bigger vfd than the motor, ie a 5hp vfd works on a 5hp motor. Starts to make a cost difference, ie 5 vs 7.5 hp. I'm looking at it for a 10ee where speed control has to be done at the motor for example....I've got a 600v 3 phase motor and 600 3ph power (RPC -> transformer) but no 600 single phase so it might make sense in that case to put 600 3ph into the VFD

mitsue
02-18-2011, 09:02 AM
I am running a 3hp 3phase lathe from a Mitsubishi FR-S500 VFD on single phase 240 volt supply. I believe the vfd is good for a 5 hp on 3 phase, (3.7kw= ?hp). I was instructed to hook each incoming 120v line to L1 and L2 connections and to install a jumper from L2 to L3 so the inverter shares the load internally. It is a gearbox lathe so I change gears for power and run the vfd between 30-90 HZ to control speed. It runs very well. To install it I ran the incomming power to it and the 240/24volt control transformer. My machine used two contactors for forward and reverse to the motor. I connected the motor power direct to the vfd output and ran the control logic inputs thru the contactors to use the apron spindle start lever and foot brake switch. It operated from all the factory controls this way.
just my 2 cents,
Darcy

Iraiam
03-05-2011, 10:38 PM
My VFD is an ABB brand, the manual specifically states not to use a single phase input with it. Oh well, no problem.

I got the large mini milling table from LMS, I was a little worried at first. I trammed it in and the angle gauge was off almost a full graduation, I erased the original mark and made a new one with a razor blade, I had to shim it .001" front to back. Now when I tram it on with a piece of 8X8 glass on the table I can rotate the spindle 360 degrees and see no movement on the indicator.

http://i1192.photobucket.com/albums/aa329/iraiam/100_2336.jpg

I wound up buying a NEMA frame 3 phase motor for my lathe because the price was right. It won't be a problem to make an adapter plate to mount the new motor.

I also found a 3 phase load center at the Habitat for Humanity store yesterday for $25, will work out nicely since I need multiple 3 phase circuits now.

With the mill removed from the lathe, I see there is a nice flat surface behind the bed to bolt something to. Hmmmmm?

http://i1192.photobucket.com/albums/aa329/iraiam/100_2337.jpg

Iraiam
03-11-2011, 10:08 AM
It appears that I will no longer need the back gear on my lathe, I have tested the VFD and Motor from 5 HZ to 120 HZ with no problems.

The best part is that even at 5 HZ the 3 phase motor has far better torque than the original 110v does at full speed. The original motor also has problems getting up to full speed when the belts are set to max spindle speed (2400 rpm), which I use quite often turning small parts with carbide tooling.

Andrew_D
03-12-2011, 01:01 PM
just because you have three phase doesn't mean you don't ever need variable speed....how else would you get it?.....

Since he had a 3-phase converter I assumed he was running the whole thing off of single phase originally (single phase lines -> 3-phase converter -> VFD -> motor). As mentioned, it would be simpler to run a single-in 3-out VFD, although the OP stated he already had the converter sitting there....

Andrew

Iraiam
04-16-2011, 08:00 PM
Well, I got it done for the most part, and I am very happy with the results. I still need a few things for it, The disconnect for the control cabinet came in wrong so I'm using the breaker in the 3~ load center right now. I went ahead and kept the back gear, this thing has way more power and torque than the puny 110v motor did, much more usable!

The panel has most of what I want, I left room for a tachometer later. the knob is the speed adjustment, the top toggle switch is the accel/decel ramp selection (low speed threading brake), the tiny red button is stop, the big red button is E-stop with a lock, the black button is start, the lower right toggle selects direction.
http://i1192.photobucket.com/albums/aa329/iraiam/100_2341.jpg

The small electrical box contains the VFD and wiring, I mounted the VFD on a hinge so I could fold it in and out of the box.

http://i1192.photobucket.com/albums/aa329/iraiam/100_2340.jpg

http://i1192.photobucket.com/albums/aa329/iraiam/100_2342.jpg

http://i1192.photobucket.com/albums/aa329/iraiam/100_2343.jpg