Running Bigger Lathe 3 Phase on 16 amp Single phase ??

[Hybrid_From_Hell]

Hi those that know !

I curently have a Nice Boxford SP Lathe, but I defo wnat something bigger

So, this thread is posing 2 Questions.

1. The lathe itself.

I am familiar with the Harrision M300 Short Bed lathe, this is prob top of my list

closely followed by maybe a Colchester student, but Q is maybe what others should I consider ?

What are the variations of the Student ?, and whats a Major and Chipmaser vs Student ?

OK

The 2nd Q is powring

I have a 16 amp single phase supply only

I have been looking for a single phase bigger lathe now for some time, they are both

rare, seem to go for a premium and often not everything works due to conversion badly done !

I really know very little about running 3 phase on single, I know little about convertors, understand there are digital and rotary and I don't know what

this means, so educte me !

What sort of HP is a M300 or Colchester and how big a convertor do I need ?

Help !

Nige

[vulcan bomber]

Personally i'd go for any Harrison lathe over a Colchester..

We, up until recently had a Harrison M390 and an M400 at work (both probably a bit big for your garage). And they both took a hammering all day everyday and yet were also very precise, very sturdy and very well built, to the point I wish we still had them.

We also had a Colchester master that needed head stock bearings alot sooner than it should of so it was scrapped and the Colchester Triumph 2000 we have to replace the harrisons is just carp and wants scrapping imho.

I used a Harrison M300 while I was at college and it was an utter joy to work on as well.

Myford produced some very nice lathes along with Denford and as you mensioned so do Boxford.

[Somethingwitty]

Nige,

I last used a lathe 10 years ago at uni and nor have I played with three phase - however I have been looking at 3 ph for various workshop things (inc a lathe) I have some electrical understanding - probably enough to be dangerous, particularly to a third party! With that in mind, here is a rough understanding:

Your options are:

1. Get a 3ph supply rigged to the workshop (and quite possibly get greater capacity at the same time) - prices will vary, you can't take the cabling with you if you move either!

2. Rotary converter - these can be bought or made, the rotary bit is a slave motor of at least the same capacity as your lathe motor that is employed to 'make' a third phase (that may not be the best or most acurate description but essentially you are driving two motors instead of one with a box of capacitors etc to assist.) You have no control over the frequency thus the motor will run at it's design speed (dependent on the number of poles it has, fixed by design)

3. Digital inverter a. 240v 1ph -> 415v 3ph

b. 240v 1ph -> 240v 3ph

Of the option (3) unsurprisingly (b) is cheaper... but can you use it? It depends on the motor - most more modern motors are 'dual voltage' and can be wired (by bars in a connection box) either for 240 3ph or 415v 3ph - I don't belive there is any significant disadvantage with 240 but it does enable the use of a 'single stage' inverter thus lowering price. (the connections are refered to as 'Delta' and 'Star' - seek clarification as to which is which!)

The great advantages of a Digital Inverter are:

- Can take it with you when you move
- If a Variable Frequency Drive (VFD) you can infintely vary the motor speed (reduces the gear / belt changing to probably a hi / lo functionality)
- Many provide electrical braking
- can make pre-set ramp up / down for more controlled start / stop - kinder to you and machine
- can make preset max speed limit (essential you do this with VFD - you could easily exceed design speed of motor)

There are probably more but I forget them! Prices are not astronomical (but increase significantly around 4-5 HP) - Invertek 1.5kw / 2 HP IP66 is £267 (probably plus VAT....) but thats the waterproof one, lower IP ratings are cheaper. Why have I mentioned IP rating? It's something I'd not considered but a workshop can be a pretty aggressive environment for electronics - grinding dust, paint spray etc precipitating out or being sucked in - worth considering how you will protect your investment. Beware of 'cabinet mounting' - there are specific ventilation requirments to meet and whilst I've not got my head around it I've seen 11CFM mentioned where a filtered air supply is needed!

For more info on inverter drives I suggest the following:

www.inverterdrive.com/file/Invertek-Drives-Optidrive-E2-Manual - This will give you an idea of a model range's capability, the source website has more models and prices

From that link above for example I can tell you that a 0.75Kw / 1HP motor will reqire 12.5A nominal / 16A fused supply (1.5Kw / 2HP requires 14.8A nominal / 25A fused) - again seek professional guidance but you may need a beefier supply (but this ought to be just a bigger / second cable from your consumer unit rather than a more expensive laying of 2 more phases from wherever they might be available beyond the house).

