Emcomat 7

[Martin Shaw 1Participant @martinshaw1]

I have an opportunity to purchase a 2nd hand Emco 7, that comes with 3 and 4 jaw chucks, quite a few Dickson style tool holders and I think other tooling as well for something like £700. An acquaintance of mine is selling on the contents of a late friends workshop and I am in no doubt about the provenance of the machine and am told that it is in full working order. This would replace the Sieg SC3 that I currently have which works well enough, so is this a sensible move forward do you think?

Regards

Martin

[Martin Shaw 1Participant @martinshaw1]

[Gordon TarlingParticipant @gordontarling37126]

Providing that it will meet your needs, I'd say go for it! I've had a Compact 8 for a few years now and am very happy with it, so I would have no qualms regarding the 7. The only real shortcomings I've encountered, which matter to me, are lack of backgear and lack of readily available accessories.

[Steve King 5Participant @steveking5]

I had a emcomat 7 for about 2 year and loved it. It was my 1st lathe. The one i had also had the milling head witch was very useful. I sold it on eday and got £550. as always its only worth what someone is willing to pay but for me if its not got the milling head id be lookinv at more the £400 mark.

[Ex contributorParticipant @mgnbuk]

Nice machines, but I don't think that spares support is great.

I have a dim recollection that there is an issue with the Mazak parts used for some items degrading/failing with age & that spares are NLA, but can't recall where I read that. Gear shift parts for the headstock IIRC.

Nigel B

PS – just been on the Lathes.co.uk site, which must have been where I read of the problems. Worth a read for the description of areas to look at.

Edited By mgnbuk on 03/02/2020 12:46:59

[SillyOldDufferModerator @sillyoldduffer]

Was offered a Super 7 in good order (but stored for several years) last year and declined it. Not because I didn't fancy it, but because I asked myself a few awkward questions.

First question was 'does this lathe do anything I can't do on my existing lathe?'. The answer was no.

Second question was ''does my existing lathe do anything I want that a Super 7 can't?' The answer was yes, because my existing lathe is substantially bigger than a Super 7.

Third question was 'does my existing lathe have any desirable features I'd be unwilling to lose?' Answer to that was yes too – I'm a metric workshop, and the Super 7 was Imperial; I often run in reverse, and I like having a fast powerful 3-phase motor with speed-control because I prefer carbide inserts.

Other reason I pressed the reject button was the hassle factor: apart from spending money unnecessarily on a tool i didn't need, I would have to sell the existing machine to make room for the Myford, and then sort out the tooling.
SC3 and EMCO 7 appear to be of similar capacity though I believe the EMCO 7 has a smallish single-phase motor whereas the SC3 has a much better 500W Brushless. The EMCO may be more suitable for fine work than a Chinese mini-lathe, but mini-lathes are probably better for beefier general-purpose work. Which is best choice depends on the work the lathe is asked to do.

As always buying second-hand, condition is everything. Forget brand reputations, and check the actual machine you are buying! Read what the excellent lathes.co.uk have to say – with good reason they recommend opening the headstock to check the gears and selector before purchasing an EMCO.

I'd say if there isn't a clear and obvious reason already for wanting to replace an SC3 with an EMCO 7, it's not worth the bother. On the other hand, think of the fun you could have with a new lathe!

Dave

[CirclipParticipant @circlip]

" I believe the EMCO 7 has a smallish single-phase motor whereas the SC3 has a much better 500W Brushless."

And the "Small" single phase motor is also brushless and doesn't have the advantage of an expensively replaceable electronic drive.

"SC3 and EMCO 7 appear to be of similar capacity "

Should be as the Chinese copied the original Emco range.

"with good reason they recommend opening the headstock to check the gears and selector before purchasing an EMCO. "

4 cheese head screws and less than five minutes to check.

Regards Ian, proud owner of a V10 with "Edged" gears thanks to a p**t that couldn't read or understand the label on the headstock "STOP LATHE TO CHANGE SPEED"

[JasonBModerator @jasonb]

I had the slightly larger Emcomat 8.6 for 20years and only really changed it as I needed to turn a few larger diameters. never had problems with the Mazak parts or switches and the only part I had to buy was a replacement toothed belt that I got from Emco via Pro Machine Tools even though it was long out of production.

