Chinese Levels

[ieezitin]

I have a Rabone machinist level which I fooled with on the leveling jack and inadvertently threw it out of spec ,it was made in 1945, great tool just don’t have something to re-calibrate it with.

Now I installed a new lathe in my shop this weekend and want to take the twist out of it and level it, I own one of these incredible place anywhere accurate to ½ a degree doo-dads and it reads zero one direction and minus 2Deg the other.

I have the right tool that was made with pride in front of me and I have a tool that lies to me.   God daam im pissed off.

Sorry for the rant.

Anthony.

[Jonny]

Got one some where boxed with test cert labels over the decades, shame i aint seen it for 15 years though.

Lathes 1 degree out then.
Cant beat the old bubble levels, cant get to grips with a £60 USB digi level i imported two years ago, better off doing a visual.

[velocette]

I have a Rabone machinist level which I fooled with on the leveling jack and inadvertently threw it out of spec ,it was made in 1945, great tool just don’t have something to re-calibrate it with.

Yes you can recalibrate your level it just takes a little patience.

Stick it on your lathe bed and read it (How many divisions out from center) Reverse it Put in the EXACT!!!!! same place and read it.

Get the drift of this REVERSING  the level will read as DOUBLE THE ERROR.

Grab the appropriate tools and adjust it in situ until you have the bubble move just under HALF of the Error.

Repeat again re adjust this will be a very small adjustment.

OR to get a true and level surface to calibrate it on.

As with any leveling The trick is to  reverse the level to check for errors.

Even when out of adjustment reversing equals DOUBLE THE ERROR therefore you raise the low reading on the machine to be to be leveled.

And check it with level and then reverse it and check again
 
When both readings are the same from centre of the scale then the machine is level 


Eric

[pete3000]

Unless I am missing something the chinese dodad is working. It has been switched on/zeroed on non level i.e -1 degree, then when turned round it reads double the error i.e 2 degrees?

You could check it against the method above with the spirit level, i.e reversing it on a known level.

Pete

[trevoratxtal]

My Grandfather being a Carpenter/Builder/Engineer showed me how to use a level 'any type' 60 years ago and it still hold true.
It incorporates every thing Velocette reported, but is used every time the level is used.
That is apply the level take a mental note of the reading, Turn the level 180 deg and note the difference,
Half this and this will be the level point.
It was necessary to do this with his 1800s wooden levels as they could alter over night with temperature and humidity so constantly readjusting them was not on.
Try it you will be surprised how accurate it can be.
Early portable levels where straight glass tubes with coloured alcohol, some modern ones have slightly bent tubes with a viscose fluid to slow the wobble.
Having said that the ultimate level is a Triangle of wood as big as possible with a plumb line from the upper point, as used by the Egyptians thousand of years ago. needs reversing the same as above to get the right reading.
My Best Level is an ex Field Gun Setting Level, Brass, about 1 kilo and can be read to less than one second with a vernier scale.
I also use a modern Electronic one.
 The Electronic one is great as it has a magnet and is used to check the Pillar drill Table
Trev

[DavidA]

Eric and Trev seem to be missing the point.

Surely the idea is to get the level correct so it will show any problem with any surface you are checking.

I place a straight bar about a foot long in the vice.  Put the level on it and then tap the high end down until the bubble indicates level. Then I reverse the level on the bar. If the bubble is again in the middle then the level is ok.

If not adjust the level by half the error then repeat the above process. Do this until the level bubble always returns to the middle. You then know that  the bar is level,  and the level is adjusted to this level bar.

You can't adjust a level on a non-level surface.

Dave.

[loply]

You can adjust a level on a non-level surface, the procedure is just the same but you adjust it until it shows the same error irrespective of which way your orient the level.

If this is a high precision level, the surface has to be 'close enough' that the bubble is somewhere near the middle though, if it's all the way to one side this won't work.

[velocette]

Hi to DavidA and Loply

READ MY POST AGAIN  No 3)

1)"OR to get a true and level surface to calibrate it on.

2)  As with any leveling The trick is to  reverse the level to check for errors.

3) Even when out of adjustment reversing equals DOUBLE THE ERROR therefore you raise the low reading on the machine to be to be leveled.

4) And check it with level and then reverse it and check again
 
5) When both readings are the same from centre of the scale then the machine is level 


Eric

[DavidA]

Eric,

I interpreted Anthony's originl problem to be that his level was not reading true as it had been knocked out of adjustment.

i.e  I have a Rabone machinist level which I fooled with on the leveling jack and inadvertently threw it out of spec ..

So the problem appeared to me to be one of getting the thing back to level.