For more on 3 ph motors: Link

And real geekyness on Inverter drives (in industrial depth considering significant refinements not a concern for us... but includes points on motor cooling for example, i.e. motor driven well below design speed for long periods may need an independent fan): Link - part of site above

and a more practical look at 3ph for lathes (and far more): Lathes.co.uk

Finally, recommend looking at: Model Engineer and similar sites - lets face it, most of them have a lathe, most of us sadly do not!

Bit long but hope thats useful - Jim

[Somethingwitty]

Further to my last:

Harrison info

May not be fully up to date but talks of a 3HP 3ph motor as standard (you would need more than 16A supply) but also mentions a weaker 1ph motor (with reduced top speed). Having looked a the photos it looks very much like what I used at uni - and that was excellent (in my humble capacity as a machining biff).

[Hybrid_From_Hell]

^^

Thats useful info from all so far

Thank you - keep the info coming

This looks rather spiffo .......unsure if this is going rate ?...seems a bit pricey ?

http://www.gandmtools.co.uk/cat_leaf.php?id=9389

[CwazyWabbit]

Seems a bit pricey, a 3 phase one sold on ebay for 1500 recently http://www.ebay.co.uk/itm/130862468879

[Cynic-al]

We have a Colchester triumph 2000 and every mould tool maker has one stuck in the corner, it does its job. We got it from an auction with dro, 3&4 jaw chuck, a few quick change tool posts, chuck roller bearing guide for the tail stock and A selection of tooling for £600 so there are bargains to be had.

The Harrison's we used at college did their job too! In fact I'd almost say I preferred them, but maybe that's just nostalgia!

With regard to getting a 3phase supply, although its the best solution it's pretty expensive, a friend did it and it pricked the interest of the council who decided he was running a business, needed planning for chang eof use of premesis and should pay business rates. :/

I believe the digital inverters are more efficient, the soft start isn't so useful on a lathe as you tend to engage the load mechanically and use the on off on the machine but it is kinder on the supply and should help if it is a smaller supply.

[vulcan bomber]

^^

Thats useful info from all so far

Thank you - keep the info coming

This looks rather spiffo .......unsure if this is going rate ?...seems a bit pricey ?

http://www.gandmtools.co.uk/cat_leaf.php?id=9389

Thats a training school lathe, the motor wont handle much in the way of a roughing cut and drilling big holes will take alot of time. Not only that but 1250 RPM on a Lathe that size is very very slow. My Lathe at work will throw around 18 inches and often, 1500 RPM isnt fast enough.

[TheRecklessEngineer]

+1 for invertek.

Just ordererd a 36kw version for a pump at work.

[vulcan bomber]

How about this one? Its nothing to do with me.

http://www.ebay.co.uk/itm/HARRISON-M300-LATHE-PACKAGE-WITH-TRANSWAVE-CONVERTER-AND-DRO-/330899949955?pt=UK_Home_Garden_PowerTools_SM&hash=item4d0b2c8983

[mickeyw]

My Student 1800 you looked at on Friday has a 3HP motor. I would imagine the Harrison M300 is similar to that. My converter is 4HP.

Never used a Harrison, but never had a problem with Colchester Student or Master.

[mickeyw]

the Chipmaster is a good bit smaller than a Student, good size for your garage though

The one I used had a variable speed gearbox and gave a fair bit of trouble. When it was working it was a pretty capable machine.

[Aragorn]

3hp is only 2.2kw? It should run just fine thru a digital inverter on a 16A supply, however you might need to install a C type breaker if startup current is an issue. An inverter with soft start should cure that though.

[Astro_Al]

Nige, I have (now) a colchester triumph. I think its a good size - get 2" bar down the spindle etc. Quite a handy machine. Anyway, the guy I bought it off had put a single phase motor in, I was given the 3 phase motor that he removed when I bought it, and despite having 3 phase in the workshop I haven't needed to swap it back.

I'd seriously consider just getting a big machine and running it with whatever your maximum size single phase motor is. Easy peasy.

Al.

[mickeyw]

I'd say Nige's inventing shed is a bit too small for a Triumph or anything of that size

[Astro_Al]

Ah, well, he said he wanted bigger...

Anyway, I guess he could do the same with whatever lathe he ends up with.

Al

[sean f]

I am looking at exactly the same thing as HFH even the same options of lathes so have been following this.

Well getting a 3 phase supply is not likely to be cheap.

