Warco GH1330 Advice

[John Hartley 2Participant @johnhartley2]

Hey everyone.

I am looking for some advice i have a old Warco GH1330 and looking to eliminate a few problems.

Problem 1 is the amount of backlash i have

Problem 2 is the head stock is not straight so when it's running and you do a pass it comes out tapered.

I am a full beginner and any advice would be greatly received

[John Hartley 2Participant @johnhartley2]

Advice and help.

[Thor 🇳🇴Participant @thor]

Hi John,

Welcome to the forum. I assume you are familiar with Rollie Dad's method so you know the headstock isn't aligned with the bedways. If the headstock is misaligned there may be some screws that can be adjusted, although I haven't seen a misaligned headstock on a prismatic bed lathe.

Thor

[BazyleParticipant @bazyle]

That is quite a big and dangerous lathe for a complete beginner. Owing to the design it is almost certain that the headstock is aligned but the tailstock is a bit off, see Thor's advice above.
Backlash is normal so learn to live with it though there are sometimes adjustments that are slack not associated with wear in the parts, When it gets to be half a turn of the handle it might be a problem.

Keep reading this forum and use the search facility as there is a lot of advice for beginners and many times good instructional books have been listed. Books tend to be more reliable than Youtube videos which are often made by people with almost no brains. There are some threads on here listing better videos (and still some crap ones).

[SillyOldDufferModerator @sillyoldduffer]

Welcome John,

I'm not a GH owner myself so lets hope one turns up soon who knows exactly how your machine is adjusted.

Backlash where and how much?

• Because most lathe cuts only go in one direction, backlash rarely matters much unless the operator forgets to compensate for it.
• As backlash on the cross-slide is most annoying, most lathes provide some more-or-less crude adjustment system. A mini-lathe has three screws on the saddle top that allow the nut to be tilted to take up slack on the worm underneath. My lathe has a slot cut in the nut allowing a screw to bend the nut slightly so the threads grip more tightly. I expect yours is similar and can be sussed out if no-one gives an accurate answer.
• Beware! Frequent over enthusiastic backlash elimination causes severe wear and it's not unusual for previous owners to quickly wear the thread enough to require a new nut. New worm too if you're unlucky! But it''s annoying rather than fatal!

Taper cutting with the tailstock or not?

• With a tailstock holding the end most likely reason for taper cutting is the tailstock is out of line; they're adjustable because of the need to cut deliberate tapers and can move in normal service, or when the lathe is shifted to a new home. Various mechanisms found on tailstocks, such as a pair of opposing bolts that are turned differentially to slant the top part of the tailstock.
• Taper cutting without the tailstock:
  • The workpiece is too long and bends under cutting pressure causing a light cut at the floating end, cutting deeper approaching the chuck. Support the job with a tailstock or steady
  • The head is misaligned – unlikely on a prismatic bed lathe
  • The lathe bed is twisted. As this is a new installation, is the floor under the stand uneven, or the stand itself wonky? If they're OK, it may be necessary to shim or adjust the lathe's feet straighten the bed. (Lathe beds look strong but twist quite easily.) Thor has already mentioned Rollies Dad!

I advise taking diagnosis slow and steady – don't rush into doing anything dramatic until you've got a fairly good feel for the lathe overall. Quite often two or three clues from different jobs are needed to identify a problem and premature disassembly is an excellent way of adding confusing new faults. You can guess how I know!

Dave

[peak4Participant @peak4]

Hello and Welcome to a friendly and helpful forum; whereabouts in the world are you?
If you're in easy distance of Buxton Derbyshire, you're welcome to a brew.

Please tell folk here exactly what you are turning, and how, which should enable better assistance.

I struggled to find a decent manual for my early Warco GH1330, which is primarily imperial, but found that, since they are pretty generic, the Grizzly one is good
https://cdn0.grizzly.com/manuals/g0782_m.pdf

Bill

[Tony Pratt 1Participant @tonypratt1]

Hell that is a big lathe for a beginner! All I can say is be careful, don't wear gloves of any kind [some people use vinyl or latex but I haven't used anything whilst operating machines in over 40 years of machining] and wear safety glasses at all times.

Tony

[Howard LewisParticipant @howardlewis46836]

Welcome to the Forum.

As a "Full beginner", you have a large, and fairly complicated (By Model Engineering standards ) machine,

Before you start tinkering with the machine, buy and read a book or two on lathes.

The practice that you MUST follow id "If it ain't broke; don't fix it" Adjusting without really knowing what you are doing, and being able to measure it, can spoil an otherwise perfectly good machine.

You need to learn how to operate and to check the machine before making ANY adjustments. Rushing in, you might do more harm than good (IT has been known to happen ).

IF you really believe that the Headfstock is out of align, to check it you need to buy or make an Alignment Bar.

You will also need have a Dial Test Indicator and a Magnetic base on which to mount it.

For a start, find and join a Model Engineering Club. There you can obtain face to face advice, and probably demonstration and physical help..

Wheraboiuts are you located?

Don't make a big thing out of backlash. 0.020" in Leadscrews is not unknown and does not make a machine inoperable, by any means.