This is why I described the method I use to attain this.

I can't see any point in using a level that isn't reading correctly in the first place.

As for leveling up on none level surfaces,  I use an inclinometer.

Dave.

[velocette]

Hi DavidA

"Many ways to skin a cat" A cat is still a cat

See why you need an inclinometer

Lend it to ieezitin

The object of this Forum is to pass on useful information. Not to prove any superior knowledge

Put the inclinometer to good use to measure the angle of the tangent you have gone off on

Re Read my post again no criticism just advice posted.

PS I do not have an inclinometer

Eric

[ieezitin]

Guys,

Regarding my digital level, i place it across my lathe ways and in one direction it reads -2Deg when i turn it around (180*) it reads zero, unless i am missing something on using a digital read-out level i am believing this is defective.

If this were a spirit level and i did the same thing the bubble should split a line on the vile at the same place in both directions, as should a - /  = digital readout.

I know the technique of reading the bubble then switching direction and shaving off the reading by half, yes i can do this with my machinist level thats out of wack, but in hands on practice this poses a human dilemma trust. with my fading sight coupled without having the minimal required skill of a photographic memory on where the bubble landed the reading before, this can be achieved but if i did it i would always have in the back of my mind is it right and that would just tear me up. In fact i spent about 30 mins doing just what i stated and when i placed what i thought was good for level on the lathe i got poor readings.

My frustration was in the irony of having a Rolls Royce tool specifically designed to do one job and I goofed it up then I resorted to using a tool that totes its the bee-knees and lies to me, if i wanted lies i would phone up my ex-wife she has plenty.

A little more information too, i am really not a perfectionist but in this case i need to be. If anyone is familiar with the 12" x 36" Atlas lathe they all will tell you its probably the most flimsiest built lathe bed on the planet, its capable of giving you more twist than Oliver did when he said " more please" this is my third Atlas thats pased through my shop over the years and i need to iron out the twist and get it Dead Nuts On to get any form of quality results down the line.

Everyone who has posted on this thread has had something positive to contribute. I value that as i am sure all who read this topic will too. I dont know if anyone will catch this but sometimes it pays to read between the lines. Excuse the pun.

Anthony   

Ps, if anyone has a fool-proof way on the correct procedure of leveling a 12" x 36" Atlas please post me full directions and i will buy you and your whole family dinner.

[dsquire]

Guys,

Regarding my digital level, i place it across my lathe ways and in one direction it reads -2Deg when i turn it around (180*) it reads zero, unless i am missing something on using a digital read-out level i am believing this is defective.

Anthony

I believe that your lathe ways are out of level by 1 deg. That is why you get the 2deg and 180deg reading. Try placing some shimstock under one end of the digital level on the ways until you can get it to read level. Now turn the level end for end and let me know what the two readings are.

If this were a spirit level and i did the same thing the bubble should split a line on the vile at the same place in both directions, as should a - /  = digital readout.

This would only happpen if the level were 100% accurate and if the ways were perfectly level.

I know the technique of reading the bubble then switching direction and shaving off the reading by half, yes i can do this with my machinist level thats out of wack, but in hands on practice this poses a human dilemma trust. with my fading sight coupled without having the minimal required skill of a photographic memory on where the bubble landed the reading before, this can be achieved but if i did it i would always have in the back of my mind is it right and that would just tear me up. In fact i spent about 30 mins doing just what i stated and when i placed what i thought was good for level on the lathe i got poor readings.

My frustration was in the irony of having a Rolls Royce tool specifically designed to do one job and I goofed it up then I resorted to using a tool that totes its the bee-knees and lies to me, if i wanted lies i would phone up my ex-wife she has plenty.

A little more information too, i am really not a perfectionist but in this case i need to be. If anyone is familiar with the 12" x 36" Atlas lathe they all will tell you its probably the most flimsiest built lathe bed on the planet, its capable of giving you more twist than Oliver did when he said " more please" this is my third Atlas thats pased through my shop over the years and i need to iron out the twist and get it Dead Nuts On to get any form of quality results down the line.

Everyone who has posted on this thread has had something positive to contribute. I value that as i am sure all who read this topic will too. I dont know if anyone will catch this but sometimes it pays to read between the lines. Excuse the pun.

Anthony   

Ps, if anyone has a fool-proof way on the correct procedure of leveling a 12" x 36" Atlas please post me full directions and i will buy you and your whole family dinner.

I think the reason for the frustration is that the digital and bubble level use a different means of arriving at the same result that causes the problem. If you didn't have the digital level you would have it all level by now and not had a problem because you understand how a bubble level works. It the fact that the digital level works different that is causing all the greif and confusion.