Edited By JasonB on 03/02/2020 13:14:18

[Douglas JohnstonParticipant @douglasjohnston98463]

Dave has summed up the situation rather well I feel, and in a way I will have a similar situation at a local auction tomorrow. There is a rather nice small unimat lathe in the auction and I rather fell in love with it at the viewing. Do I really need it, will it do anything my current lathe can't, is there a space for it in the workshop? All the answers are in the negative, but none of that will stop me bidding for it. Sometimes the heart should rule the head so I might just get carried away at the auction.

Doug

[Ady1Participant @ady1]

The usual reason if you have room for getting more than one is to get them doing different processes

[Ex contributorParticipant @mgnbuk]

the EMCO 7 has a smallish single-phase motor whereas the SC3 has a much better 500W Brushless.

I would sooner have a 250 or 375W induction motor and a gearbox than a 500w brushless drive That way I get increasing torque at the spindle as the speed reduces and constant power – the variable speed drive gives you constant torque and reducing power as the speed drops. The simpler control of the induction motor is also attractive.

But to each his own.

Nigel B

[SillyOldDufferModerator @sillyoldduffer]

Posted by mgnbuk on 03/02/2020 19:16:21:

the EMCO 7 has a smallish single-phase motor whereas the SC3 has a much better 500W Brushless.

I would sooner have a 250 or 375W induction motor and a gearbox than a 500w brushless drive That way I get increasing torque at the spindle as the speed reduces and constant power – the variable speed drive gives you constant torque and reducing power as the speed drops. The simpler control of the induction motor is also attractive.

But to each his own.

Nigel B

May be a misunderstanding about what a DC Brushless Motor is? Single-phase motors have few advantages other than they run off ordinary domestic AC. The way they achieve that trick is a compromise, not best practice. It's well known 3-phase motors are smoother, more efficient, have better torque, and are more reliable. Thing is, a brushless DC motor is more like a 3-phase motor than a single-phase is. Brushless DC motors are a 'good thing'.

When the Emco lathes were designed it made perfect sense to fit single-phase motors because power supplies back then were expensive and unreliable. Today less reason to put single-phase motors on machine tools because electronic controllers for brushed and brushless DC motors are cheap, as are 3-phase VFDs.

As motors go, single-phase types aren't quite a hissing and an abomination, but only Universal Motors have worse characteristics! Not usually worth upgrading a working single-phase motor on a small lathe but I'd certainly recommend replacing a broken single-phase motor with better, probably a VFD and 3-phase. You can be sure an Emco upgraded with a brushless DC motor would be an improvement over the original.

Dave

[JasonBModerator @jasonb]

As Nigel says it is not just the motor size it is the whole drive train that affects the characteristics of the lathe. Having a gearbox will mean that the motor is always running at it's sweet spot so you get all the power so they don't need to fit higher wattage ones to compensate for the poorer slow running. Also you can bet Emco were quoting output not input as many hobby lathe sellers do.

Far easier to stall my 280 that the old Emco with similar size cuts, likewise I can stall the brushless direct drive SX2.7 doing a similar cut and speed that the X3 with it's two speed gearing will happily cope with.

[Ex contributorParticipant @mgnbuk]

Dave,

Jason's post covers much of my intended reply, but with the added benefit of direct experience of that type of Chinese drive/motor combination.

May be a misunderstanding about what a DC Brushless Motor is? No, I don't think so – the "rotating machines" module of the TEC Level 5 Electrical & Electronic Engineering course I endured as part of my apprenticeship covered quite a lot of motor theory & time spent in the Electrical laboratory of Bradford College plotting the characteristics of various types of motors on dynamometers gave some understanding of how they work and perform – at least that bit was more interesting than the theory of operation of Ward-Leonard & Amplidyne systems, both of which were obsolete circa 1978/9 ! Sadly there was little of use for my subsequent time in industry – variable speed drives were only briefly touched on at the end of the course.

I was installing & commissioning DC drives at the time that brushless systems started to come in – something did did slightly reduce my workload, as brushless motors don't have the commutator, brushgear, rotor overheating problems and dirt induced commutator flash-overs that DC motors did. At least the later microprocessor controlled thyristor drives would shut down fast enough not to get damaged by a flash-over – on earlier versions the thyristors usually failed to protect the semiconductor fuses. But the characteristics were different, which made for problems swapping a conventional DC arrangement for a brushless one – typically a brushless motor base speed is around double that of a DC motor, though the constant power range is greater due to a higher top speed – if a greater belt drive reduction couldn't be incorportated, an expensive in-line reduction gearbox was required to be bolted on to the brushless motor nose to get similar overall performance to the DC motor it replaced.

