Chinese lathes

[V8EngParticipant @v8eng]

This is how Pam Ewing must have felt when she woke from the worlds longest nightmare, to find Bobby safe and well and taking a shower

 

 

She should have been in there with him, saved a lot of bother.

Edited By V8Eng on 27/11/2010 18:51:06

[Chris TriceParticipant @christrice43267]

1. No one has “a reasonable expectation’ that a light bulb lasts for ever but they would have ‘a reasonable expectation’ that a lathe would last longer than a light bulb. A bulb in most peoples minds is a consumable. A lathe is not.

 

2. No one is suggesting that any legal actions are necessary. The discussion, I thought, was about the underlying principles.

 

I agree with TerryD. We get the service we deserve. If the customer has a legitimate complaint, whether he can enforce it with any tenacity is neither here nor there. As a point of principle, the dealer should attend to the complaint rather than use the difficulty to avoid a moral responsibility.

[The Merry MillerParticipant @themerrymiller]

I notice in this month’s MEW an article that stated, many machinery dealers refuse to buy second-hand imports but are still are exporting quality used British, Continental and American machines to the Far East.

Wouldn’t that be ironic if those Far Eastern chummies are using our stuff to make their stuff, (castings excluded)

 

Len P.

[John Stevenson 1Participant @johnstevenson1]

Len,

Probably to melt them down.

Because of foreign investment prior to the hickup with the economy China has more than enough funds to buy new.

 

Last time I was over there and saw one of the plants they had rows and rows of new CNC with China Fadal on them, they even make their own plant.

 

This is an except for a Bloomberg finance page only this weel on Fanuc, the Japanes machine tool controller.

 

“Foxconn, the Apple supplier  buys 800 programmable Robodrills from Fanuc every month — for about $62,000 each — to make the stainless steel band that wraps around the iPhone. “

 

From Terryd

“

Dear John S,

 

I suppose you are one of those who moan about the nanny state and then moan when every mile of road in the UK is not gritted within the first 10 minutes after it snows and never carries emergency equipment or warm clothing in the car in winter. Expecting the emergency services to be there to aid you within a few minutes if you break down.”

 

Yes I do moan about the nanny state, when teachers have a 50 page book to read about how to treat pupils and another 50 page book [ no joke this is true ] on bullying.

They can’t play conkers in the playground and some schools have even banned running in case one of the Herberts slips.

 

Don’t get me started on H&S, we have more to fear from that than any of the unions in the 60’s and 70’s 

 

Snow ? what’s that ? had about 2″ of decent frost this morning , last decent snow I remember was prior to 1990 when we sold the truck garage. 19 years of being dragged out by the police when everyone else was tucked up nice and warm to travel the wrong way down closed motorways in 8 foot visibility when we had 10 feet of bonnet in front of us to pull some poor bastard [ expletive deleted but it means someone who’s parentage is in doubt ] who has crammed a 38 tonner into the back of a steel lorry.

 

No silly “Oh dear my fan belt has broken” but sit there waiting whilst the ambulance and fire crew cut what’s left of some poor sod out before we can get chains on what’s left.

 

I don’t drive a car, I prefer a van, suits what I do far more. It carries enough warm clothing for everyone who can travel in it, a trolly jack – hate those bent bits of tin you get with nannymobiles and even a 1 tonne folding crane – just in case.

 

If I do have to call the RAC out and it has happened I must admit I sit and wait because I have a deep regards for the work they do and how idiots treat them having been roughly in the same boat. Fortunately we didn’t have to deal with the great unwashed public.

 

John S.

[adyParticipant @ady]

a trolly jack – hate those bent bits of tin you get with nannymobiles

 

Got to admit a trollyjack cant be beaten.

Got fed up of bashing my knuckles on the kerb and roadway years ago with those scissorjack things.

Slip it under and up goes le car, a doddle,  job sorted.

[Eric LougheedParticipant @ericlougheed54619]

This thread started on the subject of CHINESE LATHES ETC. and shortcomings therein.

Mine has a wobbly top-slide: take it off, clean everything carefully, re-assemble and start cutting again – within a few minutes there is discernible deflection at the tool tip!

 

I saw an advert in an American magazine (American Machinist ?) for a 4-bolt anchor plate for the top-slide (replacing the ‘as issued’ 2-bolt system. Allegedly this obviates tool-tip deflection, but at some cost! 

 

Has anyone experience of this? Or comment to offer, please?

