New lathe arrived today : The ongoing saga

[Bodger BrianParticipant @bodgerbrian]

Posted by Brian John on 01/09/2015 11:43:07:

I am curious as to how many lathe owners would go poking around their motherboard with a multimeter Most people do not fix their own TV's, fridges or sewing machines if it develops an electrical fault and I do not see the lathe as being much different.

I would hazard a guess that a large number of lathe owners would be willing & able to 'poke around' their lathes with a multi-meter. Given a basic understanding of electricity – and a healthy respect for the personal damage it can do – tracing continuity of a few switches is hardly rocket science. Model engineers tend to be practical sorts….

TV's are a different matter. I've worked in the electronic industry for over 30 years but there's no way I'd try fixing a TV, beyond checking fuses etc.

Bodger

[HopperParticipant @hopper]

It depends on the quality of the tipped tools you bought. I have found that small lathes don't like carbide tools unless the inserts are the ground finish ones from a good maker. It takes more horsepower and rigidity to cut with the "blunter" carbide tools than a good sharp HSS tool.

No, you need a six-inch bench grinder with coarse and fine wheels to sharpen HSS bits. Then a bit of a rub on the kitchen knife sharpening oil stone gives a nice finish for special jobs. If you are using those little 1/4" (6mm) HSS square bits, it takes less than a minute to sharpen on and a couple of minutes to grind one up from scratch.

[HopperParticipant @hopper]

Posted by Bodger Brian on 01/09/2015 13:15:33:

I would hazard a guess that a large number of lathe owners would be willing & able to 'poke around' their lathes with a multi-meter. ..

Bodger

Guilty as charged sir. I believe there are even some naughty boys who would think naught of twisting the wires together to bypass the suspect reed switches and get going. — but not on a warranty job of course.

[Ian S CParticipant @iansc]

The diamond sharpening stone is OK for HSS or Carbide, unless you have the diamond coated needle files, don't go near the tool tip with it, no a needle or any ordinary file will not sharpen HSS. A good oil stone is very handy, I have some small ones about 70/80 mm long X 20/30 mm wide, and 10 mm thick.

Print out a copy of the instructions that Michael Gilligan put a link to, unless you already have them, read and understand that, and you'll be well on your way to knowing what you are doing.

To get your lathe going, remember that there is a saftey switch on the belt cover at the left hand of the head stock, make sure that cover is closed.

Ian S C

ps In the instuctions they warn you that the tips of the carbide tools need a touch up with the diamond sharpening stone

[AjohnwParticipant @ajohnw51620]

Posted by Brian John on 31/08/2015 17:27:46:

The micros switches are operated by magnets ; there are definitely no pips.

I did ask before about the power of this motor ( I quoted 500 HP ! ) but it is 500 W. I would have thought a motor of this size should be capable of cutting steel but it does not seem up to the job…something I was warned about before purchasing it. I was also considering a SIEG C2 lathe at the time which is a much bigger lathe but only has a 250W motor. But the C2 will cut steel easily so why is that ? I thought the determining factor would be the power of the motor.

It is amazing what you learn once you actually have a lathe in your hands for a few days ie. what works and what does not and which features are desirable on the lathe. Even if I can get this lathe running again, I don't think it has the grunt to do very much…brass and aluminium only.

That is a very good point for beginners Brian. There actually is some sense in buying just to find out. Costs of doing that are actually fairly low because it will sell on the 2nd hand market. I'd guess with this one that you already have mixed feeling about swarf getting on an open lead screw on the compound slide. Your comment on brass and aluminium doesn't surprise me at all. The last person I know that went out and bought one even against advice turned round one day and said it's only any good on plastic to me, not really sure what it's any good for. He bought one because of the low weight. He also had worries about the strength of his shed floor – silly really if as bad as he the implied he wouldn't be able to stand up in it.

