Engineers level

[Clive HartlandParticipant @clivehartland94829]

Without doubt the end caps of the tubular level will be fixed with threads and maybe a grubscrew to lock it in place. The bubble itself will as Michael says will be set in plaster of Paris. Under the bubble you will find a folded paper like a concertina. This presses the bubble gently to the aperture where you view it. The replacement bubble will have a dimple on one end and when you set it in the tube the dimple must be clear of the plaster of Paris so no lateral pressure can snap it off. Allow plenty of time for the Plaster of Paris to set hard, maybe a week or so as it will move the bubble as it dries. Clean any threads carefully and put the lightest smear of grease on them. To set up the bubble you will need an adjustable table to end for end the level as you adjust the bubble to stay in the middle when you end for end the level.Allow plenty of time for the bubble to settle as you adjust and do not touch the bubble ( Thermal shift)

Clive

[Swarf, Mostly!Participant @swarfmostly]

Gentlemen,

Thank you for your inputs. I'll have another go and report back.

As to grub screws, the outer cover tube extends right to the flanges on the end caps – I didn't see any signs of grub screws.

Thanks again and best regards,

Swarf, Mostly!

[John Stevenson 1Participant @johnstevenson1]

If you are going to be so pedantic as regards getting your lathe bed level [ why I don't know, industry used the time honoured formula of a straight line drawn between two chip shops ] then just float it on a bed of mercury.

 

But this then raises the question if you get 4 points on the bed to within a eyelash of a gnats left bollock, who's to say the bed is actually level after 40 years being moved from A to B and then Milton Keynes.

 

The real reason is that it's actually more informative to talk about it than go out into a cold workshop and actually use the machines.

Edited By John Stevenson on 09/02/2015 00:08:06

[Paul LousickParticipant @paullousick59116]

A simple and cheap method to level a lathe with a plumb bob

[John OlsenParticipant @johnolsen79199]

I always understood the point of the exercise was to get the lathe to turn parallel rather than being worried about its relationship with the local gravitational field. So I would expect to see it done with a test cylinder and dial gauge rather than a precision level. I would comment that one of the comics has described how to make your own precision level, I think it was ME but can't recall. I think also it was using the technique where a straight tube is bent slightly by applying pressure. Cheap glass tube may of course already be somewhat less than straight anyway.

There was also something written many years back in ME about the virtues of actually leveling machines, I think possibly by Tubal Cain. (Tom Walshaw) The advantage was more in the context of milling machines and shapers, where a workpiece can then be set up with the level. The level may not be on the face to be machined, it may be on some other face, perhaps even vertical. Or with a suitable sine bar arrangement, at some other angle. While I can see that this would be a workable method, I've never attempted to apply it.

John

[Swarf, Mostly!Participant @swarfmostly]

Good morning,

A progress report concerning my Rabone Chesterman engineer's level:

I have now removed both the end caps (or plugs), the outer tube, the two end caps (or plugs), two small not-quite-flat leaf springs, sundry glass fragments, a folded strip of paper and several teaspoons full of powdered plaster of Paris from the inner tube.

The end caps (or plugs) were a tight press fit in the inner tube – no threads, no grub screws. Their flanges retained the rotatable outer tube with the two leaf springs providing friction to the outer tube. The springs seat in shallow slots milled in the back of the inner tube, one near each end.

I found no trace of a 'pip' on the wreckage of the vial – if there was one the p-of-P wasn't clear of it! Maybe the vial I've just removed was, itself, a replacement, fitted by an un-tutored repairer?!?!

Plaster of Paris seems to be readily available – I've sought a quote for a replacement vial. (The smelling salts are to hand!)

Pressing in the end caps (or plugs) when the repair is complete promises to be fun – the flanges need to be accurately in line with each other and when I wrote 'tight press fit' I meant it; the metal (chrome-plated brass?) inner tube was flexing!! I hope the mice haven't eaten my tallow ……

I've included the maker's name – other manufacturers' levels will be different.

Best regards,

Swarf, Mostly!

[Speedy Builder5Participant @speedybuilder5]

Question, how do lathes work on a boat?? Levels – do we really need them. If you do use them I suppose the suds drain better.

[Nick_GParticipant @nick_g]

Posted by Speedy Builder5 on 09/02/2015 11:59:17:

Question, how do lathes work on a boat?? Levels – do we really need them. If you do use them I suppose the suds drain better.

Because the lathe does not have to actually be level. Just true and square to it's self.

When setting up a lathe on 'dry land' it's easier to deal with a known quantity so to start off level assists the setting up in achieving this.

