Converting M300 to single phase motor

[Shox Dr]

Looking to swapout the 3HP 3ph motor on my Harrison M300 lathe.

I know I'll have the strip out all the 415v kit and install 240v relays for the safety switches ect.

But... would I be better off fitting a 4HP 240v motor, instead of a for like 3HP they are only 10-15quid more?

Anything else I need to know. Besides the age old "1ph isn't as smooth as 3ph"

 

[FranV8]

How about fitting inverter drive instead? Or is it a super pokey motor?

 

[Shox Dr]

I've already got a 7.5HP Rotary. But it's noisy and vibrates. Does my head in.

A 4HP 1ph motor is only £170ish

 

[penfold]

Single phase motors vibrate too; an inverter lets you keep your nice smooth 3 phase one and gives you infinite speed variation.

 

[thinfourth]

A modern solid state inverter is the mutts nuts

I have one and it gives me huge control over the motor speed from 1hz to 80hz

 

[Shox Dr]

I know enough about the pro's and cons of rotary and VRFs I have them both.

I want to know about fitting a 1ph motor

 

[tigler]

Go for a capacitor start and capacitor run type motor. Better torque and more efficient.
Also, please excuse this comment if it's stating the obvious but make sure you get the correct motor speed, ie, there are 2 and 4 pole motors.

 

[Shox Dr]

Sorry Tigler I should have stated I was looking to replace it with a 4 pole 1400rpm cap start/run.

It must make sense to fit a 4HP rather than a 3HP, yes/no?

Any make to stay away from? or better still a recommendation of make and model/type

 

[tigler]

Well it can't be a disadvantage apart from using more power than necessary.
A CSCR motor will have enough torque to replace the 3 PH without having to go to higher power.
Personally I would always use a British or European 'MADE' motor even though they cost more. They are higher quality than Chinese stuff.

 

[hotrodder]

Dunno if it'd apply to an M300 and/or i might be talking nonsense (electricity is witchcraft) but the factory single phase (and DC) versions of my Colchester were quite different to the 3 phase models... something about single phase motor windings being delicate/weedy and not liking being switched so the on/off lever/spindle brake was swapped for a clutch and the motor was left running constantly

The Harrison at the workshop (an early 13" i think it's 3hp too) is certainly not overpowered i.e. if you're being an animal you can drag the motor down before you start getting chatter/wonky cuts. My thinking is that the OE 3hp motor is probably a 'more honest' 3hp than most modern motors, especially those bought on price.

ETA i get not liking the noise etc from a rotary converter, what's put you off VFDs?

 

[Shox Dr]

Cheers, I'll pop in to CEF, and the indy tomorrow

 

[Shox Dr]

ETA i get not liking the noise etc from a rotary converter, what's put you off VFDs?

cost

 

[hotrodder]

Gotcha but once the motor's have been rewired one vfd can be swapped between different machines. Obviously that's irrrelevant if all the usual 3 phase suspects have already been aquired and converted to single phase/are run from smaller vfd that isn't man enough for the lathe

 

[FranV8]

Just to check - you spoke about knowing about rotary and static converters, a VFD is a very different beast, overcomes a lot of the issues spoken about. Only thing I'm not sure about is the cost of a 3hp one - on the Homeworkshop site 0.75 hp's often go for a lot less than the ton (£65 to £85 if I remember correctly)

 

[Shox Dr]

Yup understand how Rotary, Static and VFDs (err not VRF) all work
Currently own a
1x 7.5HP Transwave Rotary.= runs M300
1x 230v 12A Alan Bradley VFD - runs Mill
and another 1\4hp VFD = in a box

Motor on lathe is a 3HP 3ph 230/415v

I'm like Hotrodder leccy is the work of the devil.

Cheapest 3hp VFD i can find is £260.

 

[ford34/2]

E bay item

feed back from a buyer on E bay gave a thumbs up, if you were at all interested in the E bay link recomendation, (its almost too good a deal to be true), I would check with the buyer- send him a PM. My big worry, why if this item is shipped from Portsmouth by Fedex or DHL does he charge £38

http://myworld.ebay.co.uk/graysclassics

his feedback he left is on page 43

Brilliant Price! Great service. Compact unit. Can't wait to use it. 5 stars graysclassics ( 588) 01-Aug-12 12:01
PROFESSIONAL 13A 3KW 4HP VARIABLE FREQUENCY DRIVE INVERTER 220-250V VFD m8 (#190615864317) £73.00

My only concern with a 4HP single phase motor would be what amps will it pull, doubt its a 13 amp plug job, I think it runs at 12ish amps+ the start up load.

anyway time that machine was running.

Stan

 

[Shox Dr]

My only concern with a 4HP single phase motor would be what amps will it pull, doubt its a 13 amp plug job, I think it runs at 12ish amps+ the start up load.
Stan

Thanks for the link Stan, seller looks to sell alsorts, so that might have been a one off. Also not currently listing anything on bay.

As for current draw of a 4HP, I have a 40amp Blue socket next to the lathe for other gear

 

[ford34/2]

SORRY--I`m misleading you, I was referring to a buyer who bought the same item, I thought it maybe worth a pm asking him, is it any good, the item he bought and other HP rated units are for sale::

http://www.ebay.co.uk/itm/4HP-3KW-1...al_Components_Supplies_ET&hash=item2c61974311

or item:190615864081

sorry to muck ya round,
Stan

 

[penfold]

I linked to a 3kW inverter that's listed for £110.

 

[Shox Dr]

Sorry Penfold I didn't see that. Looks like Stan and myself found the same.

I'll not bother, yellow crap, by the looks and wording. Would only buy a known brand. IMO Bradley etc