chineese mills

[BERTOParticipant @berto]

Hi .

Thanks to Springbok my chineese mill is now safely mounted on its stand and levelled up.

I have some thoughts and obsevations about the chineese gear that may be of interest.

After fitting DRO’S to all 3 axises i decided to have a play with them and to compare the original dials to them .

X & Y both showed .002″ variation per turn of the handle {.0984″} – not too bad but compound this over 2 or 3 inches or more and you are way off the mark !

Then i turned my attention to the Z axis and this was where things got interesting !

I wound on 1/4 turn of down feed on the Quill and zeroed the DRO and the machine dial .

I wound on 1 full turn = 2.5mm or .0984 thou .

.0975 was the reading on the DRO so i decided to zero it and wind on another full turn this time i got .104 thou so i set up a dial indicator to see what exactly was going on .

The DRO was correct to within .005″ but why the sudden jump from .0975 to .104 thou ?

The only thing i can think of is the rack gear on the quill is out of whack as each consecutive turn yielded a different reading but the DRO and Dial gauge coincided with each other every time .

I don’t know why the Chineese manufacturers don’t just fit DRO’S in the factory and save the hassle of dials !

I also decided to look at a bigger lathe but one thing that realy annoys me is the lack of cross slide dovetails on Chineese gear .

Most of these lathes don’t even have enough thickness on the cross slide to machine dovetails in them and considering the flimsyness of these machines a rear toolpost for parting off is a must !

One machine had the cross slide stepped down behind the toolpost so they could up-spec the swing over the saddle !

I would rather lose the swing to keep the dovetails !

 

 

 

[BERTOParticipant @berto]

[JasonBModerator @jasonb]

What size lathe were you looking at? My Chineese one has Tee slotted (not dovetails) cross slide and is plenty rigid enough to not need a rear toolpost for parting off. There are also lots to choose from with slotted cross slides.

 

J

 

PS I’d take a look at your DRO installation if its only good to 0.005″ even the chineese scale type should be better than that.

[BERTOParticipant @berto]

Sorry that was .0005″ for the DRO !

I was after something approx 600mm between centres with a 300mm+ swing over the bed .

Here in Australia we may not have the range of equipement available in the UK or USA but as far as i’m concerned ALL lathes should have tee slots on the cross slide .

 

Regards ..

Ian

[adyParticipant @ady]

There are also lots to choose from with slotted cross slides

——-

 

Not at the first time buyer hobby lathe level there aren’t.

And It’s one of those things which is essential for a general purpose hobby lathe.

 

Most “lathe pictures” in adverts are set up to make sure you can’t see this problem until its too late either

200 kilos of lathe has to land on your doorstep before a newbie would even notice

 

It’s something they need to sort, even if they make it an optional extra.

 

…and it must be an optional extra which can be supplied, not one of those optional extras with out of stock permanently pinned against it.

 

————–

edit

 

I reckon that current units can be made smaller and lighter when there’s no slotted cross slide. If you use the current unit setup then the quoted swing decreases when a t-slot cross slide is fitted, from 3.5inches to 3.1 inches kinda thing.

 

It’s that…or redesign a heavier beefed up machine and cut a big chunk out of your margins.

Edited By ady on 05/11/2011 10:15:31

[JasonBModerator @jasonb]

Well maybe not in the mii lathe range which is why I asked what size first, though the Chester Cobra is, the 9x 18/20 lathes are slotted, etc

 

The problem with the larger capacity lathe you are looking for is that you are getting out of the hobby range and they start to do away with the tee slotted slides as its assumed by that time that you will have a mill. Does not help if you want to do boring between centres etc. Your best bet would be to have a sub table that can be clamped to the sides of the cross slide rather than cutting slots into the table but you do loose some swing. If you are only wanting it for parting off then a lateh that size like a Chester Crusader or warco 1224 will be rigid enough.

[Brian Dickinson 2Participant @briandickinson2]

I have just bought a Nu tool from a member of our society who has had it for about 10 years and never used it. It’s OK i suppose for home use. I have not used it in anger yet and hope to do so soon. I think its got to be better than milling in the lathe which i always find tricky to set up.

