alcazar

iTrader: (2)

Looking at buying a larger (than I already have) lathe.

The one I have my eye on is 3-phase.
I can replace the motor with a new one, 1hp, 0.75kW, for £245. That's the same size as the one fitted.
Or I can get an inverter package?

What do any knowledgeable persons recommend?

ditchmyster

iTrader: (7)

Pm JGlanzaV he's your man.

JGlanzaV

iTrader: (3)

Thanks.



As requested -

https://www.scoobynet.com/952187-my-...c-scoob-5.html

In my honest opinion, swap the motors.... The inverter works (Apart from needing a degree to set the bloody thing up) But because it doesnt give "true" 3 phase power I find the motor doesnt always have the "oomph" needed under heavy load.

ALi-B

iTrader: (1)

I once had a large 100ltr compressor that was once three phase and had a single phase motor fitted. The clue was the rating plate was for 3phase but it clearly had a 1 phase motor and starter fitted....not enough wires

I didn't do the swap (second hand), and it looked like a cheap Chinese universal motor, but it worked so it proves it can be done. Although the starter was a bit temperamental in getting the thing going first thing on a cold day and tripping out the overload - would need two or three attempts to get it going, but once running it would start/stop fine for the rest of the day. May have been the starter, or the motor didn't quite have enough oomph when operated with a starter. I never did try by passing the starter wiring it directly so it would have full current on start-up - would probably blow the breaker or slip the belt.

I assume the lathe would have variable gearing via the moving the belt to different pulleys. So the start-up torque could be reduced if there were ever a issue; I don't think there many instances you'd run a lathe's belt gearing at max speed other than to get a job done quicker.

neil-h

Any particular reason you're looking at a 3 phase motor? The spec you gave isn't a particular big one, so you should be able to get a single phase one that's up to it.

alcazar

iTrader: (2)

Neil: it comes with a 3-phase motor.
The lathes were made between 1930 or so and around 1978, they could be specced with single, or 3-phase motors, for home use or light industrial.

The 3-phase ones go FAR cheaper, which is one reason for looking at this one.

I keep missing out...every time I decide it will sell for a lot, and DON'T bid, it goes for sub £500.
If I decide I'm going to bid...often even before I will, it rises to £1000+

Yet the lathes are, to all intents and purposes, equal.

JGlanzaV

iTrader: (3)

What will you be "lathing" with it? If variable speed control is important go for an inverter, if it is not important then change the motor.

You will get better performance out of the motor by fitting a single phase one.

The controls and wiring side of it are very easy to modify from 3ph to 1ph

ALi-B

iTrader: (1)

Yeah, 3phase stuff is always cheaper and it stops most of the garden shed DIY-ers in their tracks.

I've done clear-out work in factories/machine shops that were being demolished and had loads of workshop equipment that was being scrapped at my disposal - I could have took it for free there and then if I turned up with a trailer to load it on. And I'd have had the lot for myself if I had the space...and a three phase supply LOL

alcazar

iTrader: (2)

Mostly brass, and some steel parts for model railway locos in 7mm:1foot scale, (1:43.5), but also some parts for mountain bikes etc, maybe some tooling to use on the lathe, like a rear tool post.

I already own an EMCO Compact 5, but it's not particularly good on steel. I think there might be some wear in it somewhere, but don't know enough about lathes to know where.
Plus the new lathe has LOADS of followers, so is easier to overhaul, mend, and parts etc are easy to obtain.

JGlanzaV

iTrader: (3)

Well those are you options, if you need power convert to single phase, if you need controlability and not the raw torque then go for the inverter....

I can supply the ABB inverters at a pretty damn good price. Definitely do not go for a cheapy chinese one as they provide less power too.

I am using my inverter on my 3tonne 2post lift and it works perfectly, although it won't start very well from a mid position (high loads) but will run up and down from the top and bottom with ease.

If you need any advice just drop me a message and I'll help you out. Much the same if you want an inverter I can get a price for you.

Machine mart seem to be the cheapest for motors

alcazar

iTrader: (2)

Thanks.

Lost that one too...........

JGlanzaV

iTrader: (3)

The joys of online auctions....

ALi-B

iTrader: (1)

Auction sniper?

Usually the case

alcazar

iTrader: (2)

Nope....my own fault.
came down, looked at my watch, wife asked me to start veg prep for tea, looked again and it was five minutes after the auction end.
And yes, it went for sub £500....

ditchmyster

iTrader: (7)

There's your problem, you need to get a new wife.

JGlanzaV

iTrader: (3)

LOL!

I would download an auction sniper, they are brilliant, tap in your max bid and forget about it. It will bid in the last second of the auction and only bid enough to win

No more missed auctions!

alcazar

iTrader: (2)

I'll do that.

My problem with it at the moment is finding one to bid on.
Every time I think I've found one, (Decent, but needs some work), EVERY bugger bids on it.

Every time I find one I reckon will go for over a grand, it goes for under £500......
I can't win.

I had a reply from an ebay inverter seller, told me to check the motor plate for reference to 220/240V. If that's there, I can just use an inverter, if not, it's a new motor.
Is that right?

JGlanzaV

iTrader: (3)

You can use an inverter on any 3phase motor, wether it is 415 or 230, it works on the phase lag which you don't get with single phase 230. An inverter will give you a 3ph 230v suuply.

I am running my inverter on a normal 415v motor. You need to run the motor in Delta configuartion for the inverter.

Some 3ph motors are "dual wound" and can be used on 230 1ph or 415v 3ph, you might find this is the case if they fitted the equipment with both types as it would save on the cost of 2 different types of motor.

Until you actually purchase one and can get a look at the wiring it is all speculation as to what type of supply and kit to buy as there are so many variables etc. The only advice I can give is get the one you want, check you can match it to an inverter or motor and there will be a way of making it work.

I would also advise the ABB inverters or Siemens, there isn't anything better out there and it is worth paying the extra. I run all my controls from my inverter for up/down, limit switches etc.... So the wiring is all in one tidy little box which can be mounted anywhere

ditchmyster

iTrader: (7)

See I told you he was your man.

alcazar

iTrader: (2)

Thanks for the help, to all who have posted.