Engineers level

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Bogstandard2 on 02/01/2015 10:17:54:

I would suspect that in the link shown, because no prices for the vials are shown, then they too have extortionate rates of min. order prices. I hate it when these companies come onto the net advertising their wares and don't give prices, a sure fire way of knowing that they are most probably trying to rip you off.

.

John,

Although are no 'list' prices shown for the ground-tube precision vials; the general purpose ones are priced on the website … [example] … and they seem keen to accept enquiries about the others.

MichaelG.

[jason udallParticipant @jasonudall57142]

Re lunar soc.

Well there you go.
And I always thought it was to have light to get home by.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by jason udall on 02/01/2015 11:45:40:
Re lunar soc.

Well there you go.
And I always thought it was to have light to get home by.

.

That's why I posted my comment.

[Neil WyattModerator @neilwyatt]

> And I always thought it was to have light to get home by.

A vicious rumour spread by their London-based rivals.

Neil

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Neil Wyatt on 02/01/2015 10:14:01:

It doesn't matter, the act of measuring will impact on the system, however you do it. Even placing a level on the lathe bed will deflect it…

Careful Neil. We're getting into the realms of quantum physics and heisenberg's Uncertainty Principle!

Russell.

[Gordon WParticipant @gordonw]

I got a lift to the pub today, again. Talking to a mate who was telling the story about when he was a fully trained machine man. Spent about 2 weeks scraping and leveling a big lathe, put slings on to turn it round and do more work. Set down ready for work and of course it was all out again PS this was true even if no one was looking at it.

[Russell EberhardtParticipant @russelleberhardt48058]

Posted by Gordon W on 02/01/2015 16:43:12:

PS this was true even if no one was looking at it.

Ah but how do you know?

Russell.

[Gordon WParticipant @gordonw]

Because he told me so, he is and was stone deaf , would the speed of sound change?

[colin hawesParticipant @colinhawes85982]

It seems to me that, in an amateurs workshop, the only important thing is to make sure the bed isn't twisted when bolted down; the quickest way to detect this is with an accurate spirit level across the bed at each end. However this spirit level is used as a comparator so actual calibration is not important. Many lathes, including mine, have never been checked in this way and still turn accurately. It will come as a surprise to many amateurs that a steel bar 1"x2" and 18" long will measurably sag under its own weight so a bar in the lathe can do the same which would indicate that there is no point in being too concerned with extreme levelling precision. Colin

[Michael GilliganParticipant @michaelgilligan61133]

Posted by colin hawes on 02/01/2015 17:30:47:

It will come as a surprise to many amateurs that a steel bar 1"x2" and 18" long will measurably sag under its own weight so a bar in the lathe can do the same …

.

Colin,

A the risk of starting another civil war, by the mere mention of his name:

It is worth noting that Dr. Georg Schlesinger specifies a Test Mandrel which is hollowed-out, to avoid sag [and was using such mandrels in 1902].

MichaelG.

[Bob Brown 1Participant @bobbrown1]

I intend to use a 2" alloy tube, 6mm wall thickness so sag should be less of a problem, but all in all it will depend on how accurate you can measure, me down to probably less than 0.005mm and if you are using a micrometer depends on how good you are getting repeatability.

Bob

[NJHParticipant @njh]

Good grief Bob!

What are you going to make in your shed – space ships?

Norman

 

 

 

 

Edited By NJH on 03/01/2015 10:18:32

[Ian PParticipant @ianp]

In a dream last night, the simple answer came to solve the lathe levelling problem! It was a technique to eliminate even the sag of a test bar and dramatically reduce any bending effects on the lathe bed due to is weight. I was thinking about Bob's large diameter tubular test bar and realised that if his tube had unequal wall thickness it would sag different amounts depending on its rotational position.

Unfortunately the technique will not work with all makes of lathes (Myford's with the little oil reservoir gadgets on the headstock bearings would be tricky but sealed for life rolling bearings should be OK), Long bed lathes in workshops with limited headroom would be a challenge too, but otherwise all we have to do is change the lathe orientation so that the main spindle rotates in the vertical axis.

Who is going to be the first to try it?

Ian P

[Ian L2Participant @ianl2]

Posted by Ian Phillips on 03/01/2015 21:47:15:

In a dream last night, the simple answer came to solve the lathe levelling problem! It was a technique to eliminate even the sag of a test bar and dramatically reduce any bending effects on the lathe bed due to is weight. I was thinking about Bob's large diameter tubular test bar and realised that if his tube had unequal wall thickness it would sag different amounts depending on its rotational position.