Nick

[Bob Brown 1Participant @bobbrown1]

It has all to do with twist in the bed, it can be at an angle as long as there is no twist in the bed, if there is a twist in the bed it will machine a taper simples.

[Ian S CParticipant @iansc]

The important thing is that the bed is parallel to the spindle, and across the bed is the same angle at the tail stock end as it is at the head stock, it can be useful at times to be level, but not essential, some lathes are sloped quite steeply to the tail stock end to clear swarf and cutting fluid. Wonder if anyone has tried a lathe on the Space Station?

Ian S C

[mark costello 1Participant @markcostello1]

Worked with a chap that was a mmachinist in the U S of A Navy. The lathe He ran was 90' in length. During rough seas He was not allowed to use it as You could watch it flexing during the wave motion.

FIL used to watch W+S #2's being unloaded in the winter by attaching them too electric poles and driving off with the trailer, letting them fall on frozen ground, with no apparent difficulities later.

A w+S #2 He personally ran for years was involved in Anchor Hocking plant fire. The floor burned through and the lathe fell into the basement. After the fire was put out the lathe was pulled out and sent out and rebuilt used many years after that.

[Swarf, Mostly!Participant @swarfmostly]

Good morning,

I guess this post is really (but not exclusively) addressed to Clive:

Following my post dated 9th February, I've bought a replacement vial for the Rabone level, together with 750 gms of plaster of Paris.

Having disposed of some other tasks, I'm ready to fit the vial to the inner metal tube. I have two questions:

The vial I have bought has a pip at one end and you (Clive) advised keeping the plaster of Paris clear of the pip – space is kind of short in there and visibility is restricted, please can you offer any tips regarding this aspect of the job? (I did toy with the idea of putting a bit of bicycle valve rubber over the pip but the pip isn't big enough for that.)

I anticipate needing about a teaspoonful of plaster for each end of the vial and would like to minimise waste. Mixing a small quantity seems more tricky than mixing a large amount, do you have any tips for this?

I understand that I need to thoroughly clean the inside of the metal tube as any traces of old plaster will accelerate the setting of the new.

I'll take some photos when I actually start the job.

Thanks and best regards,

Swarf, Mostly!

 

Edited By Swarf, Mostly! on 21/03/2015 11:15:55

[Neil WyattModerator @neilwyatt]

Inspired by this thread, I've blagged a precision level from Ar54c Euro Trade as the top prize in a little photo competition.

Take a look in the latest MEW – digital out today, paper one should arrive with subscribers in the next few days.

Neil

> I anticipate needing about a teaspoonful of plaster for each end of the vial and would like to minimise waste. Mixing a small quantity seems more tricky than mixing a large amount, do you have any tips for this?

Now that's what I call economising! Get a tube of Dial flexible filler from B&Q. Although it's flexible it will be plenty firm enough, and you can use as little as you like.

[Clive HartlandParticipant @clivehartland94829]

In answer, OK, the amount of plaster you make up is immaterial as you need a small qty. to use as a sample to see how long it takes to set.

Firstly make up your little piece of foolscap paper like a little concertina which will sit under the bubble and lift it up. This may take a bit of fiddling as it must not be tight fit, just enough to slide the bubble into the tube.

Regards the pip, it is a weak point and if plaster is set around it it can snap off. Basically just clear the plaster from around the pip with about a half mm clear. Use a match stick or similar to place the plaster in place and if you have clearance problems with the pip then perhaps make a space in the end cap. No part of the tube should touch the bubble except where it rests up against the aperture.

Allow time to set and add another 24 hours. Your sample will tell when it is completely set. As to the flexible filler that is a no no as it takes too long to dry and also contracts somewhat.

Clive

[Swarf, Mostly!Participant @swarfmostly]

It's me again!!

Thank you, Clive, for your advice.

I made a trial mix of the plaster of Paris to get a feel for the stuff. I then started the reassembly. Here is a photo of all the parts of the level, including the new vial and the original paper 'pressure pad' :

You can see the two end plugs – not a screw thread or grub-screw in sight!

My first step was to insert the vial and the pressure pad into the inner metal tube and position them as accurately as I could with respect to the window aperture. I then secured the vial temporarily with Sellotape, hoping that it wouldn't pull the coloured filling from the vial graduations when removed later.