It would be interesting to see the speed/torque and speed/power curves for your brushless 500W arrangement (something I have yet to see published) – "500W" on it's own without reference to speed tells you very little. Is that 500W at maximum speed (which isn't stated) or 500W between a base speed and maximum speed or what ? Best guess is that it is still basically a constant torque motor like a permenant magnet DC machine, but more robust. These variable speed drives are fitted, I suspect, primarily because they are inexpensive and allow the machine builders to make simpler, cheaper machines. Gearboxes cost money.

The SC3 & Emcomat 7 may be of similar capacity, but I supect that the Austrian machine will be more rigid, better made, nicer to use & capable of heavier use – not knocking the SC3 as the Emco would have cost a lot more, so not really comparing like with like.

Nigel B.

[SillyOldDufferModerator @sillyoldduffer]

Re Jason and Nigel's comments, can we concentrate on the motors? The point I was making was about Brushless DC vs Single-phase motors, neither motor having been fitted with a gearbox. Anyone disagree with my 'You can be sure an Emco upgraded with a brushless DC motor would be an improvement over the original.'

Having dug a little deeper, I'm not sure exactly what motor is fitted to an Emcomat 7? Looks like they have brushes, in which case we need to start again! Can an Emco owner confirm the motor type and power output?

I was careful in my original answer not to compare the 'quality' of the SC3 vs Emco. I'm against jumping to conclusions about the usefulness of machines based on reputation (too much folklore) or date and country of manufacture. I'd rather think about what the lathe is for, how much it costs, how much trouble it will be to fix, and the value of its features to me. Condition is far more important than brand name when buying second-hand: unwise to believe that a lathe over 25 years old is still 'as new'. Doing an analysis based on need generates different answers depending on who you are and what your goals are.

None of this is helping Martin. He asked if it was worth spending £700 swapping an SC3 he's happy with for an Emcomat 7. Not because he particularly wants to change lathes, but because an Emco has popped up as an opportunity. Is it a good buy or not? I suggest the decision depends on what Martin wants of a lathe, but that the Emco and SC3 are similar enough to be not worth the bother. Different answer maybe if Martin was buying his first lathe and for the same money could have either an Emcomat 7 in good nick or a new SC3 .

Dave

[Martin Shaw 1Participant @martinshaw1]

Morning gentlemen.

Firstly thanks for all of the most helpful thoughts and suggestions. When this opportunity arose my thinking was that the Emco would likely be more rigid in the whole saddle/ toolpost arrangement which is something I feel lets the SC3 down, although if one is not in a rush and I most certainly am not, it's workable around. Secondly utilising a gearbox rather than a brushless motor it would not suffer from torque reduction at low spindle speed.

They are both solid enough reasons to consider it, however I took the chance to ring Tony Griffiths at Lathes.uk and ask his opinion. He pointed out the known possible problems, motor switchgear, fibre toothed gears and Mazak gear selector forks and also that the price was on the high side. He most importantly suggested personal inspection before committing. This is a problem, the lathe is in northern France and I'm in Scotland, and having purchased it I would need to move it the 6 or 700 miles at a cost. Additionally spares are difficult or impossible. With all these factors in play I have decided against it, the benefits are somewhat outweighed by difficulties and the nett gain might well be a significant loss.

At the risk of reopening the UK/European/Far East discussion the SC3 works, it's not perfect but it it will do most of what I want and likely need. Brushless motors in themselves are just one solution to the power requirement and not ideal but then neither is a single phase motor, and are for a hobby machine manufacturer probably the most cost effective.

A further thought, if Chinese made mini lathes weren't available what could you buy new around that size? Not much I think which would condemn most of us to do something else for a hobby.

Once again thanks for all the input, an interesting read.

Regards

Martin

Edited By Martin Shaw 1 on 04/02/2020 11:38:04

Edited By Martin Shaw 1 on 04/02/2020 12:00:11

Edited By Martin Shaw 1 on 04/02/2020 12:01:13

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