chinese lathe

[Julian NewsteadParticipant @juliannewstead62906]

apron to bed

[Julian NewsteadParticipant @juliannewstead62906]

is this how the apron should sit on bed. the right one looks ok but left seems in wrong place. any help please

[Ian ParkinParticipant @ianparkin39383]

I’m sure that it looks ok your tailstock locates on the left hand “v”

[OldironParticipant @oldiron]

At a guess I would say that the cross slide is using one trapezoidal way and one flat way. The tailstock will use the other pair of ways. The fact that that configuration has the way wipers points me in this direction.

BTW the apron is the bit with all the levers and knobs that hangs down the front of the lathe.

regards

Edited By Oldiron on 13/03/2021 17:09:53

[David George 1Participant @davidgeorge1]

Hi Julian welcome to the forum. The side nearest to the operator should run on the inverted V rail and the far side shoukd just run on the flat surface both with a plate to hold down the saddle casting. The tailstock runs on the rear V rail and front flat surface with a clamp plate central to hold it down and clamp down.

David

[Howard LewisParticipant @howardlewis46836]

On my mini lathe, and my big one (12" swing over bed Warco BH600 / Chester Craftsman lookalike ) that is how the Saddle and Tailstock locate.

Saddle locates on Front prismatic way and sits on Rear flat way.

Tailstock locates on Rear prismatic way and sits on Fronf flat way.

Looks as if you have a wiper missing from the Prismatic side of the Saddle.

Possibly Warco or Chester Hobbystore can provide replacement?

Howard

[Steve NeighbourParticipant @steveneighbour43428]

Posted by Howard Lewis on 13/03/2021 17:23:50:

On my mini lathe, and my big one (12" swing over bed Warco BH600 / Chester Craftsman lookalike ) that is how the Saddle and Tailstock locate.

Saddle locates on Front prismatic way and sits on Rear flat way.

Tailstock locates on Rear prismatic way and sits on Fronf flat way.

Looks as if you have a wiper missing from the Prismatic side of the Saddle.

Possibly Warco or Chester Hobbystore can provide replacement?

Howard

Just looked at my own Warco WM250 (made in the Weiss factory in Shenzen, China) and the carriage locates exactly as the above members have described, so yours is correct

Re missing bedway wiper, you need to rectify that asap or swaf will get inbetween the carriage and bed and cause damage – you can make your own bed wipers easily, just get hold of some 3-4mm dense felt

[Oily RagParticipant @oilyrag]

How weird!

The South Bend 9" uses 3 prismatic ways with just one front inner flatway for the tailstock (the inner rear prismatic way being the other tailstock locator). Hence the saddle runs on the outer prismatic ways fore and aft. Its noticeable that this gives good resistance to 'skewing' of the saddle when reversing the saddle. I assume the Boxford being a clone of the SB is similar.

The Emco Maximat Super 11 uses a similar bed form to this Chinese lathe. But the front Prismatic is a substantial height and width whereas the rear inner prismatic is quite small and performs the tailstock location guide. I wonder if the Chinese / East Germans / Russians copied the Emco style bed?

Martin

[Tim StevensParticipant @timstevens64731]

Can we be sure it isn't a Colchester clone?

Tim

[Oily RagParticipant @oilyrag]

Tim,

Quite possible! Its about 20 years since I studied a Colchester, but I take your point. Maybe even that Emco copied the Colchester bed form.

I find the differing designs of Machine Tools are of interest. One such is the 'continental' style of millers, especially the universals, where the 'Y' axis is not performed by an elevating knee but by the ram head moving fore and aft. This allows the 'knee' to carry a platen to which a swivelling, and sometimes tilting, table is attached. Examples being the Deckel, Thiel, Schaublin, and Aciera as well as many clones. I'm surprised that there are no British (with the exception of the GH Alexander 'Toolmaker' ) or American versions (with the exception of the Brown & Sharpe 'Omniversal' ) of this form. Even more surprised the Chinese haven't cottoned on to this yet – probably a route for an upgrade in the future? Having said that I did see a Deckel clone in China made by the 'Beijing Instrument M/c Tool works' but they were, I was told at the time, very rare!

