Rust on New Lathe

I don't think it is remotely acceptable that a supposedly brand new product was supplied with paint and rust faults, no evidence of protective wax/grease, and traces of oil leaking. All faults point towards bad quality control, poor shipping process and storage in humid or wet conditions.

What have those conditions done to the components you cannot see - the motor, the switch-gear, the internal gears etc? And if the storage personnel and conditions were sub-standard; how else might the product have been damaged - might it have been roughly handled or otherwise abused ?

I would have absolutely refused to try to clean the rust off - it is not your problem, it is the supplier's. Sale of goods act : "product is not fit for purpose". The supplier must be given a chance to rectify the problem, either by supplying another machine or giving a full refund. I would also be asking to see the pre-delivery accuracy check report on the replacement machine, if you go down that route.

If you bought a new expensive watch, which on opening the box, had rust on the strap or the case, or a scratch on the face, you would take it straight back and demand a refund. Being engineers, we are good at - and like to solve - engineering problems, but that should not extend to correcting faults on brand new equipment.

I agree with others: that lathe does not look brand new, it has been supplied and returned already, or is damaged stock.

Edited By John Doe 2 on 10/11/2022 10:40:45

I see references to scotchbrite and have only a general idea of what is meant. "Scotch" is I believe a 3M trademark but I suspect that the term has become generic and can cover a variety of products and abrasive qualities.

I would welcome some enlightenment.

Good luck to the OP in resolving his problem.

I would not except it, you have paid for a new lathe with no damage and this one has damage. They should either take this one back and replace it with a new one in pristine condition or you should get your money back, no ifs and buts. Niko.

Warco has a good reputation. It has been around longer than many traders, including ARC. Whilst it has been taken over by a new management team, to the best of my knowledge, the original warehouse/technical staff have been retained, and the team carries on providing the same level of service they are known for. Some may approve and some may not. That is just down to personal preference and experience.

Just check the innards for any signs of rust, and if the machine works as it is supposed to, you still have a years warranty should the electrics have a non-user related issue during this period. Re-packing and sending the machine back is an option you have, but what is there to say how different the replacement will be to meet your expectations?. Remember that it is a heavy machine. Looking at what you have done based on Warco's suggestion is a great result. It does not mean that a bare surface is more prone or less prone to rust in the future.

Bare surface on every machine is prone to rust, especially in winter. Regularly wiping the bare surfaces with light grade oil keeps the rust at bay. If you fail to protect the bare surface, the humidity/moisture in the air - especially in a cold garage type environment will generate surface rust. If you stay on this forum, you will see a few posts in the coming months on surface rust, protection aids etc..

At the end of the day, you make your own decision.

Ketan at ARC

Correct!

My feeling is the lathe should be OK, because the rust is cosmetic. And given that the lathe spindle runs on sealed ball-bearings, the 'oil-leak' is probably nothing, perhaps caused by oil splashing about in the gearbox during transit.

Rust under paint gets worse once it's started, but not plain metal. It's not a disease. Lathe beds are always prone to rust and it's the owners job to control it. Much depends on how damp the workshop is and how much the temperature swings overnight. Normally, it's more than sufficient to wipe oil over the ways before and after each session, but some folk have to do more. Free-standing single skin garages and uninsulated sheds cause more trouble than a double-skinned garage that's part of the house.

Based on the limited evidence of a few photos, I see a number of posters insisting the machine is 'unfit for purpose' and war must be declared. As starting a fight is easy to recommend when one is in complete safety, I'd take the advice with a pinch of salt! The customer has to deal with the hassle, not chaps on the internet with strong opinions but no skin in the game. Beware too, that some have an agenda in which nothing but an old-school Western made lathe is any good.

My hobby lathe and mill are both Far Eastern. Neither is built to industrial standards, but both have done what I need and are still going strong after 6 years. The lathe needed minor tweaks, the mill was acceptable out-of-the-box. They're OK rather than wonderful, and it was no surprise to me that a fully accessorized hobby lathe wasn't finished to the highest possible standards when it cost less than a quarter of the price of a similar western industrial lathe with no accessories. Industrial machines are built for sustained hard work, that's rare necessary in a genteel home workshop!