Hang in there Anthony, you will get it figured out. I have confidence in you.

Cheers 

Don

[ieezitin]

Don.

I understand what you have written. Tomorrow night i will venture in the shop and do what you have suggested. i will post results. Thanks

Anthony.

[Fizzog]

I'm an engineering surveyor currently working on the redevelopment of a large airport somewhere west of London, and we regularly make use of those electronic spirit levels. The sensors in them do drift with time (and abuse by the minions) and a self calibration procedure has been built in to every one of them that I've come across in the last twenty years. This is different from just resetting the zero position when you want to work off a sloping datum.
If you run that as per the manufacturers instructions, you should be able to get it to read more or less the same both ways round. I say more or less, as even being fairly rigorous, they always seem to end up with a tenth or so difference between faces.

Been lurking here for ages, and this is the first time I've known enough to make a meaningful contribution (I hope)  

[ieezitin]

Ok!

After reading what has been said i cleared my mind to start from the beginning and educate myself on a digital level,

The digital level works by giving you the sum total of error (mine gives you either % or Degrees) in either direction, or another way to look at it is it just gives you a report its not level by whatever. ok!

It does true. But what I was experiencing was a conflict with a variance in the sum numbers not being equal When I turned the level 180* to double check its readout.

Missing my original instructions that came with it I got to study the LCD display and the menu buttons on it, in my mind this is what I came up with on how this should work. Example if it displayed 0.1* high left, turned around it should read either 0.1* high left OR 0.1* low right (if I am wrong please explain) but I don’t, I got for example o.1* then turned around it reads 0.0, and I could check one area move somewhere else and then come back to the same spot and it would read 0.2 turned around 0.0 and it would flutter.  I said this in my original post

This is my assessment, don’t use a digital level for fine work ever for this one reason, it flutters with its readings and introduces doubt where your trying to concentrate to achieve something (I called it lying), it consumes so much time in trying to fix something that has many causes for its errors, I analogize this to a fly buzzing around your brain stopping abruptly to catch its breath then taking off again. They are not worth your time or money.

I do have a Inclinometer which I dragged out, ten minutes and a pint later I had it tuned in on a non-level lathe, an hour later 4 more pints the machine was level X-Y, accept for six inch stretch in the middle, this is not the levels fault I plainly blame Atlas for that, the bed is too long with not enough meat to support its self, hence the original fly gaining some company.     

Anthony

[trevoratxtal]

Anthony have you considered what  "0.1* high left OR 0.1*" is
one tenth of one deg IE 6 seconds, that is some thing like a fag paper over what 6, 10 feet.
No I did not work it out some one will do it for us, Ha Ha
Truly if that is the error I would not worry about it.
See below Dave sorted me out I got it all wrong so please disregard.

Little know Fact 
for Harrison  lathe owners, the lathe's were set up in the factory on the stands so they would be no twist or sag in the bed , hence the very robust base,  the Base weigh about same as the bed
The reason was they could be used in ships and on army lorry,s without readjustment, just lock/ bolt down where they touch, pad if necessary. do not over tighten.
How do I know, I used them in the RAF in mobile workshops and studied the manual, I vowed to get one when I retired, I did.
That is one of the reason I have one, as I can use it on wheels. works a dream.
Trev

[DMIOM]

Anthony have you considered what  "0.1* high left OR 0.1*" is one tenth of one deg IE 6 seconds, that is some thing like a fag paper over what 6, 10 feet.....

ermmm .... happy to do the sums - but first, what about minutes?   0.1 degree = 6 minutes of arc? - not 6 seconds

tan(0.1 degree) = 0.00175

So over a 6" / 150mm length level that app. 0.25mm or 10 thou just in the length of a level

Over your 6 ft its 1/8"

Dave

[trevoratxtal]

ermmm .... happy to do the sums - but first, what about minutes?   0.1 degree = 6 minutes of arc? - not 6 seconds

tan(0.1 degree) = 0.00175

So over a 6" / 150mm length level that app. 0.25mm or 10 thou just in the length of a level

Over your 6 ft its 1/8"

Dave

Many thanks Dave, 
I knew some kind soul would sort me out, yes indeed minuets not seconds, it puts a different prospective on it. the error is to great.
Now I went and looked at my electronic level / digital clinometer and found it to be 0.01Degree Resolution
Still not good enough for levelling a bendy lathe.
Trev

[ieezitin]

No Problem Trevor.

Here is a little visual on what 1 or 2 deg variance looks like shown in bubble language.


