Info’ that might be of use to Warco Lathe owners.

[Bo’sunParticipant @bosun58570]

Good afternoon,

I've had my Warco WM250 for over a year now, with an outstanding warranty concern regarding "carriage lift" of around 0.018mm. Outstanding because of Warco supply issues and a domestic issue.

A 0.015mm feeler gauge inserted in the gap appeared to give satisfactory results without binding. So I set about removing the clamps to machine some material off and reduce the gap. However, all four bolts (two each side) were found loose. Simple I thought, just tighten them up, but tightening them up just locked the carriage. For the time being, I've been operating the lathe with them just tight enough to remove the lift without binding. I now have to work out a new machining regime. Seems strange to have a Gib at the rear of the carriage but nothing at the front.

Also, I found the two tailstock adjusting screws loose.

[Bo’sunParticipant @bosun58570]

Carriage lift and Tailstock loosness

[Nigel Graham 2Participant @nigelgraham2]

Well, if you go and modify any of it, you can't then fairly expect Warco to repair it under guarantee even if they are happy to extend the warranty to cover their supply problems ….

Are there no lock-nuts on the adjusting screws, or are they grub-screws?

[Bo’sunParticipant @bosun58570]

Hello Nigel,

Now that I've got a fix, I'm not going to pursue the warranty claim. That also avoids a whole lot of lifting, repacking, unpacking, more lifting and realigning.

The fixing hardware is just ordinary socket head cap screws.

[ChrisBParticipant @chrisb35596]

My WM280 had the same issue, so probably they are designed that way. I put shims under the clamp until I could feel a slight drag when sliding the carriage by hand and tightened it down.

[Bo’sunParticipant @bosun58570]

Hi ChrisB,

You maybe correct, but it would have been nice to see some reference to it in the operators handbook (or maybe not, seeing how much other useful info' has been omitted).

The design is more likely so they can produce cheaply with wide tolerances.

[SillyOldDufferModerator @sillyoldduffer]

Posted by ChrisB on 20/06/2022 18:07:09:

My WM280 had the same issue, so probably they are designed that way. I put shims under the clamp until I could feel a slight drag when sliding the carriage by hand and tightened it down.

If this is what I think it is, I don't think its a fault.

The rear of the saddle is prevented from accidental lifting off but the feature doesn't steer or contribute to the saddle's accuracy. Accuracy is provided by the polished top of the prismatic bed, on which the saddle is machined to accurately slide, not the rougher surfaces below.

Normal cutting forces don't lift the saddle off the bed, they press it down. I think reducing the gap so the saddle actually touched underneath would reduce the lathe's accuracy by nudging the machined parts of the saddle off the machined parts of the bed.

Did the gap actually cause a problem when cutting metal, or is it just a worry that it might? Not an issue on my WM280, but perhaps I don't take the sort of cuts that might lift the saddle. Such as parting off with a rear tool-post such that the cutter is pulled up rather than pushed down, maybe?

Dave

[Mick B1Participant @mickb1]

That 0,018mm 'lift' is about 7 tenths in old money.

Presumably you mean vertical play in the carriage?

I've had my WM250V for over 7 years now and never been aware of such a thing, nor given any thought to how I might measure it, what it might do, how I might fix it or whether it's worth doing so.

I can only imagine it might have some effect when there are upward forces communicating to the carriage, such as when turning in forward rotation from an RTP, or milling the underside of a component in a vertical slide – something I did successfully and AFAIK with decent precision only yesterday.

Now I don't know whether I should be worried about it.

[ChrisBParticipant @chrisb35596]

Posted by SillyOldDuffer on 20/06/2022 18:58:51:

Accuracy is provided by the polished top of the prismatic bed, on which the saddle is machined to accurately slide, not the rougher surfaces below.

Dave

Have you ever had a look at the mating vee groove in the carriage? If I had to cut it with a hacksaw I would have probably done a better job!

