3 phase equipment.

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Discussion

King Herald

Original Poster:

23,501 posts

215 months

Sunday 7th January 2018
quotequote all
I’m looking at buying a lathe, for my home workshop. The one I have my eye on is unfortunately 3 phase, whereas I have normal household supply to the garage.

What are my options? Is there a simple converter that can be used? Can the motor be converted? Would it be easy or economically viable to change it to a single phase motor?

wolfracesonic

6,940 posts

126 months

Sunday 7th January 2018
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Inverter is what you need to be Googling; check this guy out, Canadian but probably in a similar pickle to you re. 3 phase, funny as fk as well Ave's 3 phase tutorial He also has a vid somewhere about using a variable speed drive to reduce chatter on the lathe by slightly altering the speed up and down to prevent resonances building up.

cashmax

1,099 posts

239 months

Sunday 7th January 2018
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I bought a simple convertor on ebay for £50 years ago that worked perfectly for me.

King Herald

Original Poster:

23,501 posts

215 months

Sunday 7th January 2018
quotequote all
wolfracesonic said:
Inverter is what you need to be Googling; check this guy out, Canadian but probably in a similar pickle to you re. 3 phase, funny as fk as well Ave's 3 phase tutorial He also has a vid somewhere about using a variable speed drive to reduce chatter on the lathe by slightly altering the speed up and down to prevent resonances building up.
I’ll check out the video.

I did mentioned ‘inverter’ to the guy selling the lathe, but he told me it was actually called a ‘convertor’, which threw me on the Google front. scratchchin

wolfracesonic

6,940 posts

126 months

Sunday 7th January 2018
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Link to vid about reducing chatter Reducing lathe chatter I know sweet FA about machining but it even made sense to me!

jason61c

5,978 posts

173 months

Sunday 7th January 2018
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get yourself a rotary phase converter, then you can run the machine as intended.

I run a 4 post lift, milling machine and lathe on one at home.

Buzz84

1,138 posts

148 months

Sunday 7th January 2018
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It would be possible to replace the motor with a correctly specced single phase one. You could also convert the existing motor to single phase. (Almost anything is possible with the right knowledge, time and money!)

But both options would be a bit of a PITA requiring calculations and modification work.

A single phase to three phase inverter would be the best and easiest option. Plus think of all the other three phase machinery you could get to run on it!

Edited by Buzz84 on Sunday 7th January 12:21

King Herald

Original Poster:

23,501 posts

215 months

Sunday 7th January 2018
quotequote all
wolfracesonic said:
Inverter is what you need to be Googling; check this guy out, Canadian but probably in a similar pickle to you re. 3 phase, funny as fk as well Ave's 3 phase tutorial
Well that made my brain hurt. Not as simple as I expected.

The one the lathe vendor has is a good 18” long, big box, not a neat little device like the video shows.

jason61c said:
get yourself a rotary phase converter, then you can run the machine as intended.

I run a 4 post lift, milling machine and lathe on one at home.
What sort of size or rating would one need for a lathe, 8” chuck? Not a home hobby lathe, but a proper industrial small lathe. Not sure the wattage of the motor.

Buzz84 said:
A single phase to three phase inverter would be the best and easiest option. Plus think of all the other three phase machinery you could get to run on it.
Thanks what I was thinking too. I also want to buy a decent sized Mig welder at some stage. Three phase gives better options.

Condi

17,085 posts

170 months

Sunday 7th January 2018
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Is your 13 amp extension lead, or 20 amp ring, powerful enough to run it? Even if the Mrs puts the toaster and kettle on in the house?

King Herald

Original Poster:

23,501 posts

215 months

Sunday 7th January 2018
quotequote all
The breaker box in the garage has a 64 amp main breaker, a couple of 32amp and some smaller ones. It was wired up professionally, SWA cable to the house etc.

jason61c

5,978 posts

173 months

Sunday 7th January 2018
quotequote all
King Herald said:
Thanks what I was thinking too. I also want to buy a decent sized Mig welder at some stage. Three phase gives better options.
it'll say what size/hp the motor is, get a transwave one to suit.

