A new motor for my lathe

[JimB]

Split off from this thread:

Tesla coil progress

How is three phase different than just adding the frequency? Single phase "pulses"; the voltage drops to zero twice per AC cycle. Three phase is totally balanced, you can draw the same amount of power all the way through the AC cycle, with suitable loads. It also inherently has a rotation...

www.electro-tech-online.com

JimB said:

I have a small lathe, a Myford ML7 which is nearly as old as I am.
A year or so ago I replaced the old single phase motor with a three phase motor and three phase variable frequency drive.

Western asked:

What size is the motor Jim and what sort of VFD are you using. I'm assuming you run it off single phase still??

The new motor is rated at 0.55kW (0.75HP), compared with the original motor which was rated at 0.25HP.

The new motor:

The old motor and home made Start/Stop/Reverse controller box

The VFD is a Jaguar Cub.
It came as a bare module suitable for mounting in a control cabinet.
Rather than just having it fixed to the end of the bench and prone to invasion by swarf and spiders, I built it into an enclosure as shown here:

The extra transformer and contactor is so that I can implement some kind of emergency stop kick-bar for when things go pear shaped.
I must get on and do that, it is nearly a year since I built this thing.

Also, using an enclosure like that allows the use of reasonable terminals for the "field cables".


The overall view, this picture was taken before I fitted some cable trunking to tidy up the field cables which connect the system together, and fitted the guard back on the drive belt and countershaft pulley.

The incoming supply to all this is the normal 240v single phase domestic mains.

JimB

 

[Ian Rogers]

I need one of those.... I miss my workshop.. I have gone from... Lathe, milling machine, tap & drill, Multichuck drill bandsaw and machine saw to a single drill. I cannot modify anything...

Have you had it ages??

 

[Pommie]

At the school I work at they have just removed two myford lathes (both three phase). They are currently in an unused area but need to go. They have to go to tender, a teacher has tendered a bid of $10 for one and will probably win it!!!

Mike.

 

[Nigel Goodwin]

Your old motor looks like it came out of a VERY old washing machine

 

[JimB]

Have you had it ages??

About 21 years.

Your old motor looks like it came out of a VERY old washing machine

The old motor was made by BTH at Rugby, and was probably fitted to the lathe when it was new in about 1950.

At the school I work at they have just removed two myford lathes (both three phase). They are currently in an unused area but need to go. They have to go to tender, a teacher has tendered a bid of $10 for one and will probably win it!!!

Lucky sod!

Myford lathes of this type are an old design, some would say crude, but they are reliable and can produce good work.
In the model engineering world, some of the sceptics say that they have a cult following.


JimB

 

[picbits]

I've just acquired a nice old Atlas lathe to go with my other two lathes that I've never used ..... at some point I'll fit the three phase motor and vfd I bought for the other two .....

 

[shortbus=]

Have seen the name Myford for a long time but never saw a picture of one. It looks like a copy of a Southbend here in the states. Or maybe Southbend copied Myford. I have a Southbend 9" from back in the 1940's and the gear cover looks like they could interchange.

 

[Western]

The new motor is rated at 0.55kW (0.75HP), compared with the original motor which was rated at 0.25HP.

The incoming supply to all this is the normal 240v single phase domestic mains.

Thanks for answering those questions Jim and for the photos ... they're worth thousands of words.

And I Iove how you've gone about it. Something I can aspire to for my future lathe.

 

[Western]

At the school I work at they have just removed two myford lathes (both three phase). They are currently in an unused area but need to go. They have to go to tender, a teacher has tendered a bid of $10 for one and will probably win it!!!

If I recall correctly you're in Queensland Pommie? I'm way down in SA and have been wracking my brain to work out how I could score one of them myself.

What would they sell for normally on the open market out here in Aus?

 

[JimB]

Thanks for answering those questions Jim and for the photos ... they're worth thousands of words.

And I Iove how you've gone about it. Something I can aspire to for my future lathe.

Praise indeed, thank you.

Something else for you to think about, the control cabinet for my CNC milling machine is here:

Control panel layout

Hello all Wondering if there is a thread with suggestions on where to start with a basic control panel layout? Searching I haven't come across anything Basically the best layout for relays, power supplies etc, I haven't had the experience of doing it before but would like it to look neat and...

www.electro-tech-online.com

JimB

 

[Nigel Goodwin]

About 21 years.


The old motor was made by BTH at Rugby, and was probably fitted to the lathe when it was new in about 1950.

I imagine they provided motors to washing machine manufacturers (and everybody else) as well.

 

[Ian Rogers]

Pommie..A bit far for me to pick up...

 

[Musicmanager]

@Pommie..A bit far for me to pick up...

Nice trip though .. .. .. .. on expenses ??

 

[Nigel Goodwin]

Nice trip though .. .. .. .. on expenses ??

Makes it even more difficult though, with their incredibly sensible Covid 19 policies - although they were utterly stupid to allow the Australian Open to go ahead

 

[Pommie]

When you've got good border controls and make super stars isolate, a tennis tournament is easy.

Mike.
Not sure what the going rate is here for a myford. Will try to find out.

 

[5uco]

The lathe may well have had a 'washing machine' motor fitted.

I bought a new ML7/T ( tri-lever ) in 1971 and a motor was not included in the lathe price.
IIRC all you got was the lathe, face-plate, catch-plate, 2 centres and the change wheel set.
A few tools including that useless oil-gun.

Anything remotely useful was an extra.

Pretty sure you got no motor, no chucks, no raising-blocks, no drip-tray, no thread indicator, no lead-screw hand-wheel etc.

Now got a tooled up Super7 with a VFD and a WARCO 280V with same.

D.