Eric Lougheed 

Strathclyde 

[clivelParticipant @clivel]

Posted by Eric Lougheed on 27/12/2010 21:19:41:

I saw an advert in an American magazine (American Machinist ?) for a 4-bolt anchor plate for the top-slide (replacing the ‘as issued’ 2-bolt system. Allegedly this obviates tool-tip deflection, but at some cost! 

 

 You don’t mention what size lathe you have, but earlier today I came across instructions for making a 4 bolt anchor plate for a 9×20 Chinese lathe:  4 Bolt compound clamp for 9×20 lathe

[John Stevenson 1Participant @johnstevenson1]

Eric,

Do you need a top slide for everyday work ?

 

No I’m not joking, I have taken the top slides off the two lathes I use the most and stored them in the lathe cupboard.

They have been replaced by large chunks of steel that hold the quick change tool post.

Rigidity for me on everyday straight turning jobs is worth far more than the odd small taper I need to do  just a few times per year.

 

When I need to use the top slide it’s in the cupboard with a sharp tool in the original 4 way holder, so just two studs and nuts to undo and swap over.

 

John S.

[Sam StonesParticipant @samstones42903]

John S,

 

That’s a brilliant suggestion.

 

In all my 60+ years of lathe-work, I have never even heard of it.

 

Would you also add for beginners, that a calibrated hand-wheel on the end of the main leadscrew would be useful under these circumstances?

 

Sam

[JasonBModerator @jasonb]

John how do you deal with say turning a simple shouldered bush does your carrage handwheel have the divisions to feed in fine enough increments to get the correct step?

 

At best mine is calibrated with 0.050 increments or are you using a DRO?

 

J

[John Stevenson 1Participant @johnstevenson1]

One lathe has a calibrated hand wheel on the apron, marked in 1/2mm increments and it’s possible to halve these by eye so that 1/4 of a mill or 10 thou in old money.

Other lathe has provision for the hand wheel but it’s not fitted so that’s down to working with a 6″ rule.

Again you gen get to 10 thou without a problem.

 

For 90% of the work I do this is fine enough, if I need to work closer I tend to go further and then face to the dead length.

 

A calibrated hand wheel will help for some but the only lathe I ever had one fitted, a ML7, because it meant engaging the 1/2 nuts to use I never got into the habit of using it, however not all people work the same way.

 

One lathe has the older type BW Electronics DRO where it pulls a wire off an encoder drum, the cross slide is still connected but the carriage isn’t. To be honest I don’t find it as accurate as the dials.

 

The other lathe that’s in constant daily use has a glass scale DRO on the cross slide but no carriage scale because I don’t need it.

Even on the cross slide I only use the DRO to get close and micrometers and the dial for final cutting.

Most of my diameter work is close, bearing fits to a couple of tenths and the lathe is good enough to get this on dials alone.

 

John S.

[Tony JeffreeParticipant @tonyjeffree56510]

Posted by Sam Stones on 28/12/2010 02:28:23:

John S,

 

That’s a brilliant suggestion.

 

In all my 60+ years of lathe-work, I have never even heard of it.

 

Would you also add for beginners, that a calibrated hand-wheel on the end of the main leadscrew would be useful under these circumstances?

 

Sam

 

 My first lathe, a Peatol, had neither a calibrated handwheel for saddle traverse (rack-and-pinion, no leadscrew) nor a topslide (well, they do sell a topslide for the lathe, but after trying it a couple of times it proved to be (a) a pain to set up and (b) about as rigid as high tensile jelly). So I got used to finding other methods for measuring to shoulders etc.. I now also have a Myford ML7; I have removed the topslide from that lathe and replaced it with a solid toolpost machined from aluminium bar, with the QCTP mounted atop that. I don’t miss the topslide at all; for many uses it just isn’t necessary (and as John points out, reduces the lathe’s rigidity), and for the few cases where it would be helpful I have alternative methods available to me as the lathe is now converted to allow either manual or CNC operation. The latter allows me to do full CNC control where that is appropriate, using Mach 3, or a rather simpler form of CNC control using one of my trusty Divisionmaster controllers. While the latter was originally sdesigned to drive a rotary table, it is easy enough to set it up to drive the lathe’s leadscrew, and cutting accurate length to shoulders then becomes a doddle. The other day I needed to graduate a thimble (part of the Worden grinder that I am building) with 25 divisions; I had one Divisionmaster controlling the indexing, via a worm drive engaged with the lathe’s bull wheel, and another driving the leadscrew to give me accurate-length witness marks on the thimble. However, for probably 95% of the work the lathe does, it operates in manual.

