Good Quality Small Lathe

[CotswoldsPhilParticipant @cotswoldsphil]

Hi Michael, you beat me thanks.

Hi Andrew, This photo of the back of the saddle from the chuck end indicates the gap(s) I'm interested in. Both sides of the saddle.

Note this only applies for narrow-guide Super 7 machines before S No. SK1088913

Anyone else willing to provide the measurements would be most appreciated.

It might be interesting to have some ML7 gaps as well.

Regards

Phil H

[Neil WyattModerator @neilwyatt]

This may interest anyone who wants to follow up lathe accuracy issues.

1996 text, but appears to be the full book.

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Neil Wyatt on 03/02/2015 15:00:07:

This may interest anyone who wants to follow up lathe accuracy issues.

1996 text, but appears to be the full book.

Neil

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Good find, Neil … But they do say it's only a preview and pages will be limited.

MichaelG.

[Neil WyattModerator @neilwyatt]

It did show me a lot of pages, I had searched for 'narrow guide principle' as I was curious why what can be a problematic feature gets used – it's to stop the slide jamming, which appears to be over-conservative for the width to length ratio of most lathes.

Neil

[andrew winksParticipant @andrewwinks64215]

Ahhh….I see it all !

I'll check this machine when I'm done with my day job and report back.

I guess that's why vee beds were invented?

Andrew

[andrew winksParticipant @andrewwinks64215]

Interesting.

Michael, try hitting "cntrl F" , enter Narrow Guide Principle and it will highlight some pages that are readable.

Annoying that the book is not available as ebook, yet google puts these up as a teaser.

Andrew

[Neil WyattModerator @neilwyatt]

V-beds count as narrow guides. They have the advantage of providing positive location (under normal cutting forces) on their own.

You can buy the ebook – for £70!

Neil

Edited By Neil Wyatt on 03/02/2015 21:21:53

[andrew winksParticipant @andrewwinks64215]

mmm… 70 converts to too many AUD for my liking! Cuts into my MEA (Model Engineering Allowance) I'll be content with the snippets.

Andrew

[Michael GilliganParticipant @michaelgilligan61133]

Posted by andrew winks on 03/02/2015 20:38:19:

Annoying that the book is not available as ebook, yet google puts these up as a teaser.

.

Andrew,

There is an eBook advertised on the page …

See the Red "button" with the large price tag.

MichaelG.

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Edit: Sorry, just realised that Neil already told you the price.

Edited By Michael Gilligan on 03/02/2015 22:56:21

[andrew winksParticipant @andrewwinks64215]

Hi Phil

Hope I have some useful info. It appears there is no gap between the back of the saddle and vertical face of the rear shear. The front of the saddle has a tapered gib, adjusted to get the saddle/bed clearance correct. is this of use?

Also I note the grease nipples on the saddle, presumably to lubricate the slide, but surely not with grease? Hydraulic or power steering oil, not engine oil with its detergent additives, is the best for sliding surfaces I recall reading though I've always used a 30W oil for the Taiwan machine.

[CotswoldsPhilParticipant @cotswoldsphil]

Hi Andrew,

It should be ISO 68 for the ways and ISO 32 for everywhere else – no grease. My machine had Molyslip pumped into the headstock bearings – since replaced, see my album. The gib-strip is not tapered, just flat and adjusted with the grub screws on the front of the saddle.

Now then, it looks like a narrow guide machine, your first photo of the front shear and serial number confirms this, as well as the rifle shaped felt wiper.

The gap could be quite small if there is some wear on the guide at the back of the front shear. An ML7 I had, had gaps of 0.014 thou. and the Super 7 is 0.019 thou once adjusted. This is why I'm trying to establish what the gap might have been when the machines left the factory.

It is also possible that the narrow guide has been machined away and the rear shear brought into use without any visible adjustment packing. This would mean that the saddle has been brought forward which might cause misalignment of the lead-screw and half nuts.

So, can you twist the saddle? can you get a small (3 thou as a starting point) feeler in any of the gaps (front and rear shear) . For sure, the saddle should not be bearing on both front and rear shears.

See also this thread **LINK**

There is also another thread dealing with this which fro the moment I can't find

Regards

Phil H

[CotswoldsPhilParticipant @cotswoldsphil]

Hi Andrew and others if watching

Found the other related link

**LINK**

Regards

Phil H

[andrew winksParticipant @andrewwinks64215]

Thanks Phil, I will have a close look, Need to get a new set of feeler gauges, grandson tried to check the corrosive resistance properties by submersion in the fish tank…recently discovered. Workshop now has fingerprint recognition access only!

Something that is bothering me is the obviously after-factory brass skim visible at the right rear of the saddle. So, a wipe down and good lookin-at is required.

Great info in the links. Cheers

Andrew

[ANDY CAWLEYParticipant @andycawley24921]

Posted by Neil Wyatt on 03/02/2015 21:20:58:

V-beds count as narrow guides. They have the advantage of providing positive location (under normal cutting forces) on their own.

You can buy the ebook – for £70!

Neil

Edited By Neil Wyatt on 03/02/2015 21:21:53

You can buy, via Abebooks, the paper back version for £2.95, from India plus £4.00 postage.

Not bad eh?

I've just ordered one😀

[CotswoldsPhilParticipant @cotswoldsphil]

Hi Andrew,

What I can see in your photo of the rear of the saddle is one of the (3) laminated adjustment shims ( Pt No. 75/1304) used to set the working clearance of the Saddle Strip Rear – Pt No A2122. Same for the Saddle Front Strip but only 2 shims. These strips stop the saddle lifting.

The shims are asymmetric and stick out if put in the wrong way round, which can be a balancing act (don't ask). So this probably tells you the saddle has been off at some time.

Regards

Phil H

[andrew winksParticipant @andrewwinks64215]

Thank you Phil. We will remove the saddle when the lad returns from his hitch, clean and measure and see if there has been any damage done in the past. This area is a great repository for fine chips or dust from emery paper so its not going to hurt to clean and inspect. Do some basic checks first to check alignment, we will read up well before disassembly.

Cheers, Andrew

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