Warco 250 cross slide dial slipping

[JasonBModerator @jasonb]

Good to know my fix worked, just make sure the screw does not start to bind as you wind the cross slide back towards you, I have heard it said that is why they are not always tightened at the factory.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by JasonB on 04/11/2015 07:06:46:

…. just make sure the screw does not start to bind as you wind the cross slide back towards you, I have heard it said that is why they are not always tightened at the factory.

.

So …

Would that factory be in the same group as the [now infamous] 'Optimum' one ?

and; what are we to make of Warco's proud claim [ see page_1] ?

MichaelG.

[JasonBModerator @jasonb]

That type of lathe comes in many colours not just Warco green so the loose nut could apply to one of many suppliers I was not infering that the Warco ones are any looser or tighter than others.

The test certificates do not cover backlash but you would have thought if tested here they should not be sent out with that amount of play.

Edited By JasonB on 04/11/2015 07:54:39

[Neil WyattModerator @neilwyatt]

My I respectfully suggest that people don't rush into suggesting people return lathes BEFORE adjustments that can reasonably be checked by the user are done.

It would have been very unfair if the lathe had gone back to Warco for want of tightening one screw, yet that was suggested.

As for the issue in the other thread, I have suggested that no measurements are taken as meaningful until the adjustment of the spindle bearings is checked.

Neil

[mechman48Participant @mechman48]

Roger

I don't have manual as pdf but will attempt to scan & save as then forward if you can wait a while, just for curiosity did you not get a manual supplied with your machine?

George.

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Neil Wyatt on 04/11/2015 08:44:18:

My I respectfully suggest that people don't rush into suggesting people return lathes BEFORE adjustments that can reasonably be checked by the user are done.

It would have been very unfair if the lathe had gone back to Warco for want of tightening one screw, yet that was suggested.

Agreed, although it's a shame that Mr. Warren doesn't take a leaf out of Ketan's book and help his customers on this forum.

Russell.

[Roger HeadParticipant @rogerhead16992]

George

Thanks very much for your kind offer, but I don't want to put you to any trouble at all. I'll explain; I don't have one of these (Warco 250) machines. I'm in Oz, where I have one of the fairly generic Chinese 13×40 lathes. It's a good machine, really good at the engineering level, but utter crap at the cosmetic level, and the manual that came with it looks like a kid's freehand sketchbook – truly! I saw the page that you posted and I recognized the (generic!) leadscrew and nut arrangement that is the same as mine, but in a respectable drawing. I'll continue with that further below, but I thought that if you had a pdf manual with all drawings of a similar quality, I might be able to relate some of my 'sketches' and perhaps glean a better understanding of what is being portrayed in my manual. So please, don't put yourself out, George. Thanks for replying.

Jason

Your immediate hit on the nut mounting screw suggested to me that you have perhaps had one of this style of cross-slide apart at some time, or at least know the intended method of operation of the nut (44), the mounting screw (28), and the collar (29). I am stumped when it comes to understanding the purpose of the collar. I hope that you can enlighten me.

Thanks, Roger

[JasonBModerator @jasonb]

Roger, Yes and No!

I have had the cross slide apart on my 280 but it does not have that collar (29) so can't help with what it might do.

This is my parts diagram, what it does show is the two slotted head grub screws that provide adjustment of the nut you spreading the cut and taking up backlash.

Have you had a look on Grizzley's site to see if they have a similar lateh to yours as the manuals are all there to download and better than most.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Roger Head on 04/11/2015 14:11:54:

… the mounting screw (28), and the collar (29). I am stumped when it comes to understanding the purpose of the collar.

.

Roger,

I think that (29) is probably just a heavy-duty washer, to spread the load of tightening (28) against cast iron.

MichaelG.

[mechman48Participant @mechman48]

Roger / anyone else

I have scanned my manual into pdf doc folder so if you need a copy or any particular page feel free to drop me a pm. Please bear in mind my machine / manual is circa 2012, so there may / will be updates in newer machines / manuals that may differ from the version I / you have so I cannot make any claims or guarantee that my manual will meet / suit your particular machine / needs, just purely as a ref doc.

George.

[Roger HeadParticipant @rogerhead16992]

George, Michael, Jason,

I've got it figured (I think). Story and sketches tomorrow if I can.

Life would be so much easier with accurate drawings… sigh.

Roger

[Roger HeadParticipant @rogerhead16992]

This is how I think the cross slide nut is mounted in my Hafco AL340D (generic Chinese 13×40, similar to Grizzly g0782, etc), and, by extension various other brands/models. In my 'Cross Slides' album there are pages from the manuals for three different lathes, all similar, but not identical. Two of them (the Warco 250 and the Grizzly g0782) are functionally identical. The third, (Warco 280) appears to omit the collar around the nut mounting screw. It may well be correct, although I would be surprised, because it would mean that the nut placement would be even more critical.
How it works: The image 'xslide nut.jpg' shows the arrangement in my lathe. The collar in the parts diagram doesn't truly illustrate the shape (sort-of an inverted top-hat), and that makes it hard to vizualize how it works. The collar is a very neat fit (< 0.001"?) in the counter-bored hole through the cross slide, and the bottom half (the smaller diameter section) is minutely (~0.001"?) longer than the thickness of the section of the slide through which it goes. The result is that when the bolt is inserted and locked down into the nut, it (the nut, bolt, and collar assembly) is held to the cross slide but is free to rotate about the vertical axis. This is good from the point of view of coping with a slight bend in the leadscrew (in the horizontal plane, although it doesn't handle it very well in the vertical plane), but in itself it isn't sufficient. The reason why is because the position in the horizontal plane of the leadscrew front bearing is invariably not exactly in line with the nut position on the cross slide. This condition is catered for by making the hole through the collar larger than the diameter of the bolt, so so that the nut (and, of course, the bolt) can be positioned off-centre before being locked to the collar. That adjustment is made with the cross slide fully retracted i.e. with the nut as close to the leadscrew front bearing as possible.
It certainly works very well on my lathe. The collar is 20mm diameter and the M8 bolt has ~1.1mm of movement available within the collar. Movement of the collar in its recess isn't visible to the naked eye, but the change in light reflection from an oil meniscus at the joint can be seen when changing cross slide direction. It's a feather-light movement.

Looking at the WM250 image it looks like the lower half of the collar that I have illustrated is actually formed as part of the leadscrew nut, and I assume the collar is basically a cup shape. It would all work in exactly the same manner, but it seems an odd way to make the nut. Edit: Not quite the same; the collar part formed on top of the nut would need to hug the bolt and have the movement clearance on its outer diameter. [/edit]

If the WM280 image is correct, it would seem that there is virtually no tolerance for misalignment or distortion of the leadscrew. Maybe the parts diagram is incomplete, and it is in fact similar to the above?

 

Edited By Roger Head on 06/11/2015 07:55:01

[JasonBModerator @jasonb]

The 280 is as built as I have had mine apart.

If that collar was bored eccentrically it would allow a bit of sideways adjustment to line the screw up, similarly if the collar stops the nut butting tight to the underside of the cross slide that would allow it to float vertically to allow for any out of line parts, all the thrust being taken by the spigot on the nut

[Roger HeadParticipant @rogerhead16992]

Hi Jason, thanks for the Grizzly pointer.

'If that collar was bored eccentrically …' Umm, yes, but then you would need some way of holding the rotational position while tightening the bolt – maybe a pin spanner?

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