 

Luckily i will be able to sort the play in the lead screw and adding a drive will improve it no end.

 

Only time will tell

 

 

[David HaynesParticipant @davidhaynes53962]

Sorry if you already stated it elsewhere, but what model of Chinese mill do you have? The Sieg X1/2/3 seem to have a good press, as do Chester and Warco models. The Sieg Super X2 Plus that Arc sell is belt driven (no plastic gear train to fail) with high torque brushless motor and longer table. I don’t know what the micrometer accuracy is on any of these models.

 

Dave

[BERTOParticipant @berto]

The Mill i have purchased is equivalent to the Chester Lux and my current lathe is the same as the Chester 920.

Don’t forget that even though these machines look the same they may have come from different factories and more than likely have different specs .

Maybe Chester specifies they supply thier machines with tee slots ?

My lathe has 2 slots that run lengthways along the cross slide alowing a rear toolpost etc but none of the other machines with larger capacities from the same supplier do .

The machine i was interested in gives an extra 100mm between centres and 60mm over the cross slide .

I did consider making tee slot table that could bolt on to the cross slide but this unit has a stepped cross slide and it has been designed to be shorter in length to allow longer travell .

They then covered the rear of the cross slide with an ugly sheetmetal cover that is removable.

It really is a bit of a Dogs breakfast this unit but on the plus side it comes with a lever type lock for the tailstock , powered crossfeed , geared head and can cut l/h and r/h threads in metric and imperial.

 

I also own an X2 MILL which i have found usefull for small work but i haven’t got around to fitting DRO’S or testing the accuracy of the dials etc.

 

Ian

 

 

 

 

 

 

 

Edited By .001 on 05/11/2011 20:59:36

[JasonBModerator @jasonb]

I would have though you may be able to pick up one of the 280mm swing vari speed lathes over there, they seem available in most parts of the world, I have the Warco one with power cross feed and the cross slide is a decent size with two good tee slots

[BERTOParticipant @berto]

Go to http://www.machineryhouse.com.au and you will see what i mean .

Some of the SEIG stuff is sold here but this retailer is the biggest in australia and has the widest range but nothing like Warco or Chester etc.

There is one other supplier in Queensland calle Minitech that specifically caters to the Model engineer but thier range is limited to a few models and the cost of shipping to new south wales ( 500 miles south ) would be prohibitive . I usually buy my tooling from them as they have a better range of gear that suits the model engineer and the owner of the shop knows what he is talking about.

I had a look on the Warco website and thier machines seem to be made to a much higher standard than the ones we get here.

I suppose the importers have to look at what we will pay for when they decide what to bring in to the country .

 

Ian

[Bill PudneyParticipant @billpudney37759]

For what its worth, at different times I got both my Sieg C3 Mini Lathe and X2 Mini Mill from Minitech. The freight costs of both machines has disappeared in the mists of time, but in neither case did I think “Gordon Bennett”. Their support has been good as well. I have been thinking about replacing the C3 with a C4, and if Minitech showed it on their website I would go straight to them, maybe a phone call is in order!!

The choice up here in Australia is a bit limited compared to what we see in England and the US. Just yesterday I had to get an MT3 Dead Centre from the local Hare and Forbes agents and it cost $42, at which point I did say “Gordon Bennett”

cheers

Bill Pudney

 

[BERTOParticipant @berto]

I’m sure Bob will have something similar !

I was going to buy an X5015M Minitech but two things stopped me :

!) It being in Queensland and i in New south wales there was no way of inspecting the machine and i will not buy anything i cannot look at !

2) Freight – these machines are heavy 380kg nett and i was expecting to pay around $200+ for freight .

I ended up with an HM-46 MILL which i could look at and pick up myself .

There is another supplier on the NSW central coast called TITAN machinery.

They sell thier own chineese imports to thier own specs although more expensive than Hare & Forbes or Minitech.

Oh and the bright green hammer finish paint has to be seen to be believed and they even paint the inside of thr T nut slots how wonderfull !

Looks like i will stick with my AL50G lathe for now at least untill i can sort out something to fix the AL320G cross slide issue or find a machine that has similar specs here in Australia with what i want !