Really is one of the most useful things I've bought. it also allows all the 12v/24v wiring on stuff to work also. you can save a fortune on buying equipment also.

I bought a 7.5hp one of these

https://www.ebay.co.uk/itm/TRANSWAVE-Rotary-Conver...

used, cost me £400.

King Herald

Original Poster:

23,501 posts

215 months

Sunday 7th January 2018
quotequote all
Sounds good. Don’t really want to spend the £700 that one is selling for, as I don’t plan to spend much more than that on the lathe itself..... boxedin

I do believe 3 phase is more efficient too, so won’t cost any more to run despite giving greater power?

S6PNJ

5,157 posts

280 months

Sunday 7th January 2018
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One other thing to consider - from my recollection of rotary converters in an aircraft hanger (for aircraft voltages, not 'industrial' 3-phase, they are not the quietest of beasts!

When my father was renting space in someone else's unit, he had a capacitive 3 phase converter which could do up to 10HP in small to large steps (ie multiple switches, switching in 0.5, 1, 2, 3, 4 or whatever HP steps) so if you wanted 2.5HP, you'd switch on the 0.5 and 2HP switches. Don't know what the name is of them but someone here might, then it's a case of Googling to get costs etc.

jason61c

5,978 posts

173 months

Sunday 7th January 2018
quotequote all
King Herald said:
Sounds good. Don’t really want to spend the £700 that one is selling for, as I don’t plan to spend much more than that on the lathe itself..... boxedin

I do believe 3 phase is more efficient too, so won’t cost any more to run despite giving greater power?
A static is much cheaper

https://www.ebay.co.uk/itm/TRANSWAVE-Static-Conver...

Super Slo Mo

5,368 posts

197 months

Sunday 7th January 2018
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There are two standard voltages for 3 phase. The usual one is 415 volts, but there’s also a 220volt standard which I believe stems from the days when some of the continent had a 110v single phase supply.

The motor on your lathe will be able to be wired for either voltage, there’s usually a removable panel on the motor with the two wiring standards (called Star and Delta) shown as diagrams on the inside.

It’s a simple process to require the motor for 220 volt 3 phase then a cheap single to three phase converter will work.

There is a snag, and it’s one I haven’t yet figured out. My lathe and drill press have contactors to manage the on/off and reverse processes, these take 240 volt (1 of the 415 phases) as the switching voltage, but they don’t work with 110 volts (1 phase of the 220 volt 3 phase).

It has to be possible to get the contactors to work, although I believe the simplest way to get it working is to just bypass the contactors and use the 3 phase converter to manage the switching process.

King Herald

Original Poster:

23,501 posts

215 months

Sunday 7th January 2018
quotequote all
I’ve heard of that before, using the converter to actually turn the motor on and off.

Unfortunately the lathe I thought was going to be mine has reached my financial limit, with 5 days still to go on the auction..... frown

Time will tell, I shall see how it goes then whack my max bid in seconds before the end.

jason61c

5,978 posts

173 months

Sunday 7th January 2018
quotequote all
what lathe? Pop a link up smile

King Herald

Original Poster:

23,501 posts

215 months

Sunday 7th January 2018
quotequote all
No, someone here might out bid me. tongue out

minivanman

262 posts

189 months

Monday 8th January 2018
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I've used a digital inverter to power my woodturning lathe, lots of info online and gives you variable speed. Just don't get a bosch rexroth one, its crap!

alabbasi

2,469 posts

86 months

Monday 8th January 2018
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There are two types of inverters , the simple capacitor type and the rotary phase which is has a motor attached to it. I bought the simple type to run an old 4 post lift and it sucked.In hindsight, it was too much hassle to deal with and i ended up selling the lift.

If you don't have 3 phase running to the house, I'd try to find a single phase lathe. It's a lot more aggro than you think.