 

Regards,

Tony

[John OlsenParticipant @johnolsen79199]

The Unimat 3 as supplied uses just the leadscrew for left-right movement, with a calibrated handwheel on the end. There is no rack, and no clasp nut, eg it is not a conventional screwcutting lathe. (There is a hob attachment but I didn’t think it looked very useful.)

The leadscrew handwheel does provide quite a useful way of working, although one recommended mod is to provide yourself with a zeroing dial as this saves a lot of time. I do have the little topslide for this lathe, it is useful for little tapers etc, but you would not want to leave it there all the time.  It would get in the way too much.

 

I guess it is perfectly feasable to work in the same way on a larger lathe, especially if you have the means to disconnect the screwcutting gear train easily. I have a gearbox on the Myford, so dropping out the last selector is easy, I wouldn’t want to have to take off the quadrant all the time.

 

regards

John

[JasonBModerator @jasonb]

The problem with a lot of larger lathes is unlike the Unimat they have no handwheel on the end of the lead screw so you have to rely on the carrage wheel which is not the easiest thing to use to put on small cuts and the dial is not callibrated in small divisions.

 

I used to have the geared head Emco Ecomat8.6 which had a 16tpi lead screw and the handwheel on the end was calibrated in 0.0005″ divisions, 0.0625″ per rev. I didn’t use it for turning much but it was ideal for use with teh vertical slide.

 

Jason

[Ray LyonsParticipant @raylyons29267]

Has anybody had any experience of importing direct from China?. I was thinking of upgrading my cutter grinder to one of those Universal Grinders as advertised by some of our tool suppliers. On downloading the specifications, I found that although the same, the prices vary considerably from £655 to over £1200 including the accessories.

I contacted the manufacturer in China and was quoted £471 including delivery by sea. Added to that would be import duty and VAT which I calculate to £579 total. £1200 is quite a mark up and would make the effort to buy direct worth while.

The accessories show the biggest difference. Each attachment cost £16 ex the factory with the diamond wheel costing £13. I have not seen any of the attachments buy they look similar in the specifications. For instance, the price of the endmill sharpening attachment in UK is between £80 and £100, compared with about £20 from China. They also supply a higher specification machine, the GD-U3 for an extra £100 which now has me wondering if to this is the route to take.

If anyone has experience of dealing direct I would like to hear their comments.

I wonder how much a lathe or a mill would cost buying direct.

 

[Ketan SwaliParticipant @ketanswali79440]

Depending on who you buy from, MOST of the Universal Griders from China DONOT have “real” CE certification. Both with and without are available on the U.K. market. In any case, you will need to be careful with what you buy. A prototype exists of one of the clones with John Stevenson, which he had to modify.

 

These are grinders with high speed spindles. Another prototype has been known by me to have the grinding wheel come off during operation and fly past the users right ear. All be it that it was the users fault for not checking the lock nuts, but that event put me right off bringing it for sale.

 

On the risk guage, probability of injury is high so if you are dealing with a non-CE product, I would suggest you to keep off, like I did. Even with CE compliance, be careful. I do not know how some traders are still selling the non-CE version.

 

Still, if you take the risk, did the price quoted include clearance charges?. Usually they do not. Depending on how little the seller paid for the carriage to the Chinese shipping forwarding company, will effect how much more you will end up paying for clearance and delivery – anywhere upwards to GBP125.00 extra for clearance and delivery, plus VAT. Rest is up to you.

 

Profits margins on lathes and mills are crap, so buying small hobby machines from China direct will probably not save you any money – not to forget – no back-up when things go wrong

 

You dont have to believe me. SIEG will not supply you directly. Others might. Risk is yours.

 

Ketan at ARC.

[Eric LougheedParticipant @ericlougheed54619]

Ray,

I would only remind you of comments made by an American several years ago, anent Chinese Lathes: his machine needed a complete strip, degrease, re-assemble and adjust; but then became a good machine.

He said that the original grease looked like refinery floor-scrapings!

That said, perhaps the heavy mark-up covers the cost  of preparing machines for re-sale (or placating those clients who actually complain!).

Eric Lougheed 

[Eric LougheedParticipant @ericlougheed54619]

May I ask another question, please?

I’ve fabricated a 4″ square x 3/8″ hold-down plate for the top-slide. Not quite as per the drawings proffered earlier, but very similar.

However, when I switched on, no response!

Previously there had been intermittent difficulty in starting – motor starts, lathe runs, lathe stopped (for check measurement etc.) , lathe refuses to re-start. After some time, and turning the machine by hand, it would re-start – but not predictably.