There's reasonable concern that water ingress may have caused unseen damage. If the machine runs properly this is unlikely, but a compromise might be to ask for the warranty to be extended. Warco might be unwilling because the machine is already covered for a year, but it could put John's mind at rest.

Dave

No worries Steve, Weiss and their distributors have great marketing.

Hugh does your machine not have a brushless motor where as the Warco has an AC 3-phase motor and inverter. From many postings on the forum I would say a lot of people favour the inverter option over brushless and are willing to pay more for that option.

Your 135rpm minimum speed may also put people off as Warco's 30rpm would be less but clenching when threading.

Also not sure why you list it as a 250 x 750 (10x22) and you may want to alter what ctrs come with the machine as MT5 inti MT4 won't go neither will MT3 into MT2. 

Edited By JasonB on 10/11/2022 12:28:38

You have a point about the hassle, and so on...

But the condition it turned up in is just not cricket... and Warco must be well aware that if they sent something in a condition like that to a business customer there would be a very real risk of them rejecting it out of hand and refusing the pay the PO until it was sorted.

So I would absolutely think it reasonable to push for something from Warco by way of acknowledgement of the fact that they cocked up, without going overboard.

I feel like they don't have a leg to stand on here, given the inevitable compromises of buying a used lathe...

Short of happening on a Hardinge that's spent its life in a climate controlled university lab, now reselling for the mere price of a new car, or some equally infrequent and unlikely scenario... You're just not going to find a used lathe in as clean a condition as the WM250V in the pictures.

FWIW I think the "old iron" approach is better value for money if you have the space, the ability to move the machines, and the skills/willingness to assess/patch up ailing machines, but that's more a comment on the compromises inherent to all small, value-engineered machine tools.

I know a good number of people who were fortunate enough to be able to move from exquisitely manufactured Myford's with all the bells and whistles to modern full size lathes from Warco et. al. and found it to be a big step up despite the supposed superiority of manufacture/finish on a Myford; I doubt they'd see the same level of performance jump by buying a new Trens or Colchester to replace their new Warco or Chester.

Ultimately engineering is all about optimisation problems, and choosing machine tools is no different; each user has to optimise for their use case and decide what the right balance to strike is. For me a WM250V or the like is a frustrating machine to use, but that doesn't make it a bad machine, just a slow one by the standards of a user who fully acknowledges their impatience...

Edited By Jelly on 10/11/2022 14:21:07

There are factors which do not seem to have been considered: The evidence shows (a) that damp (at least) has affected this machine, and no check seems to have been made about other (hidden) areas of steel which might also be affected, or on the effect on the switchgear and any electronic parts. Both these will require examination when both parties are present, and any subsequent acceptance by the new owner should be conditional - in writing - on any hidden faults being sorted without further question.

and (b) that Warco (if they are indeed the supplier) have not complied with their own stated pre-delivery procedure. This makes it doubly important that Warco are invited to be 100% involved in any checks and rectifications. If another supplier, then it depends on what claims they make about checks, etc.

I speak from experience in the warranty dept of a major manufacturer. Hope this helps

Cheers, Tim

A Q for Jason - can you explain what is the distinction you make between a brushless motor (for a lathe) and a 3-phase motor with inverter?

I am aware that a brushless motor can be made for other phase details that three - but I'm sure that is not the factor in question here.

I was thinking (until today) that the two descriptions which you distinguish here are just different ways of saying the same thing.

Regards - Tim

PS my Colchester has a motor without brushes and is run from an inverter via three wires of different colours (none of which is earth).

Edited By Tim Stevens on 10/11/2022 15:57:59

Tim, it's not so much the technical distinction so much as people being wary of "brushless" equiped machines.

Many still class them as no different to early far eastern offerings that may have go a bad reputation and think they will go pop as soon as you look at them and therefor prefer the inverter and AC motor route

Many are wary of possible problems with control boards and being tied in to really having no option than to replace like with like if they fail .At least with an inverter driven item it's relatively easy to get another generic inverter and replace.