Martin

Edited to get rid of the gormless emoji!

Edited By Oily Rag on 13/03/2021 19:09:57

[LathejackParticipant @lathejack]

The Chinese lathe bed and saddle in the photo looks like it could be one of the 180 or 210 lathes, so 7 or 8 inch swing with 13,14 or 16 inches between centres.

It is certainly sat correctly. The underside of the saddle has a V way cast into it on the left side of the image which has plenty of clearance around the tailstock V guidway formed on the bed to ensure it does not touch it, as well as clearance over the flat tailstock guidway on the right, and so only contacts the V guide on the far right and the flat guidway on the far left of the image. This is typical of lathes with these type of bedways.

Edited By Lathejack on 13/03/2021 19:25:05

Edited By Lathejack on 13/03/2021 19:28:41

Edited By Lathejack on 13/03/2021 19:30:43

[Dave HalfordParticipant @davehalford22513]

Julian,

Don't worry, it will only go together one way.

[LathejackParticipant @lathejack]

Posted by Oily Rag on 13/03/2021 18:18:26:

How weird!

The South Bend 9" uses 3 prismatic ways with just one front inner flatway for the tailstock (the inner rear prismatic way being the other tailstock locator). Hence the saddle runs on the outer prismatic ways fore and aft. Its noticeable that this gives good resistance to 'skewing' of the saddle when reversing the saddle. I assume the Boxford being a clone of the SB is similar.

The Emco Maximat Super 11 uses a similar bed form to this Chinese lathe. But the front Prismatic is a substantial height and width whereas the rear inner prismatic is quite small and performs the tailstock location guide. I wonder if the Chinese / East Germans / Russians copied the Emco style bed?

Martin

The old Boxford Southbend clone lathes do indeed use a triple V bedway, with two V ways guiding the saddle, but the Smart and Brown Sable which is also based on the Southbend lathe abandoned the third V way and reverted back to a single V and a flat way to guide its saddle.

There were also some very nice Taiwanese made lathes of 5 1/2, 6 and 6 1/2 inch centre height produced in the 1970's and 80's that had beds with triple V ways. Some of these were badged as Lam and Lantaine, Warco used to offer it as the 300B or B300 I think in the 1980's and these lathes were higher quality Taiwanese made versions of the more recent Chinese made Warco BH600 and Chester Craftsman machines which have sadly lost the third V way.

 The current Southbend branded lathes made in the Far East and sold by Grizzly Machine Tools in the USA use a triple V bed, including the new SB Heavy 10 model which is actually a copy of the earlier Emco Super 11.

Most Emco lathes, such as the Compact 8 and the Super 11, used a bed with a tiny tailstock V way, but with a buttress type V way at the front to guide the saddle. The buttress V way is tilted over so the wide outer flank has a shallow angle, but the rather narrow inner flank is at a much steeper angle than a standard V in an attempt to better absorb side thrust from cutting forces. The Far Eastern made copies of the Emco Compact 8, known as the 918 and 920, still use the very small Emco style V way for the tailstock, but reverted back to a standard V guide with equal angled flanks at the front of the bed to guide the saddle.

 

 

 

 

Edited By Lathejack on 13/03/2021 20:57:18

Edited By Lathejack on 13/03/2021 21:07:06

Edited By Lathejack on 13/03/2021 21:10:30

[Julian NewsteadParticipant @juliannewstead62906]

Thanks for all the help people

[Julian NewsteadParticipant @juliannewstead62906]

The reason for asking question is I have adjusted the plates on saddle there good but I can twist saddle from left to right it is a bit hard to explain. Hope you can understand

[Dave HalfordParticipant @davehalford22513]

The rear gib plate should stop the saddle lifting at the rear. The front one is normally part of the saddle lock.

With these adjusted properly the saddle should not be able to lift and twist on the ways. Could you have mixed up the gib plates?