Inserting the plaster in the non-pip end was messy but simple. I let that harden for 24 hours. In view of Clive's cautions regarding the pip, I considered and rejected several methods of inserting the plaster in the pip-end. The method I chose was to cut off part of the tip of a disposable plastic pipette (my wife uses them to handle her pond-life microscopy specimens). Here's a photo of a complete pipette and the pruned one I actually used:

I positioned the metal tube and vial, end-up, supported by a quartz halogen desk lamp (it was to hand and saved me the bother of going to the workshop for the retort stand and clamp! ). Then, holding the pipette with its cut end over the vial's pip with one hand and holding the pot of plaster with the other hand, I spooned the plaster into the open end of the metal tube (with the other hand ). I 'broggled' the plaster down into the tube with one of those wooden coffee stirrer sticks. When I thought I'd inserted enough plaster, I applied a couple of lumps of Plasticene to keep the pipette in position until the plaster had set.

The plaster sets in about 20 minutes, I left it for a couple of hours and then fettled the plaster from the rim of the tube end and then removed the pipette. The pipette has raised graduations which the plaster was reluctant to release but perseverance prevailed.

I was eager to see whether I'd adequately protected the pip, here's a photo looking down the open end of the tube, the bright central spot is the pip.

Not the easiest thing to photograph but I think you can see I was fairly successful (except that I've put in too much plaster and it's going to be a b***h to remove the excess) . I have to do that to make room for the end caps.

I'm going to make some sort of a fixture to help press the end caps into the tube with their lugs in line with each other and in correct relation to the window in the tube.

Best regards,

Swarf, Mostly!

 

Edited By Swarf, Mostly! on 26/03/2015 20:01:05

[Clive HartlandParticipant @clivehartland94829]

Nice work on the bubble, wait till you have 10 lined up to do like I had in the Base Workshop. Working the Plaster is a bit of an art really but you have the hang of it now so well done.

Clive

[Swarf, Mostly!Participant @swarfmostly]

Hi there, Clive,

Thank you for your encouragement.

Ten-off, well no, but when I do get this one finished I've got a clinometer like Clive's to do. The vial I bought for that has no pip, it's blunt both ends. However, I haven't dismantled it yet so I don't know yet what provisions there are for setting it to zero!

Thanks again and best regards,

Swarf, Mostly!

[mechman48Participant @mechman48]

'FIL used to watch W+S #2's being unloaded'… W+S #2's ..??… abbreviations & acronyms are fine ..if you know what they are..

George.

[Anonymous]

Posted by mechman48 on 27/03/2015 08:27:28:

'FIL used to watch W+S #2's being unloaded'… W+S #2's ..??… abbreviations & acronyms are fine ..if you know what they are..

W+S #2 = Warner & Swasey #2 capstan lathe – by industrial standards one of the smaller capstans, weight about 3000lbs.

Andrew

[Neil WyattModerator @neilwyatt]

FIL – Father in Law

Neil

[ianjParticipant @ians]

I know this is an old thread but I to have a Rabone level the same as yours Swarf Mostly with a broken vial. Can you

remember where you bought your replacement vial from?

I see "**LINK** have one which may be suitable (5895/101 – Ground vial, 58x12mm, sens 0.05mm/m) But at £40 I'm a bit reluctant to chance it. I was wondering if you found a cheaper source ?

 

Thank You Ian

Edited By ian j on 20/11/2017 11:22:47

Edited By ian j on 20/11/2017 11:23:32

Edited By ian j on 20/11/2017 11:24:43

[pgk pgkParticipant @pgkpgk17461]

Ian, I had a look around the web and found this **LINK**

It may be worth a punt at that sort of price.

pgk

[Gary WoodingParticipant @garywooding25363]

Hmm. I interpret the specs as 2mm in 90", or approx. 3minutes of arc, or just over .01" per foot.

Is that accurate enough for levelling a lathe?

[Clive HartlandParticipant @clivehartland94829]

For the purpose it is needed for the reading is of no consequence as you are using it as a comparator when end for ending. I have very seldom used a bubble to measure deflection, as most instruments have a scale anyway.

Clive

[Ian PParticipant @ianp]

Posted by Clive Hartland on 20/11/2017 14:03:47:

For the purpose it is needed for the reading is of no consequence as you are using it as a comparator when end for ending. I have very seldom used a bubble to measure deflection, as most instruments have a scale anyway.

Clive

I agree its not the reading or a measurement that matters, but the resolution of the indicator does. If the level can only discriminate to 10 thou in a foot then the bed could be twisted 10 thou but you would not know.

I know I'm simplifying things a bit but as far as I see it the use of a precision level to 'measure' the twist in a lathe bed does not have much purpose. Far better to get the lathe level, (or wherever it needs to be that the coolant runs to the drain hole) then adjust the feet or bolting down facility to make the lathe turn parallel.

Ian P

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