The wattage they quote does seem to have it's catches. I've long suspected that input power is quoted, expect up under 1/2 of that coming out in that case. The other aspect is electronic speed control. It really is difficult to get a grip on what that means in terms of torque on the cutting edge of the tool. It might even be extremely low at low speed settings. Speed reduction via belts and gears increases torque – even good electronic speed control doesn't because motors can only take so much current so as the revs go down so does the horse power. Some of the variable speed lathes do have a belt to give 2 speed ranges. The belt ensures that there is more torque in the low speed range. Frankly I feel they should have 3 belt settings not 2. I'd guess some people modify them. Some of these lathes use a gear to provide the lower speed range. Initially metal gearing which can be rather noisy. More recently plastic with metal replacements available if they break. I've no idea if they do.

I suspect as many people are happy with mini lathes you would have been pleased with the next model up – the mini lathe rather than the baby one. This and other reasons is why I sometimes say don't buy a lathe unless it weighs circa 60kg or more – unless you want to do pen turning for instance. Even then swarf will get in that lead screw. The slide that is on wont locate very well either as it's so short.

There are catches with the mini lathe as well. Power seems to vary. Some now come with brushless motors which might be better over a wider speed range. Probably for the same reason that a 6 cylinder engine produces more low speed torque than a 4 and an 8 even more. I've not seen what they have done so can't be certain on that aspect. They will still have a maximum current rating.

Metric versions of the mini lathe sometimes come with screw cutting indicators that allow metric threads to be cut without reversing and stopping the lathe etc – some don't. If you ever get to screw cutting you most definitely will appreciate an indicator even if it can't be used on all of the pitches the lathe can produce. Imperial lathes come with and without as well. This aspect seems to apply to all metric lathes. When provided they usually have several gears which can be meshed with the lead screw and drive the indicator dial.

As to what needs doing to them after they are bought ArcEuro provide a guide. This is why some people call them casting kits and even rework the saddle fit on the bed at times. The arceuro guide is very likely to apply to all of them even Opti – have you looked to see how well the underside of the slide has been machined? Or the fit on the cross wise adjustment of the tailstock if it has that. This is how the costs are kept low – or margins high – not sure.

Well I should add that a lot of people do decent work with mini lathes despite all of this. It seems to be the smallest size where this can be done. I have no idea how often the correct things with files and emery cloth etc.

By the way. Did you check that you haven't pressed the emergency stop button in by accident. Easily done and they latch and need rotating a little to release. On the other hand the variable speed drive electronics do fail sometimes. Often on early a machines so they started fitting an American design which might be better.

The best source of reviews on the web really are blogs and youtube all by ordinary people who are actually using them. Some however will be supported by the suppliers.

John

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Some might suggest buying a used machine. Not an easy thing for a beginner to do as they might buy a load or rubbish. There is plenty about and they can be used but a new machine is likely to offer better general performance even if it has some catches.

John

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[Brian JohnParticipant @brianjohn93961]

There are very few used machines in my area (Cairns). I have never seen any used machines for sale at all. Perhaps I have been looking in the wrong places.

The gear cover door is closed and the emergency stop switch has been released. I have checked this many times.

Desirable features in next lathe :

1. lead screw to be covered.

2. MT2 taper on the tailstock (so many more accessories than MT1)

3. tailstock and top slide/tool post to be locked with a built in lever…not A 5mm allen key.

4. chuck guard (if there is one) should not interfere with the fitting of a face plate

5. make sure that face plates and steadies are available for the lathe ; they will be needed eventually.

6. quick change tool post.

7. decent size : 12'' X 7''

Having said all that, I am going to make do with this lathe and learn as much as I can with it. Working out how to do things with a small machine can be a useful learning experience.

Edited By Brian John on 01/09/2015 13:58:46

[Frances IoMParticipant @francesiom58905]

not sure what you mean by emergency switch being released – the wanted setting to ensure power is for it to be primed such than when touched it will spring into the off position – then needs a reset by pushing down with a slight twist at end.