 

IAN

[JasonBModerator @jasonb]

Does look like you are a bit limited for choice, pity as teh 280 has a 150mm x 270mm cross slide table which is a good size for bolting castings to and as the topslide can mount anywhere along it you could get a rear post on even though I’ve not found the need.

 

J

[RickParticipant @rick]

A few years ago I bought a Seig C6 lathe and X2 mill from General Tools in Adelaide Sth Australia. I fitted a belt drive on the mill and for the lathe I purchased from Little Machine Shop (US), the mill table which fits onto the cross slide. I don’t have any gripes about the Seig equipment whatsoever. Like all pieces of equipment, don’t make to do something it can’t do.

 

Rick

[SpringbokParticipant @springbok]

Hi .001

Thank you for kind remarks, could I give everyone advice from bitter experiance

NEVER NEVER purchase a lathe with a so called milling atachment with a round turret, or any other machine unless you want to do only very light work. these are similar to the Warco WMT500 and look at the Warco, Chester , Grizzle.com et all sites to see what I mean. If you are doing anything substantial it will whiplash no matter how tight the column is. I could not afford a Myford or similar bit of kit so bought a Chester626 mill have to say though it stands about 6’6″ from the ground it is a substantial bit of kit and accurate, had a few minor changes to make but on the whole great. Could not say that for the Warco needed lots of mods and adjustment though stated tested before delivery by our specialist team. HA HA.

 

Anyway food for thought for everyone as we are now lumbered with the oriental machines and only secondhand equipment of any quality but costly is now available

 

Bob

 

[BERTOParticipant @berto]

Thanks Rick i will check out those stores .

I agree that the SEIG gear is good for what you pay for it – with the exception of the super X3 as it is more expensive than my HM46 mill and not as big although variable speed and digital Z-axis readout are a bonus !

I now have 2 mills and may modify the X2 to CNC in the future but i will keep it either way as it is better suited to smaller cutters and delicate work .

The AL50G lathe has served me well although the spindle bore is annoyingly small !

Next on the list is a tool and cutter of some sort , the one in the latest AME is ripper of a copy !

 

Springbock , Did you mean round turret like the VMC or round COLUMN ?

I know the VMC has a round turret to allow it to tilt and slide is this what you had problems with ?

I was not impressed by the round column type of machine as it was a pain to raise/lower the head and even more so to change speeds although it did have 12 speeds against my machines 6.

I am thinking of a planetary gearbox to fit between the motor and the gear head to allow under/overdrive of the existing 6 speeds but that”s a long way off !

 

Regards..

IAN

 

 

 

 

[SpringbokParticipant @springbok]

Hi Ian sorry

I meant the horizontal round column I have not used the one attached to the Warco for a number of years now as the mill unit would move on anything substantial I gave up on it and pushed the mill section round out of the way A waste of money.

as far as speed is concerned I have put 3 phase

variable speed onto both my machines. This certainly makes life much easier and a lot quiter.

 

regards

 

Bob

[TerrydParticipant @terryd72465]

Hi bob,

 

I have to say that my Warco 280V has exceeded all of my expectations over the last year. The accuracy of the 3 Jaw has to be seen to be believed. It is solid, has silky smooth movement of cross slides, saddle etc and is capable of large cuts. It cuts parallel cylinders accurately and has proved to be accurate and reliable so far. Have to judge that latter though in the longer tern.

 

Perhaps I am lucky

 

Regards

 

Terry

[SpringbokParticipant @springbok]

Hi Terry

I was refering to one of the combi machines the Warco lathe itself is fine and has done excellent work. It is the mill attachment I was talking about.. At the time I was building the 7.25g Anna DAG Browns creation and some of the casting were to say the least lumpy. Have now sold the beast as was getting far to heavy to lug around.

On saying that even on small components I was makeing no matter how tight I tried to lock the column it would occasionaly drift. To my mind the pillar drill/mill/lathe was a good idea for very light work, giveing a low cost solution without haveing to purchase 2 machines.

 

 

Cheers

Bob.