I had wondered whether something was over-heating in the motor, or some safety element was being over-sensitive. But it had been getting progressively worse – and now ‘dead’.

(When first in use I could stop and start very frequently with no trace of difficulty.) 

I’ve checked wiring, switches, etc. as best I can and found no obvious fault. 

But inside the wiring system is a 12-pin relay, powered by a low voltage transformer (which shews no open-circuit faults in the windings).

Could any kind soul suggest ways of testing the relay, please? I have only a pocket meter for resistance, continuity, voiltages, etc.

Eric Lougheed 

 

 

[john swift 1Participant @johnswift1]

Hi Eric ,

what model of lathe  do you have ?

 

and is the wiring and circuit diagrams available as a free pdf manual download

 

if it has a dc motor like in the C3 minilathes

and the motor starts when you turn the spindle by hand

i’d check  for loose wires , the interlock switches on the chuck guard  etc

and the length  of the motor brushes

 

 with the info for your lathe  some one wiil be able to give you

more exact tests to solve the problem

 

 John

[Mohammadreza rezaParticipant @mohammadrezareza92277]

i have a master of science degree  in industrial engineering field and i like modeling concept especially in railway and train, please help me about how i can start,
best regard

[Anthony SalisburyParticipant @anthonysalisbury72898]

Morning,

Just spent the last hour reading all the posts regards the “quality” of the chinese machines.  I have a Warco GH1224 so slightly smaller than Lathejacks machine.  I had run the machine for about 18 months and something just wasn’t right with the machine. As Lathejack has done I took the machine apart.  I found the same types of problems.  Sand / swarf in the headstock oil.  Items installed onto the spindle that looked like they had been bashed around with a hammer and holes drilled like they where drunk.

 

I replaced all the bearing in the machine with skf put the machine back together and the rattling has now gone.  The machine is great now although I still have oil leaking from somewhere.  I’m not too pleased with the build quality but as you say…….you get what you pay for.

 

I manage the installation of multi-million pound CNC Milling machines / production equipment and I would not accept these types of errors on the installation.  But I know how much a lathe at the high end of the market costs and the chinese builds are pretty good for their money.

 

I would like Warco to increase there quality control on the build of the machines but in the end that would just increase the price of the machine to the end user and I’m sure if you asked everyone all we want is a reasonably cost machine.

 

Anyway thats only my thoughts.

Thanks

Ant 

[Eric LougheedParticipant @ericlougheed54619]

Thanks to John Swift – it is an Excel PL-916.

The control box includes a low voltage transformer and an 11-pin relay. The transformer seems to give almost 40v, and an 18v battery makes the relay click most convincingly.

But following through the wiring (the lathe manual electrical information amounts to a joke in very bad taste) I find only about 4v flowing through the micro-switch fuse & circuit. 

AND, it looks as though I’ll have to dismantle most of the drive system to inspect brushes! 

 

Has anyone met this problem before, please? 

 

Eric Lougheed 

[john swift 1Participant @johnswift1]

Hi Eric

 

I’ve had a look at excel machine tools web site but can’t find a picture of the PL-916

or download the manual

 

if your machine doesn’t have a speed control like the CL300M minilathe

and is more like the Warco GH1224

the motor is more likely to be a single phase induction motor ( with no brushes)

 

a scan of the wiring diagram would help

does your machine have an electric brake like the Warco lathe ?

 

  John

[Eric LougheedParticipant @ericlougheed54619]

I’ve responded to John directly (couldn’t get the thread message panel to respond), but the number is PL-918, NOT 916!

Speed control is by simple belt-changing.

There is no wiring diagram, only directions for running on 240v or 110v. (changing links on the drum switch )

I’ve bought spare nylon drive train gears from Chester’s before, but no response yet to my technical enquiry. 

Eric Lougheed 

[john swift 1Participant @johnswift1]

having read the available info on the pl 918

i’m convinced the motor is an induction motor

 

if you can see the coil voltage on the relay

you may find it to  be 48v ac , with a typical range of + or – 15%  or so

it would work off the 40 volts you measured 

 

this makes sence if  water based coolent can find its way into any interlock switches

like the chuck guard on the machine

 

this is the case for machines like the EMI-MEC SPRINT  automatic capstan lathe

you can touch the wet terminals of the limit switches if you are daft enough

 

 

  John

 

 

 ps  a relay with a coil intended to operate on AC  as you have found out

          works with a smaller DC voltage

 

 

Edited By john swift 1 on 05/01/2011 00:26:21

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