Here you have the shot looking east and showing Zero on the bubble level and zero on the digital level. Notice the .005 shim placed under the digital level.



 




Now here is the shot looking west, the digital level is showing 2deg and I can assure you the inclinometer is still zero. Notice the shim still under the level.







Now you have the shot showing the digital level with the shim 005 shim removed. It shows 0.1, now if you turn it around 180DEG it would read 0.1Deg. Notice the Inclinometer still reading zero







Now here is a shot of the inclinometer reading level on a level surface.







Now here is a shot with the same 005 shim under it, its banging the needle right!! (its hard to see but the shim is on the left)







Pictures speak a thousand words. This Doo Dad is worth as much as an ashtray on a motorbike.

Anthony.

[trevoratxtal]

Anthony them shots are brilliant, it serves the point.
You do have a wonky level, for this kind of work probable Ok for Dry stone walls on the Pennines, but not for  lathes.
I just love this site, learning all the time.
Thank you.
Trev

[Fizzog]

Sorry to butt in again, but are you sure it's not reading 0.2 degrees? Can't be certain, but from the photo it looks like there's a decimal point lit up on the display.

If so, you've only got a 0.1 variation between the two sides, which is about what you can expect from a standard electronic level.
Halve that residual difference, and it's showing your lathe's ways out of level by 0.05 degrees, or 3 minutes of arc. Unfortunately that's about as good as you will be able to determine with that piece of kit. Some manufacturers claim increased accuracy when close to the horizontal and vertical, Stabila for example, but unless it's hiding another decimal place up its sleeve, you'll not get a great deal better just using that.

Like trevoratxtal I've got an old Harrison (a 140 in my case), so not too bothered by this levelling malarkey, just got it roughly right in both directions,  checked there was was a bit of weight on each of the four feet, and so far it's been fine for my novice metal whittling.

For anything accurate, you still can't beat a proper engineers level (or a Wild Leica N3 if we're being really fussy  )

[Pete W.]

Hi there, Anthony,

Please can you tell us a bit about your brass level?

I have one like it except that it has a different base - two sprung gizmos to clamp it on a mortar.  Was yours originally like mine or did it have the brass block base when you acquired it?

Best regards,

Pete W.

[ieezitin]

Fizzog

you are correct there is a decimal point and your math is right.

My point or more sarcastic satire was at the fact that i had to use this tool that is flawed and i have the correct tool that is or was not then calibrated, i have since remedied my problem. And your not butting in your comments and observations are always welcome, i see your a new member thanks for joining and welcome to our little club.

Pete.

here are some close ups of the inclinometer.


















I have owned this from 1985, i was working in Newton Abbot with an engineering company i just started working for designing Flour bagging and stitching machines for Hovis bakeries.

How i acquired it was the old timer i work along side with was just about to retire and we become very friendly, i found out he back in the day  was a chief engineer in the Royal Navy from Plymouth ship yard hence the MOD marking etched in the side of it (the arrow looking down). I just turned out of my apprenticeship and I was at awe of his knowledge, he took me to his own shop where i saw mountains of surplus Navel equipment left over from the war, he was quite the tinkerer.


although he never told me this i do believe this is a gun sight  to hone in within its 20Deg Range, what i have researched is that it sat on a plinth where on the side it read 1 divisions of a degree then to refine to minuets this came into play I maybe wrong, if i am i welcome the facts.



It  has always been in this form i have never tampered with it. all i can tell you is it get used about once every 3 years on average, when like this example its priceless. BTW my Rabone mentioned in the beginning of the thread came from him to, this unit was made in 1944 the Rabone was made in 1945.

one other little thing was he offered me a box of electrical screens and parts, he told me that they were all prototype equipment for radar from the early 1930ies mixed in was Sonar parts too, the official radar did not go on line till 1936, i kick myself now for not taking them considering the importance it played in the Battle Of Britain.

One lives and learns.

Anthony
 

[Pete W.]

Hi there, Anthony,

Thank you for the photos and accompanying explanation.  The CTS logo is of the company Cooke, Troughton & Simms.  They, along with Baker, eventually became the firm of Vickers Instruments.  CTS have a long history in instrument design and manufacture (described in a book whose title I forget - I'll dig it out of the bookcase and post details when I next log on).

I'll also try to find my version of the level and post some photos.

My version might not have been made by CTS - during the 1939-45 war, lots of military items had their design standardised and then were manufactured by several/many firms.  For example, I believe not all Rolls Royce Merlin engines were actually made by Rolls Royce.

Thanks again and best regards,

Pete W.

[DavidA]

Hey Anthony,  That thing was produced the same year I was.  And it looks in better condition.

Dave.