Without some backlash / clearances the machine could not operate, but would be locked solid.

As an example,when you clamp the Tailstock, you are taking up all the clearance between the Tailstock and the bedways!

DON'T think that a self centering chuck will hold work absolutely concentric. When you know what parts are in the chuck, you will realise that the many clearances make this impossible. A good 3 jaw will hold within 0.003".

I have known a worn one with 0.035" eccentricity, and still capable of turning out good work in the right hands.

How to check the machine, using the DTI, you need to read books such as L H Sparey "The Amateur's lathe", I an Bradley "The Amateur's Workshop", Stan Bray "Lathework", or Harold Hall "Lathework", or Neil Wyatt's book on using a lathe.

Check things carefully and in a logical sequence. If you are not sure of what you are about to do DON'T

Get advice and preferably face to face help

Howard

[HopperParticipant @hopper]

The Myford ML7 Users Manual that is available free on the net as a PDF if you google it, contains a good section on a simple way to set your lathe to turn parallel by "twisting" the bed using shims under the feet at the tailstock end. (This is for turning without a tailstock centre in use of course, as SOD described above.) You do it by turning a test piece of scrap bar and measuring it with a standard micrometer. So no fancy levels, dial indicators, test bars etc needed.

As far as a general "how to" book, Neil Wyatt's book from ArcEurotrade would be more relevant to your modern Warco than the classic texts by Sparey et al. that are more Myford oriented.

Edited By Hopper on 16/08/2022 09:34:45

[Howard LewisParticipant @howardlewis46836]

Your lathe may be turning a taper because it is clamped down in such a way that the bed is twisted.

It is an expensive and sophisticated machine, so it well worth spending time and effort to set it up properly.

The time spent will be pay dividends for the rest of the time that you have the lathe..

If the bed is twisted, the lathe never will turn parallel, so this is the first thing to check and correct.

The method is is explained on pages 27 and 28 of Ian Bradley's "The Amateur's Workshop", in the Myford Series 7 manual (Also by Ian Bradley ) and in other books, ,being known as "Rollie's Dad's Method"

At this stage, this does not involve the Tailstock, .

Once any twist has been removed from the bed , THEN you can start checking Headstock alignment, IF it needs it. Probably not.

Once the lathe is "levelled" and capable of turning parallel any sturdy piece of metal (1" diameter NOT slender )

Slender material will bend away from the tool, especially if the tool is not sharp (High Speed Steel, NOT carbide tipped, because ordinary, moulded carbide tips are not sharp! ) or is not mounted on centre height.

You can tell if the tool is on centre height.

If it is not, it will, leave a "pip" in the middle of the work. The diameter of the nip will show how how far off centre the tool is.

Correct this, by shimming the tool (Add shims under the tool if it is low, remove if it is high ) before dong anything else. Biscuit tins, or other tin cans,( NOT corrugated ones! ) are about 0.010" thick.

Once the tool is at centre height, you can, if you still need to check Headstock alignment , use an Alignment Bar.

This will have a Morse Taper. The female taper in the spindle is 5 MT, so you will, need a 5-3 MT reducing sleeve (One would have been supplied with the lathe originally )

Do NOT grip the bar in a chuck, either 3 or 4 ,jaw, The jaws may not hold work on the axis of the lathe.

(This may not matter for normal turning work, since the surface produced will clean up and be parallel to the lathe axis, in the same way that the eccentricity from a 3 jaw chuck will be taken out by any cut which exceeds the eccentricity ). But don't worry about that now!..

Make sure that all the tapers are clean and undamaged. If any burrs are present, gently remove them with a stone or diamond file Diamond files will remove metal VERY rapidly, so take only a few strokes before checking.

Once the Alignment Bar is in place, a D T I, mounted on the Saddle, at centre height, can be used to check for alignment. You will need a DTI, and some means of mounting it on the Saddle. Often the method used is to mount on a Magnetic base.

You will need these things when mounting work in the 4 Jaw chuck, in the future, anyway.

The Headstock is unlikely to be out of line.

IF it is, try to obtain skilled help to correct it. Get it wrong, and you might make the machine worse, and worthless!

If you cannot buy or borrow an Alignment Bar, you can make your own. If you want to do this, PM, and I will explain how to go about it. Obviously the work needs to be precise.

Again, this where being a member of a M E Society will help by hopefully finding someone prepared to help you.

Once you are happy with things, THEN, you can check Tailstock alignment, BETWEEN centres.

The taistock centre should be the hardened one, and undamaged,.

The centre for the Headstock will be the soft one. The first job is to offset the Top Slide by 30 mdegrees and take a very light skim off it, to clean it up. Once this is done, leave it in the Headstock, and mount your Alignment Bar between centtres and check, with the DTI mounted on the Saddle check Tailstock alignment.

If the Tailstock is misaligned, use the two adjusting screws to rest until the DTI reads Zero at both ends of the bar.

Again, if you are unsure; get skilled help.

If you say where you are, if you cannot get help from a local club member, it might be that some one on here might be be close enough, and prepared come an help and advise you.

HTH

Howard

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