[BERTOParticipant @berto]

Hi , i have finally got around to tramming the head of my new mill -same as the chester lux with dovetail column .

It seems that the y axis has a 5 thou variation from front to rear and i was wondering if anyone else has had a similar problem ?

I set up the x axis first then checked the y axis second and it seems as the column is tilting foward .

I then set up my longest parallel across the table and clockedthe top of it to see if the table was climbing or tilted but it showed no deviation .

The only other thing i could think of doing was to set up my longest engineers square on the bed and clock the top of the blade which was now in the vertical plane .

Using the spindle feed i ran the indicator up and down the blade of the square and it showed 2 thou deviation – tilting foward .

I then did the same using the column adjustment and it showed exactly the same 2 thou tiltng foward .

I would deduct from this that the column and spindle are parallel and the column is tilting foward in respect to the y axis of the table .

i set up a 2 inch square block of steel in a toolmakers vice surfaced both sides using a 75mm face mill and this also showed .0005” out of parallel indicating that the column is tilting foward .

Any thoughts on this ?

I suppose my next mission will be to lift the column from the base and see if the mating surfaces are clean and have no burrs .

Or am i creating mountains out of molehills !

 

IAN

 

 

 

[jomacParticipant @jomac]

.001 Hi Have a look at the new South bend site as they are making new model lathes and milling machines, South bend and Hercus 260 (which I have) are quality machinery, although transportation costs down here to OZ could be a bit pricey, I read some where that they are looking new outlets and suppliers.

John holloway

[RickParticipant @rick]

G’day Ian,

 

I find that the common old plumb bob gives me a good indication of Z-axis for vertical on the X2.

 

One thing to remember is that all measurements are wrong. It will never be spot on as there is always uncertainty in all the measurements you make, not only from what you are trying to achieve but in all of your measuring equipment. That is why when equipment is calibrated the result will be expressed as xxxx +/- xxxx with a confidence level of 95%. This is the way in metrology the uncertainty is expressed. So you have to decide what your error is that you are happy to live with.

 

Rick

[TerrydParticipant @terryd72465]

Posted by .001 on 20/11/2011 06:33:30:

………………………………

 

Or am i creating mountains out of molehills !

 

IAN

 

Hi Ian,

 

it depends what you want to make with your mill. For most engineering work (especially model engineering) that should be ok but if you are attempting high precision work perhaps not. It is very easy to get anal about ultra precision, there are ‘work arounds’ which can help to eliminate errors in equipment as our illustrious predecessors had to. Maudslay built an ultra precise micrometer (nicknamed ‘Lord Chancellor’) with a 16 inch screw capable of measuring to within 0.0001″ using relatively primitive equipment available then.

 

By machining both sides of your block you have doubled the error if you turned it end over end, i.e. along the axis of the bed. If you turn it across the axis of the bed the error should be eliminated if it lies in the column/bed relationship.

 

Also errors will be introduced if your block is not exactly square in cross section to begin with, or if the movable jaw of your vice can lift by a fraction of a thou or Lord Forbid, the jaws may not be perfectly vertical (even toolmakers equipment has tolerances – nothing can be perfect despite our attempts). You can even affect the accuracy by how you tighten your vice – even rigid machines will flex. There are many factors involved.

 

To summarise, look at what you want to achieve and ask ‘can I achieve that with this equipment?’ . Only you can answer that,

 

Best regards

 

Terry

 

 

[BERTOParticipant @berto]

I have now investigated the tilting column problem with my HM46 Mill .

I lifted the column off the base with an engine hoist and guess what i found !

Yes thats right dirt , grease and metal shavings all mixed together and coating the mating surfaces !

After a clean up and check for burrs and high spots it was bolted back together and to my joy the machine now trams to within .0005″ on the Y axis .

I then set up my trusty 2″ square block of scrap and faced it off and it is now machined parrallel using my 3″ face mill .

 

I will now look at something to make re-setting the head easier after it has been tilted and to help lock it better .

Tramming this was a real pain as tightening the locking nuts caused the head to move (tilt) and getting it to move .005 or less nearly impossible !

 

IAN

 

Edited By .001 on 04/12/2011 04:34:38

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