Just had Western Power round for a site visit and estimate, the local transformer / substation is about 40ft away from me but unfortunately on the other side of the road, estimate was £4 - 5 thousand for excavation alone to cross the road, end of a quite residential road, nothing busy and no traffic control or diverstions etc required. If I was on the other side of the road it would be a couple of thousand less but still not cheap, cabling, new meter etc would all be extra to that, for me he was quoting a price of approximately £7 - 8 thousand and that is just to run it to the boundary of my property after that it would be up to me to do the excavation etc required.

Looks like the invertor is a better idea even though they need a big ampage supply, made a few enquiries and pretty regularly being told that to run a 3 HP lathe requires a 9HP invertor to handle the start up reqirement for the motor, no expert at 3 phase power so not to sure how that works, any one got any more knowledge on that score?, as some people seem to be running an invertor rated the same as the motor?, I guess it may vary depending on if you wire the invertor direct to the motor or connect up the machine direct as it normally would be and use the machine controls to operate the motor. Sounds as if several people have already done this so any idea of the pros and cons of each system.

[mickeyw]

Well here is someone speaking from experience:

I have a 100A supply to my house, single phase.

I run a 4HP rotary converter to feed my Colchester Student (3HP). It's hooked up to the consumer unit via a 32A socket, to a 32A curve C breaker.

This may not be the most energy efficient setup, but it does work! On top speed (1800) the lathe will grumble a bit to get going, but most of my work does not happen anywhere near that speed.

I can't speak for the inverter style device.

Edit: Cabling to consumer unit is 4mm armoured cable, and includes an isolator box.

Edited April 17, 2013 by mickeyw

[CwazyWabbit]

I've run an inverter on a wood lathe spinning some quite large lumps of wood, the lathe has a 1hp motor and the inverter used was also a 1hp inverter. All the lathes wiring was re-done to work through the inverter, this allows for soft starting and controlled braking without overloading.

I know a wood lathe isn't the same as a metal lathe however the inverter has worked perfectly for me even with lumps of tree 3ft long and 12" diameter which create quite a startup load and have a substantial flywheel effect for slowing down as well. Also works well for polishing or with a wire wheel

[TheRecklessEngineer]

I think I was lucky. When I had a new supply fitted for my abode/workshop, it was £50 more expensive to get 3 phase.

[sean f]

I think I was lucky. When I had a new supply fitted for my abode/workshop, it was £50 more expensive to get 3 phase.

Most of the cost was quoted as the trenching across a public road, I suspect if anyone is getting a new supply for a new build house or workshop then the extra for the three phase would only involve a heavier 3 phase cable being laid any excavations would be the same, so as you say the extra would only really be a nominal amount and definately worth doing even if you have no immediate need for it.

I was also told if it is an overhead supply it would be cheaper, especially if no extra poles were required.

The man from Western power was quite helpfull and informative, checked my existing supply and meter, the meter is only a 80amp one so would need to be upgraded to 100amp, he belived this would be free and done by the energy supplier (I suspect free as they believe they will be selling you more power so will get the money back). If I had lived on the newer side of the estate he would have had to do some checks to see if it was possible at all as apparently that side is already close to its upper limit for capacity.

[CwazyWabbit]

These people are worth talking to about inverters http://www.lathespeedcontrol.com/

It's a company called Newton Tesla and they have been around years, I spoke to them ages ago when fitting an inverter and they were extremely helpful and answered loads of questions for me. They deal with everything from hobbyists with little 750w motors up to big businesses running motors of 400+KW !

I have nothing to do with them other than being a happy customer I was also impressed that even after purchase they continued to answer my questions and help me.

https://www.facebook.com/pages/Newton-Tesla-Electric-Drives-Ltd/205059422865706

[discomark10]

if your still stuck with this, my old man made a power supply 230v 2-phase in running a big 3-phase motor on his lathe. i could ask him for some info if you want?

[heath robinson]

Nige, look at this guy's page, and maybe drop him a line at motors@minchin.org.uk. He's the 3-phase guru that used to frequent UKWorkshop.co.uk, so maybe mention that's where you were pointed to him from. He's always been exeptionally helpful and knowledgable in the past, and single-to-three-phase shenannigans is his stock in trade.

[heath robinson]

Also, have a look at ukworkshop.co.uk, there's a ton of info on there about 3 phase motors and converters, woodworkers seem to spend more time restoring old machinery, and installing it in unsuitable places, than they do actually woodworking...

Although, like this place, their search is pants so use the google inurl:ukworkshop trick.