I suspect you will in end be happier with small HSS tools that would suit the scale and reduced rigidity of the small machine eg homebrewed 3mm HSS bar though you will probably need a small mill to fabricate these without too much filing (a good reason to try making some local contacts eg the Mens shed to see if some help is available)

Personally I wouldn’t dispense with a chuck guard – I’ve been hit on the knuckles by an unguarded chuck on a woodturning lathe and do not wish to repeat experience – likewise I’d be wary of a 4 way tool post on a small lathe as sharp tools are relatively closer to fingers than on larger lathes

[Martin KyteParticipant @martinkyte99762]

I strongly suggest that you are interpreting your Stop Switch incorrectly Frances.

All the Emergency stops I have ever come across are push in to Stop. Usually in a real emergency they are hit really hard too. They should lock off when pushed and in order to release them they require to be twisted after which they spring back out again. The electrical contacts are closed when the mushroom is out and open when pushed in.

[Brian JohnParticipant @brianjohn93961]

The four way tool post would be for a larger lathe, not this one.

What is wrong with using 8mm cutting tools on this lathe ? That size is recommended by the manufacturer.

The emergency switch is NOT on. Please trust me on this : I use this type of switch at work. They are on the garbage compactor, the gym treadmills and all the industrial laundry machines. You twist and release so that it springs back up ; the machine is now ready to go.

Edited By Brian John on 01/09/2015 14:42:23

[AjohnwParticipant @ajohnw51620]

Levers – probably have to make yourself.

Swarf does get on the screw cutting lead screw – depends on the lathe.

Having it get on the compound slide screw can be very bad news it if it gets into the nut. It may cause it to start to jam – move it in the opposite direction if that happens.

Seriously I would also add a screw cutting indicator to the list. In practice they aren't cut that often but ……… An imperial one can also help cut metric threads on an imperial lathe. Still have to stop and reverse but the indicator can be used to allow screw cutting to be disengaged when working up to a shoulder. It goes – disengage, stop lathe, reverse lathe, re engage using the indicator when it's in the same position as it was when disengaged. This work out providing that the indicator doesn't revolve too much during the just disengaged period. It's easy to do in practice but sounds a pain / impossible.

Another thing that it might be worth asking a supplier about is if it's possible to turn work right up to the end of work when it has a centre in it. Not being able to is an easy way of making the centre distance 2" or more than it actually is. Going on a visit to one well known supplier they will know about this and may smile or even laugh. In this case it ruled out several machines they had especially certain ones that looked pretty good in all other respects. These were earlier designs that had been "improved". Much cheaper than making the bed longer.

I'm looking for a small fully metric lathe. Just about everything I look at is lacking in some respect. This might include statements on the web like this is for illustrative purposes, actual machines may vary plus all sorts of things I read and notice about them. My ideal really all considered would be 18" or near centres, even 15, Centre height allowing 2in dia plus space over the cross slide and hopefully T slots even if these are only just at the edge. Plus a cross slide travel that allowed the full swing to be turned with a bit spare. I'd probably find that if the T slots were used the cross slide would lock up so really they are better on the top even if only Myford size. To much tightening will break those but better than the cross slide locking up because the casting has distorted. I should also mention sensible sized chucks for the lathe not ones that are rather small for what the lathe can swing.

Forgot the quick change tool post – a decent one with the lathe – as far as I know highly unlikely.

John

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Edited By John W1 on 01/09/2015 15:30:25

[Michael GilliganParticipant @michaelgilligan61133]

Brian,

I don't know if you have seen it, but here is a useful list of the accessories for the various Optimum lathes … The chart on the first page shows what fits what.

MichaelG.

[Brian JohnParticipant @brianjohn93961]

I am familiar with that list : the fixed and travelling steadies are listed as available for this lathe in the manual. However, they are not carried by the Australian distributors and the German company has not yet responded to my request for information on where to buy them.

As you can see there is no face plate listed for this lathe nor a revolving centre. I have purchased an MT1 live centre which arrived yesterday. I am about to cut off some of the arbor as this lathe requires an MT1 short arbor so quite a bit has to be removed. I have already done this with the drill chuck arbor

Edited By Brian John on 02/09/2015 02:21:10

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian John on 02/09/2015 02:06:37:

I am familiar with that list : the fixed and travelling steadies are listed as available for this lathe in the manual. However, they are not carried by the Australian distributors and the German company has not yet responded to my request for information on where to buy them.