[Norfolk BoyParticipant @norfolkboy]

Posted by ChrisB on 20/06/2022 19:31:38:

Have you ever had a look at the mating vee groove in the carriage? If I had to cut it with a hacksaw I would have probably done a better job!

I had to smile when I read that, the vee ways on my Warco simple surface grinder are the same, look like they have been carefully scraped by an angle grinder with a masonary disc. You kind of get what you pay for I think, it's whether the sum of the frustrations defeats you in the end.

[Tony Pratt 1Participant @tonypratt1]

Do you know what, the lathes are obviously copied from European models maybe Emco & the build quality is shocking in the extreme but they do cut metal & my Warco 290V also cuts parallel.

PS my inverted vee ways are not 90 degrees so not sure where they touch each other or what the angle is meant to be, they must rely on 'point' contact only!

Tony

Edited By Tony Pratt 1 on 20/06/2022 20:54:04

[ChrisBParticipant @chrisb35596]

Don't get me wrong, I'm quite happy with my lathe. It does what I need and more. But if you look closely you'll find it's a bit roughly finished, still happy considering the price.

[Dave HalfordParticipant @davehalford22513]

Posted by SillyOldDuffer on 20/06/2022 18:58:51:

Posted by ChrisB on 20/06/2022 18:07:09:

My WM280 had the same issue, so probably they are designed that way. I put shims under the clamp until I could feel a slight drag when sliding the carriage by hand and tightened it down.

If this is what I think it is, I don't think its a fault.

The rear of the saddle is prevented from accidental lifting off but the feature doesn't steer or contribute to the saddle's accuracy. Accuracy is provided by the polished top of the prismatic bed, on which the saddle is machined to accurately slide, not the rougher surfaces below.

Normal cutting forces don't lift the saddle off the bed, they press it down. I think reducing the gap so the saddle actually touched underneath would reduce the lathe's accuracy by nudging the machined parts of the saddle off the machined parts of the bed.

Did the gap actually cause a problem when cutting metal, or is it just a worry that it might? Not an issue on my WM280, but perhaps I don't take the sort of cuts that might lift the saddle. Such as parting off with a rear tool-post such that the cutter is pulled up rather than pushed down, maybe?

Dave

That being so why do I have 15thou wear on my Rockwell Delta rear saddle clamp ?

[HopperParticipant @hopper]

Posted by Dave Halford on 21/06/2022 00:01:36:

Posted by SillyOldDuffer on 20/06/2022 18:58:51:

Posted by ChrisB on 20/06/2022 18:07:09:

My WM280 had the same issue, so probably they are designed that way. I put shims under the clamp until I could feel a slight drag when sliding the carriage by hand and tightened it down.

If this is what I think it is, I don't think its a fault.

The rear of the saddle is prevented from accidental lifting off but the feature doesn't steer or contribute to the saddle's accuracy. Accuracy is provided by the polished top of the prismatic bed, on which the saddle is machined to accurately slide, not the rougher surfaces below.

Normal cutting forces don't lift the saddle off the bed, they press it down. I think reducing the gap so the saddle actually touched underneath would reduce the lathe's accuracy by nudging the machined parts of the saddle off the machined parts of the bed.

Did the gap actually cause a problem when cutting metal, or is it just a worry that it might? Not an issue on my WM280, but perhaps I don't take the sort of cuts that might lift the saddle. Such as parting off with a rear tool-post such that the cutter is pulled up rather than pushed down, maybe?

Dave

That being so why do I have 15thou wear on my Rockwell Delta rear saddle clamp ?

Possibly from 15 thou of combined wear on the top surface of the bed and the surface of the carriage that runs on the top surface of the bed, lettting the whole carriage drop down, creating the gap on the lift plate?

Or possibly it left the factory like that? Wiith the Delta's long carriage "wings" extending forward of the toolpost it is hardly going to tilt the carriage when cutting with the topslide extended forward. Usiing a long boring bar would be about the only time any force was put on the carriage that might lift the back end of it a bit.