Unfortunately the technique will not work with all makes of lathes (Myford's with the little oil reservoir gadgets on the headstock bearings would be tricky but sealed for life rolling bearings should be OK), Long bed lathes in workshops with limited headroom would be a challenge too, but otherwise all we have to do is change the lathe orientation so that the main spindle rotates in the vertical axis.

Who is going to be the first to try it?

Ian P

Hope I don't start dreaming lathes.

[Robert DoddsParticipant @robertdodds43397]

Ian P,
Were you perhaps dreaming about MEW 224? By some strange coincidence there is just such a vertical lathe on the cover, courtesy of Jock Miller. Unfortunately its the wrong way up as its sited down under in New Zealand.
If you don't get MEW there is a preview description of the lathe on this site's home page.

Bob D

[pgk pgkParticipant @pgkpgk17461]

Posted by Ian Phillips on 03/01/2015 21:47:15:

In a dream last night, the simple answer came to solve the lathe levelling problem! It was a technique to eliminate even the sag of a test bar and dramatically reduce any bending effects on the lathe bed due to is weight. I was thinking about Bob's large diameter tubular test bar and realised that if his tube had unequal wall thickness it would sag different amounts depending on its rotational position.

Unfortunately the technique will not work with all makes of lathes (Myford's with the little oil reservoir gadgets on the headstock bearings would be tricky but sealed for life rolling bearings should be OK), Long bed lathes in workshops with limited headroom would be a challenge too, but otherwise all we have to do is change the lathe orientation so that the main spindle rotates in the vertical axis.

Who is going to be the first to try it?

Ian P

I tried that today but my major issue was how to find a center point for suspending the lathe end. Finally I tried a long bar through the lathe spindle with a monomolecular strand fixed to it's centre (a challenge in itself) but even then the tiniest draught causes the ways to deflect. I'm also waiting on local magnetometer readings in case tere might be some side load effect I need to allow for.

pgk

[jason udallParticipant @jasonudall57142]

Vertical spindle lathes. ..plenty used …big stuff usually. .bells and the like
..

[Paul LousickParticipant @paullousick59116]

I have an early model Southbend lathe and this is the original instruction for mounting it on a bench.

A 3-point mounting system seems like a good idea, unless you can guarantee the accuracy of the lathe set-up. Bolting it down at 4 points will twist the lathe if it not completely level.

Paul.

[Swarf, Mostly!Participant @swarfmostly]

Hi there, all,

I have a Rabone Chesterman engineer's level with a broken vial.

Thanks to this thread, I am now aware of a potential source for a new vial.

However, I can't see how to get the old broken vial out! The inner metal tube (that houses the vial) has end caps (or plugs) with flat extensions that are secured to the cast iron base by a screw one end and a stud and a pair of nuts at the other end.

My first thought was that the end caps (or plugs) are screwed into the metal tube but trying to unscrew them gave only an ominous creaking from the glass vial.

I'd prefer to get the old glass vial out in sufficiently large pieces to enable me to correctly specify the replacement!

If anyone here has trod this path before me, please, please, lighten my darkness?!?!

Just to clarify – I do mean Rabone Chesterman, not the one pictured up-thread one page.

Best regards,

Swarf, Mostly!

 

Edited By Swarf, Mostly! on 07/02/2015 19:41:00

Edited By Swarf, Mostly! on 07/02/2015 19:47:00

[Michael GilliganParticipant @michaelgilligan61133]

Swarf …

Many of the old vials were 'potted' into the protective tube with a mix of Plaster of Paris and [sorry, I can't remember what ]

MichaelG.

[Ian L2Participant @ianl2]

If its only plaster of paris would soaking it water for couple days allow it to come out?

[Swarf, Mostly!Participant @swarfmostly]

Hi there, Michael and Ian,

Thank you for your inputs.

I know about the Plaster of Paris but I haven't reached that yet!

I've got to get one or both of the metal end caps (or plugs) out first!

I need to know how they're attached – threaded, press-fit or what?!?!

Best regards,

Swarf, Mostly!

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Swarf, Mostly! on 07/02/2015 20:59:54:

I've got to get one or both of the metal end caps (or plugs) out first!

I need to know how they're attached – threaded, press-fit or what?!?!

.

On most of the ones I have seen, the caps are threaded … but you might also find some tiny grub screws [three per cap].

MichaelG.

[Neil WyattModerator @neilwyatt]

It looks like Ketan has been monitoring our conversations as I see he's just started stocking 0,02mm/m levels!

**LINK**

Neil

[Michael GilliganParticipant @michaelgilligan61133]

The little 'Frame Level' looks rather nice.

MichaelG.

[Author]

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