In a similar vein the brushless motors will likely have to be replaced with a spare from the supplier as they are not so easy to come by and as a flange or foot mount motor that can be easily had and swapped if the Brushless motor gives up the ghost. The additional wiring for speed sensors etc that the brushless motors tend to have would need to match that of the board. Typically 9 wires to a brushless motor found on these machines.

Then we come to usability and getting the best out of the motor, Despite what different specs Amadeal have on their own site their brushless 250 has two speed ranges approx 50-1000 and 100- 2000rpm. Whereas the Warco has something like 30-500 and 120-2000rpm. From that you can see that for the same speeds in low range the Warco's motor will tend to be running faster and nearer to it's optium speed which means you won't suffer as much the loss of performance due to running the motor at less than ideal speed so less chance of stalling the lathe when turning larger diameters at slower speeds.

Edited By JasonB on 10/11/2022 17:14:13

Jason,

Stalling at low speeds isn't a disadvantage. It's saved me a few broken tools and damaged workpieces on tricky work with small clearances and high collision risks. I gather you have to hit the stop button sharpish to avoid electronic damage, but in 7+ years' regular use I've never had a problem of any sort in that category.

I have the lathe so it will slip it's belt. The mills have a very good trips, almost too good. Neither results in current still going to the motor when it is not rotating maybe that is why I have not had problems with motors or boards in 15yrs of ownership and they do get used.

It can also be a disadvantage when you can't cut at the right speed for the cutter diameter/material for example having to run a HSS slitting saw at 50% or more over the ideal cutting speed may shorten it's life. Or having to take very shallow cuts at fine feed when turning a large diameter part on the lathe particularly if you are of the HSS turning tools are the only way school of thought.

I was under the impression that "Brushless" refers to a Electrically Commutated DC Motor whilst a "3-Phase Motor" would be generally taken to as referring to an Asynchronous Induction Motor.

I suppose that the inverter drive (which is rectifying an AC input to DC then chopping it up with rapid switching to make a facsimile of a sine wave to produce the 3-phase AC output) is powering the 3-Phase offering does make the practical difference less clear; as it's doing a similar thing to create the waveform as the Control Board for the Brushless Motor is doing to "Electronically Commutate".

​

In practical terms the big differences are:

If you have a 3-phase motor:

• you can put a Red CEEForm (Commando) plug on it and it will run off mains 3 phase (or a converter supply) just like that, because it's a native AC motor.
• this also means that it's independent of the inverter used to supply it in a single-phase system, because it can use anything which gives a 20-400Hz three phase output (older motors are nominal 50 or 60 Hz but newer motors designed since the dawn of VFD's are usually rated to run between 20-400 without faults developing).
• it's a standardised interchangeable product in it's own right, which is widely available everywhere, with a solid secondhand market, but comparatively expenisive new.
• They last forever (life expectancy in the region of 130,000 hours of operation with new bearings every 25,000 hours, compared to a life expectancy of around 10,000 hours for a brushless motor).
• They're cheaper at high power outputs (£295 for a 7.5kW induction motor vs £3,091 for a 7.5kW brushless motor).

​

If you have a brushless motor:

• you need to have the correct control board and motor driver, in operable condition, for the specific model of motor, or it can't run and those electrical elements are not interchangeable parts so compatibility and manufacturer support become an issue.
• whilst some standardisation exists, especially at the lower cost end of the market they have a tendency to be proprietary, which can lead to supply chain issues if you have to replace it.
• there are a range of different speeds and speed-torque characteristics available, and you can select an appropriate model from a manufacturer's range to suit your exact use case (including picking one with embedded sensors which can be read to provide feedback to other systems as a cheaper alternative to a position/step sensor or servo for some NC/CNC uses).
• they're generally somewhat cheaper at the smaller end of the size range (£113 for a 1kW brushless vs £178 for a 1kW Induction motor, with the differential going up much higher in favour of brushless as the power goes down)

So there's not a clear winner, just things which make both options more or less suitable for different users and machines, with induction being a natural fit for high-power or long runtime, and brushless a better fit for high speeds or reduced cost in low power applications.