[HopperParticipant @hopper]

Some of those Chinese lathes have a rather dicky adjusting system on those two lift plates, aka gib plates, that can need careful adjustment. There are typically two bolts that clamp the plate down and two others that work against them to stop the plate clamping down all the way solid. The two latter screws have to be adjusted so when tightening the two clamping screws down, you end up with about one thou clearance which will stop excess movement. A better fix can be to eliminate the extra two adjusting screws and set the plates to the correct position using shims.

Otherwise, the saddle should be sitting down on the inverted V and should not be able to pivot. If it can, somehting is stopping it sitting down firmly. Look for grit, swarf, burrs or even the way wipers stopping full contact between saddle and V way.

YOu could put a thin smear of bearing blue on the lathe bed and rub the saddle back and forth a couple times to get a reading on where the two parts are contacting. Should be along the full length and width of  both the flanks of the V way.

Edited By Hopper on 14/03/2021 10:13:33

[BazyleParticipant @bazyle]

I think the skewing is either bad wear or some swarf under the saddle, perhaps due to lost wiper. Is the flat way next to the V side showing any sign of contact? A bit of swarf here lifting the saddle will prevent contact with the V.
You said above "plates" there will be one underneath at the rear, but where else?

[Howard LewisParticipant @howardlewis46836]

The plates should be adjusted so that the Saddle moves freely, but without slack. I E only just enough for a running clearance.

As soon as the Saddle is clamped to the bed, it should be pulled down onto the prismatic way, for a positive location.

In a similar way, when the Tailstock is clamped, it will be pulled down and accurately located.

Howard

[Dave HalfordParticipant @davehalford22513]

Posted by Bazyle on 14/03/2021 10:11:24:

I think the skewing is either bad wear or some swarf under the saddle, perhaps due to lost wiper. Is the flat way next to the V side showing any sign of contact? A bit of swarf here lifting the saddle will prevent contact with the V.
You said above "plates" there will be one underneath at the rear, but where else?

If you look at the OP picture, you can see two gibs front and back beneath the saddle, they are quite chunky. The front one seems to be marking (different colour band) what might be the top of the rack mounting. So maybe it's keeping the saddle from seating on the front way.

[HopperParticipant @hopper]

Posted by Dave Halford on 14/03/2021 10:51:32:

Posted by Bazyle on 14/03/2021 10:11:24:

I think the skewing is either bad wear or some swarf under the saddle, perhaps due to lost wiper. Is the flat way next to the V side showing any sign of contact? A bit of swarf here lifting the saddle will prevent contact with the V.
You said above "plates" there will be one underneath at the rear, but where else?

If you look at the OP picture, you can see two gibs front and back beneath the saddle, they are quite chunky. The front one seems to be marking (different colour band) what might be the top of the rack mounting. So maybe it's keeping the saddle from seating on the front way.

Well spotted! It certainly does look in the picture like the gib plate there is dragging on the bed and would wuoild be lifting up the saddle in the process. Looks like the gib is too thick for that space available.

[Dave HalfordParticipant @davehalford22513]

Julian,

Is this a brand new lathe or a nearly new secondhand one that has been passed on and suspiciously not had much use?

[JourneymanParticipant @journeyman]

Posted by Dave Halford on 14/03/2021 10:51:32:

If you look at the OP picture, you can see two gibs front and back beneath the saddle, they are quite chunky. The front one seems to be marking (different colour band) what might be the top of the rack mounting. So maybe it's keeping the saddle from seating on the front way.

Not convinced, believe might be a perspective error, my interpretation:-

1. Rear flat that saddle runs on
2. Small prismatic way for tailstock
3. Front flat for tailstock
4. Large prismatic way for saddle
5. Front gib strip
6. Leadscrew cover or chip tray

I could of course be seeing things

John

[Dave HalfordParticipant @davehalford22513]

Julian will hopefully come back and enlighten us.

I don't like the way the rear gib strip sticks out from underneath the saddle

[Howard LewisParticipant @howardlewis46836]

Could it be that the gibs have been incorrectly replaced in the wrong places? (ie Front should be where the Back is, and vice versa? )

Changing over might improve the ability to adjust.

Howard

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