EMCO FB2 vertical Milling Machine

I have recently aquired one of these and am faced with a similar problem to several others who have asked for advice on this site in that it has a three-phase motor & I have a single-phase supply. Unfortunately, the motor is not dual wound, only 400-440v, and it has been suggested that I opt for a new dual-wound 3-phase motor & an Inverter.

I am, therefore, faced with having to remove the old motor from the machine, and swap any attachments to the new motor. The exploded view in the manual indicates various items in the drive train: a pinion, flywheel, adaptor and worm etc, but it is not obvious how these components interconnect.

My query is: is there anyone out there who is familiar with these machines and who can advise me of any pitfalls that I need to avoid during this operation? as I don't want to damage my new machine.

Also, does anyone know if spare parts are available for the FB2? an internet search has so far proved fruitless.

Why not just buy 240v to 415v 3 phase converter and not bother with the agro of changing the motor, may even be a lower cost option.

Bob

If you have ever used one of these, changing to a new motor is by far the better option in the long run. In my opinion.

graham.

Alastair,

'Dual wound' is a misleading expression. The windings are exactly the same on 440V and 240V motors, they are just connected differently. Single voltage ones just don't have an easy facility for swapping over connections to change voltage, they are 'hard wired'.

Take the motor to a local rewind place, they will take a look at it and may be able to dig out the star point and convert it to 240V for you for a fraction of the cost of a new motor.

You then use the savings to buy a better inverter

Neil

Graham,

I'm not talking rotary converter I'm talking a similar bit of kit as those used to power 3 phase motors at 240v the difference being the voltage is boosted to 415 volts **LINK** . So what is the problem with these?

Bob

I am pretty sure the motor on the FB2 is similar to the previous Emco mill (which is what I have) and is not replaceable by anything other than the Emco motor.

The motor has an extended shaft with keyway/splines and forms part of the gearbox so another motor would need a substantial amount of engineering to make it suitable. That, and the fact that original motors are not available (or extremely! expensive) means it is best to retain the existing motor. If it were my machine I don't think I would get the motor rewound but I would probably use a 240 to 440 V transformer feeding a VFD.

As Neil mentions there is a possibility that the internal connections of the existing motor windings might be amenable to being modified to delta configuration. Because of the 'value' of the motor do your best to find someone or a company that is knowledgeable and competent.

Whether 440 or 240 putting a VFD on the machine is the best thing to do from a usability point of view.

Ian P

May be worth asking on teh Emco Yahoo group, although its mostly lateh based there are a number of members who have the milling heads on teh back of their lathes which are basically FB-2 machines.

**LINK**

For spares you should be able to get certain ones from Pro Machine

I use a 240 - 415,single to 3 phase inverter on my student and XYZ bridgeport clone... was not cheap but certainly better than replacing both of the motors. Bought it from Drives Direct at Nottingham, guy there was very helpful, no connection other than a happy customer.

On the XYZ i dug into the control panel a bit to find 240 in -> 110v Single phase windings on the transformer for the X axis feed motor....

Ian P is correct. FB2 is the "Millerised" version of the 6speed Green milling attachment from the later Maximat V10P lathe and yes, the motor is a pain in its unique construction for Emco. Possibly Wein? Circuit in manual always causes question "Is the motor the same for 3phase and single phase" For both versions, there are three coils, one wired as three phase and other shows a capacitor wired in.

The "Green" motor was preferential to the earlier "Blue" one fitted to the 4 speed head, same with Lathe drive motor. Worth asking on the Yahoo "Emco" site.

Regards Ian.

From memory - I've sold my FB2 - the motor was made by Bauknecht, makers of washing machines & other kitchen appliances. See the similarity to machine tools?

Dave
The Emerald Isle

Thank you to everyone for your helpful responses, I've obviously got some serious thinking to do

I've fitted a 4 pole compact frame 0.55kW motor and 240V Omron inverter to my FB-2 head,

https://www.dropbox.com/s/wpthacbocfp2xx3/PICT1546.JPG?dl=0

The standard motor shaft was a size smaller so I stripped the new motor and re-machined the shaft nose in the lathe.

The flywheel, primary drive gear and gearbox oil lift screw all attach to the shaft via the internal thread in the motor shaft nose.

The plastic gearbox oil lift screw shaft is easily broken if the motor isn't carefully lifted out vertically but it's also easily repaired with a section of speedo cable inner and epoxy if you do break it and once you repair it this way it's no longer sensitive to handling or alignment.

Measure your proposed motor carefully, even the compact frame motor I used required a spacer ring to move the mill head 8mm further out from the column, I could have removed a couple of fins and slotted the fan cover but I fancied the additional 8mm throat.

- Nick

Edited By Nick Hulme on 29/04/2015 10:31:38

Edited By Nick Hulme on 29/04/2015 10:32:32

Edited By Nick Hulme on 29/04/2015 10:32:50

That a neat mod Nick.

I have the earlier 4 speed version of the mill and the motor shaft on that is a one piece construction. Is the two part design (screwed together) standard on the FB2 or is that how you did the conversion?

I dont think I would have used a spacer ring. Its hard enough to keep the head from swivelling in normal use without introducing a second face joint.

Ian P

Just noticed this thread, I converted an Emco FB2 from 3 phase to single phase about 20 years ago using information given in the book "Electric motors" by Jim Cox ( workshop practice series No. 16 ). I had to dig inside the motor to find the star point (bit of a pain as I recall, but worth it ) and then add a capacitor to the wiring. It's all explained in the book. I used this set up for more than ten years without a problem and the whole conversion only cost a few pounds for the capacitor.

The motor could not be replaced easily as it is an integral part of the design, so I would not go down that route if I were you.

Doug

You can run a 400v 3 phase motor off a VFD's 240 3 phase output, but set to 29hz. You lose a third of the RPM. The clever electrical people on here will explain better than I, but the idea, which came from this forum, worked for me.

The FB-2 motor is bolted to the top cover of the gearbox, it's a small diameter motor frame for it's power output but that's all that's wierd about it, it's spindle has a standard nose for it's shaft size, I just machined my new motor's spindle nose to match in size and screwed the parts on.
When I added the spacer ring I needed longer clamping bolts so I ordered good quality high tensile bolts, machined the heads to fit the circular groove in the column section, trammed the head and torqued them up good and proper. The spacer plate is a stepped ring to mate exactly with the front & rear sections of the head, the rear joint was a firm fit and is bonded in place , there's no sign of any movement at all.

If you were to go with slightly less power than I did then frame size wouldn't be an issue and the motor could easily be replaced. After all, it's just a motor and "Where There's An Engineer There's A Way", conversely I suppose "Where There's No Engineer There's No Way"

- Nick

There must be different versions of the FB2, my one had a specially shaped motor casing which was unique and could not be replaced by an off the shelf motor.

Doug

Emco FB-2 -

http://static.webshopapp.com/shops/036767/files/015177803/emco-fb2-milling-head-attachment.jpg

Remove the 4 top cover fasteners, remove the bolts on the inside which retain the motor and then drill the right holes to fit a flange mount alternative or even drill & tap a non flange mount front cover and bolt that on.

The FB-2 is a 6 speed head, the earlier 4 speed milling heads (MM1?) appear to have the motor front/gearbox top as an integrated casting -

http://www.lathes.co.uk/emcomiller/

I'm only referring to the FB-2.

- Nick

Alastair,

Have sent you a PM about your 3-phase motor.

Phil

Well done Doug, sounds like a good option to me!