Or possibly from swarf ingress causing wear on the lift plate surface?

[HopperParticipant @hopper]

Posted by Bo'sun on 20/06/2022 15:56:46:

Good afternoon,

I've had my Warco WM250 for over a year now, with an outstanding warranty concern regarding "carriage lift" of around 0.018mm. Outstanding because of Warco supply issues and a domestic issue.

A 0.015mm feeler gauge inserted in the gap appeared to give satisfactory results without binding. So I set about removing the clamps to machine some material off and reduce the gap. However, all four bolts (two each side) were found loose. Simple I thought, just tighten them up, but tightening them up just locked the carriage. For the time being, I've been operating the lathe with them just tight enough to remove the lift without binding. I now have to work out a new machining regime. Seems strange to have a Gib at the rear of the carriage but nothing at the front.

Also, I found the two tailstock adjusting screws loose.

Good luck making a warranty claim on a .015mm gap there. That is about oil film thickness and will be deemed within spec. If you really want to close it up, do as you have and semi-tighten the bolts. Even better, cut a piece of shim of the correct thickness and put between the catch plate and carriage. A piece of .02mm shim should do the job. A piece of paper cut like a gasket might even do the job. But you then have to be sure that the bed surface is runs on is perfectly parallel to the top surface the carriage sits on, otherwise you will get binding at one end of the bed or the other.

It's unlikely to affect the performance of your lathe terribly except when the topslide is advanced so the tool bit is beyond the leading edge of the carriage, or when a boring bar is stuck out the front of the carriage. Possibly when taking interrupted cuts too. If using a rear parting tool, you should have the carriage locked anyway.

Edited By Hopper on 21/06/2022 04:08:19

[SillyOldDufferModerator @sillyoldduffer]

Posted by ChrisB on 20/06/2022 22:01:16:

Don't get me wrong, I'm quite happy with my lathe. It does what I need and more. But if you look closely you'll find it's a bit roughly finished, still happy considering the price.

Not necessary to look closely – they are roughly finished! But they're a modern design, and although clearly made-down to a price, they're generally good enough where it matters.

One of my old books, aimed at industrial purchasers before 1930, is highly critical of a British bad attitude to machine tools generally. Old-fashioned, out-of-date, conservative firms assumed best buy lathes were heavy old-fashioned manual lathes expected to last 60 years or more. Well-finished, beautifully made, hideously expensive, required highly paid skilled operators, and had to be ordered 6 to 12 month in advance. For this the owner got a wonderful machine and low-productivity, unable to compete with firms who had modernised at home or abroad. The book advises buying machine-tools designed to work hard for up to a maximum of ten years, then replacing them with whatever was best at the time: capstan lathes, then mechanical and hydraulic automatics, through Numerical Control, CNC, CAM, and multi-axis machine centres.

The Myford ML7 is a good lathe, but it can be criticised on cost-grounds. Several features could be simplified, and money could be saved by not bothering with the finish, as was done to British lathes made during WW2 – spartan, but fully functional, made to do a job of work, and paying no attention to pride of ownership. Far Eastern hobby lathes are in the Spartan camp – aggressively priced to suit Model Engineer's notorious for not spending money! The machines work reasonably well and the price point make them attractive compared with better finished, but costly western alternatives.

Much criticism of Far Eastern gear is based on look and feel rather than how well they cut metal. Comparing cylinders turned on various lathes In a double-blind test, I don't think it would be possible to identify which lathe produced which cylinder. However, in hobby workshops, the output often isn't the be all and end all! The owner may well have other goals. Good-looking smooth sliding tools increase confidence, productivity and pleasure, especially if you like everything to be 'just so'. In contrast, I don't care much about warts provided equipment does what I need, or as Chris puts it keeps me 'happy about the price'. Others, more power to their elbows, are sensitive to finish and seek perfection in their machines. Some folk worry about having their kit painted the correct colour: not me!