As you can see there is no face plate listed for this lathe nor a revolving centre. I have purchased an MT1 live centre which arrived yesterday. I am about to cut off some of the arbor as this lathe requires an MT1 short arbor so quite a bit has to be removed. I have already done this with the drill chuck arbor

.

Brian,

Am I right in thinking this 'MT1 live centre' destined for use in the headstock ?

If so; you would probably be wise to do a trial fit, before shortening it. … My reading of the manual [p16] suggests that there is a full MT1 in the headstock and a shortened MT1 in the tailstock. [This is quite typical on small lathes]

MichaelG.

.

P.S. … The manual seems rather sketchy about 'between centres' turning [pp50-51]

… Do they expect you to use the 'flange' [item 55] as a rudimentary catchplate ?

Edited By Michael Gilligan on 02/09/2015 08:26:41

[HopperParticipant @hopper]

Re swarf getting on the main lead screw, swarf guards are easy enough to manufacture from a bit of tubing or sheet metal. IT was standard procedure on the old British lathes such as Drummond and early Myfords etc., until Myford started fitting one as standard. And something could probably be made up to protect the compound slide screw in a similar way. A sheet metal swarf catcher to keep swarf off the lathe bed ways might be appropriate too. A square tobacco tin attached to the leading edge of the carriage was the traditional way.

If you can't get a steady and faceplate on the Internet, you can make them up yourself. Tonkins sell round discs of steel that are "holes" they cut out of plates on big jobs. Ideal size for turning into a face plate. Steady can be fabricated out of whatever bits of steel, or even ally, you can get your hands on and either bolted or welded together with a trio of holes drilled and tapped to suit three set screws with brass tips added.

Once you get going with these things, there is no end of tooling you can make yourself, which becomes a hobby of its own!

And you are right about metal lathes coming up for sale in Cairns. Very very rarely do they come up. Occasionally see a Chinese one on Gumtree but not very often. Was a Myford up at Atherton way a while back but way overpriced at $3,000. And there has only been one lathe come up at the local auctions in the past two years, a big Enterprise with 3phase motor that needed a forklift to load it on to my mate's truck.

But I think you will find your little lathe will do OK once sorted out a bit and with the right toolbits and methods in place. That website I posted earlier seems to show some pretty nice work in steel done on the same machine.

Edited By Hopper on 02/09/2015 09:06:11

Edited By Hopper on 02/09/2015 09:21:10

[Brian JohnParticipant @brianjohn93961]

The live centre is for use in the tailstock. Why would it be used in the headstock …I am unaware of this practice ?

The arbor on the live centre has now been trimmed using the rotary tool fitted with a carborundum wheel. The hacksaw barely makes a mark on the surface ; this must be tough steel. I do not know if the live centre will even be needed but it did not cost much so I bought it anyway. When does using a live centre become a necessity ?

If a lead screw cover was to be made then it would have to be fitted carefully as there is not much distance between the carriage and the lead screw.

A carriage stop would also be useful. I am looking at clamps to see what I can use.

How close do you work to the rotating jaws of the chuck ? I must admit it gives me the jitters when I get close.

[HopperParticipant @hopper]

Brian, difference in terminology in different hemispheres I think. Live centre in Oz generally refers to what the Poms (more correctly) call a revolving centre, ie one with a ball bearing inside it to let it revolve freely. Live centre in the UK I believe technically refers to the solid centre that is put in the headstock spindle and rotates "live" with the spindle.

How close do you work to the chuck? To start with probably a half inch or so. Once you get more familiar with things, down to the second or third layer of knuckle skin.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Hopper on 02/09/2015 10:11:12:

Brian, difference in terminology in different hemispheres I think. Live centre in Oz generally refers to what the Poms (more correctly) call a revolving centre, ie one with a ball bearing inside it to let it revolve freely. Live centre in the UK I believe technically refers to the solid centre that is put in the headstock spindle and rotates "live" with the spindle.

.