In a Colchester lathe like Tim's the induction motor would be the only sane choice on cost grounds (I'm not sure what lathe Tim has exactly, but even on AliExpress a brushless motor suitable for a Student at 2.2kW is exceeding the price for an induction motor from a UK supplier).

Edited By Jelly on 10/11/2022 18:40:23

That's my understanding too, and the main physical difference is the way the rotor is magnetised.

A typical 3-phase motor has a stator with three windings and a solid rotor with shorted copper straps running end to end. When the stator is energised, creating a rotating magnetic field, currents are induced in the straps, causing a magnetic field in the rotor late compared to the stator, so the rotor spins trying to catch up. RPM is related to the AC frequency except the rotor slips so the motor is asynchronous. Many advantages, notably simple reliability. but power is 'wasted' generating the magnetic field in the rotor, and doing so by induction across an air gap. It's possible to do better.

A brushless motor also has a stator with three windings, but the rotor's magnetic field is provided by permanent magnets. Thus no power is wasted by induced currents and the motor is synchronous. This type is relatively new on the scene because they depend on powerful permanent magnets that can take heat. Not easy - although super-magnets were invented in the late 1970s, they took nearly 30 years to become affordably bullet proof.

Early brushless motors with older magnet technology couldn't compete with 3-phase induction motors because the magnets weren't powerful or permanent enough, plus the electronics needed to drive them were expensive in 1970! Now good affordable super-magnets and electronics are available, brushless are supplanting 3-phase induction motors in many applications. In comparison brushless are lighter, more reliable, more efficient, and have better power, torque and speed control characteristics.

Another difference is 3-phase induction motors prefer to be powered with something approaching a sine wave, which limits how much oomph they can take. Brushless are powered by DC pulses with a higher power density. In the graph, the area coloured green is the additional power delivered by a square wave compared with a sine wave, about double:

Dave

It seems we have another confusing term, or two, to add to my list.

Brushless doesn't just mean it's got no brushes, it means it also runs on DC.

And the drive for my lathe, which has a brushless 3-phase motor, is not called brushless, but an Induction Motor - an expression which actually covers almost all electric motors, from Faraday onwards, and tells us very little to distinguish one type of motor from another. It is fortunate indeed that electricians don't write dictionaries.

It seems that it is all a plot to prevent people who try to speak and write accurately, so they can be understood, even by those whose English is a second or third language, from succeeding. Well done, I say - but when I say well I mean a deep hole with water in, and done is what you call toast when it is brown.

Cheers, Tim

In my day, brushless motors were properly called "brushless dc motors" ...you wouldn't have expected an ac motor to have brushes.

I suppose it all depends on who you are speaking to or writing for as to whether they will understand you. I would say most people under 30 will take a brushless motor a being what gives their drone, RC model, CNC router, etc better performance than a bog standard DC motor and that a 4S Lipo has nothing to do with weight loss.

No electro magnetic motor will run with DC applied to its coils. Regardles of what the supply is, at least one of the coils musthave alternating current flowing through it to rotate. On a brushed DC motor (permanaent magnet or wound) the brushes do the switching. This makes it simplier to switch the rotor and have (in permanent magnet versions) the magnet in the fixed part. With solid state switching it is pointless to pass the current through slip-rings and brushes so the magnets go in the rotor. So the full name is "electronically commutated permanent magnet rotor DC motor". Brushless DC is easier. Lets not go down the rabbit hole of how stepper motors, permanent magnet AC motors and AC servo motors differ).

There is nothing to stop you having a polyphase AC (sine or switched current) stator with a wound DC rotor. I've run a car alternator as a motor on 400Hz 3 phase with the rotor current cotrolling the maximum torque.
The "universal" brushed motor is a form of this.
There was a class of large AC machines used in aircraft systems that used a wound rotor carrying DC but no brushes. A small coil carrying DC was part of the stator and was coupled to a 3 phase winding on the rotor. There was also a rectifier on the rotor that converted the AC from that to DC for the main rotor winding.

Robert.