Main thing is to enjoy the hobby, however it takes you!

Dave

[HopperParticipant @hopper]

Posted by SillyOldDuffer on 21/06/2022 08:49:22:

…

The Myford ML7 is a good lathe, but it can be criticised on cost-grounds.

…

It certainly can be, but it must be remembered it was developed and sold as a low-cost hobby lathe. It was quite a few pounds cheaper than the Drummond/Myford M-Type that it replaced as the Model-Engineer's favourite and massively cheaper in later years than rivals such as Boxford and Raglan. .

[Dave HalfordParticipant @davehalford22513]

Posted by Hopper on 21/06/2022 03:36:59:

Posted by Dave Halford on 21/06/2022 00:01:36:

Posted by SillyOldDuffer on 20/06/2022 18:58:51:

Posted by ChrisB on 20/06/2022 18:07:09:

My WM280 had the same issue, so probably they are designed that way. I put shims under the clamp until I could feel a slight drag when sliding the carriage by hand and tightened it down.

If this is what I think it is, I don't think its a fault.

The rear of the saddle is prevented from accidental lifting off but the feature doesn't steer or contribute to the saddle's accuracy. Accuracy is provided by the polished top of the prismatic bed, on which the saddle is machined to accurately slide, not the rougher surfaces below.

Normal cutting forces don't lift the saddle off the bed, they press it down. I think reducing the gap so the saddle actually touched underneath would reduce the lathe's accuracy by nudging the machined parts of the saddle off the machined parts of the bed.

Did the gap actually cause a problem when cutting metal, or is it just a worry that it might? Not an issue on my WM280, but perhaps I don't take the sort of cuts that might lift the saddle. Such as parting off with a rear tool-post such that the cutter is pulled up rather than pushed down, maybe?

Dave

That being so why do I have 15thou wear on my Rockwell Delta rear saddle clamp ?

Possibly from 15 thou of combined wear on the top surface of the bed and the surface of the carriage that runs on the top surface of the bed, lettting the whole carriage drop down, creating the gap on the lift plate?

Or possibly it left the factory like that? Wiith the Delta's long carriage "wings" extending forward of the toolpost it is hardly going to tilt the carriage when cutting with the topslide extended forward. Usiing a long boring bar would be about the only time any force was put on the carriage that might lift the back end of it a bit.

Or possibly from swarf ingress causing wear on the lift plate surface?

Might I suggest that it's more about controlling the weight of the apron, which pivots about the front of the bed. The only thing that stops this is the apron power shaft/shafts, which will be subject to unnecessary wear without the rear 'clamp'.

I don't believe that in todays constant drive to remove cost it would still exist if it didn't do something, just because some europeans put it there back in the day the design was copied.

[Clive Brown 1Participant @clivebrown1]

+1 that a carriage lift of 0.018mm is not really significant, but I wonder if the quoted measurements are wrong. Th OP refers to using a feeler gauge of 0.015mm inthe gap. If such a thing exists, I've never seen one.

[Bo’sunParticipant @bosun58570]

From OP,

Oops, should have read 0.18mm. Thanks for your observation Clive.

Yes, I agree with other posters that 0.018mm is insignificant.

However, I am concerned about finding loose screws.

[HopperParticipant @hopper]

So put some shim under the plate and tighten the bolts and it shold be ok.

[ChrisBParticipant @chrisb35596]

Posted by Bo'sun on 21/06/2022 11:49:38:

From OP,

Oops, should have read 0.18mm. Thanks for your observation Clive.

Yes, I agree with other posters that 0.018mm is insignificant.

However, I am concerned about finding loose screws.

My understanding is the screws are loose on purpose, just to take up the slack. I only noticed they were loose when I had to take the carriage apart due to a crash. Didn't think much of it at that time, thought they must have come loose during use, but tightening them down during assembly the carriage got stuck. So I reasoned the clamp should have been shimmed, and that's what I did. Probably it was not necessary as some have commented.

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