Thanks Hopper … that's exactly right

… I was thinking [hoping] that Brian was about to try some 'between centres' turning: but evidently he is not.

… It's probably time me to stop trying to help !

MichaelG.

[Gas_mantle.Participant @gas_mantle]

Hi Brian,

My guess is because of different terminology people are getting confused as to what centre you have and what you are trying to do with it.

If you can elaborate a bit more I'm sure more people will help.

Peter.

Edited By Peter Nichols on 02/09/2015 11:57:52

[Ian S CParticipant @iansc]

You would have to watch what you are doing with shortening a live centre, I use Skoda live centres and the rear bearing on these type is about 10/15 mm from the end of the Morse Taper, there is a button on the end to open up for greasing. I think the centres for mini lathes must have short coupled bearings in the head of the tool.

Ian S C

[Martin KyteParticipant @martinkyte99762]

Regarding centres my understanding is this.

If it rotates with the work it's a live centre and if the work rotates on it it's a dead centre.

Centres come either fully hard (a hard centre) or are unhardened (a soft centre).

A centre in the headstock of the lathe rotates with the work (it's a live centre), as there is no movement, so no friction, between the work and the centre it is usual to use a soft centre. This protects the spindle bore and allows the centre to be re trued-by turning.

A centre in the tailstock does not rotate with the work so is a Dead Centre. The point of this centre acts as a bearing surface and needs to be lubricated. It is usual to use a fully hard centre for this. To avoid the friction between the centre and the workpeice at the tailstock end a Rotating Centre can be used instead. This has its own bearing and as it now rotates with the work is also a Live Centre.

So when ordering solid as opposed to rotating centres they come in two flavours, Hard Centres and Soft Centres.

When in USE if you put ANY solid centre in the headstock it will become a live centre.

When in USE if you put ANY solid centre in the tailstock it will become a dead centre.

Hope things are a little clearer now.

regards Martin

[Brian JohnParticipant @brianjohn93961]

The lathe came with a dead centre to be fitted to the tailstock : the MT1 arbor had already been shortened.

I purchased a live centre to replace this. It had a full size MT1 arbor which had to be shortened.

Dead centre is on the right and live centre is in the middle. I also had to shorten to arbor on the drill chuck.

I thought I was ''turning between the centres'' the other day when I was attempting to reduce the 6.35mm silver steel rod down to 6.0mm. I initially had only 20mm of rod protruding from the chuck in order to centre drill it for the dead centre. Once this was done I moved the rod out to 100mm until it was supported by the lathe chuck at the headstock and the dead centre at the tail stock. Isn't this turning between the centres ?

Edited By Brian John on 02/09/2015 13:08:24

Edited By Brian John on 02/09/2015 13:09:05

[AjohnwParticipant @ajohnw51620]

This is turning between centres

John

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Edited By John W1 on 02/09/2015 13:18:07

[Neil WyattModerator @neilwyatt]

In the old days you had dead centre lathes. Technical still the type of lathe best suited for producing totally round work

These had two non-rotating centres opposed to each other, like on a pole lathe or watchmakers' turns..

Along came lathes with a rotating spindle, The centre fitted to that was the 'live' centre.

When centres which rotate but fit in a fixed tailstock appeared naturally some call these 'live' as well.

Strictly:

Live centre – fixed centre fitted in rotating spindle.

Dead center – fixed centre in fixed spindle/tailstock

Rotating/revolving centre – one that can spin when fixed in tailstock.

Neil

[AjohnwParticipant @ajohnw51620]

Another way of producing work that is likely to be both round and precise is the travelling steady. It can be beneficial to cut away from the headstock as well and also use a loose centre – one that is not tightly engaged. If it was tightly engaged it can interfere with the natural tendencies fixed steadies have.

What amazes me about tailstock centres is all of the work I did with a none rotating ones lubricated with some company provided tallow. I'll always wonder what animal it came from. Probably pixies or goblins as it was magical stuff. Also the best tapping and die lubricant I have ever used.

John

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[bodgeParticipant @bodge]

Tallow . bovine as in cattle , nearest substitute probable dripping.

bodge

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