Rising to a new Level

[hemmjo]

Oh Marv..... that raises a WHOLE NEW conglomeration of issues. Imagine the government using a pan of Mercury as a reference for level. The EPA would have to get involved, there would be men in hazmat suits, with respirators. Yellow tape strung up all over. They would double bag Ralph's cell phone so they can haul it to an EPA approved Hazardous Waste Disposal Site. ......

Seriously though. This was a very enlightening project for me. It is fascinating to have an instrument as sensitive as this one is. After calibrating my new level, I set up my 6 foot, aluminum bean level on my bench. I used shims under each end until it was "level" then placed this new level on top only to have the bubble almost pegged against one side. Thinking that surely I must have messed up the calibration of my new level, I turned it 180º and had the same reading. Being about 3 graduations from center, each graduation represents .005 per foot. 3 x .005 = .015, my level is 6 feet, 6 x .015 = .090. Putting .090 shim under the low end brought my new level into the center, and barely moved the bubble on my carpenters level

I was able to tweak a bit of twist from my lathe bed already. I have to wait a few days to see how things settle since I made those adjustments.

John

[Toolmaker51]

Seems few of the places I've worked had "real" levels. I regarded my investment as a useful treasure. One feature; the best evidence possible when a discussion heats up about why certain lathes run well or not.

Often like this. "What ARE you doing?"
This lathe isn't turning straight.

(Now, one of two things happen. #1 is "Wow, can you fix it?")

Or

"Don't waste time dammit, set the tailstock"
I tried that, thinking your shop was set-up correctly. It's not.
"No one else says that!"
Any of them still work here?

[Ralphxyz]

and where would I get a pan of mercury?

I used to love playing with it in my hands when I was a kid, we got it from broken thermostats, which luckily my Dad had
a Plumbing and Heating business so we always had lots of old thermostats.

Later on found out that wasn't such a good thing to play with, of course I was always the one tending the lead pot so maybe the
layer of lead on my hands protected me from the mercury.

Ralph

[Frank S]

When we were kids we could walk into most any country rx/all drug store and buy just about every chemical known to man and powdered raw elements or even a small bottle of mercury. we could also buy beakers of varying shapes or sizes glass tubing Bunsen burners petri dishes you name it if it had to do with chemistry it was available. The town nearest to where I lived was about 10 miles from our house, it was a small town population of maybe 500 but it had a 2 story drug store 1 wall had shelves from floor to ceiling with small bottles of most everything. Some of the stuff required an adult to present for us to be able to buy it if the drugest didn't know us kids very well. OH yeah there was also a soda fountain on the other side. A very popular hangout as well.
It was probably guys like me always blowing up our home experiments that caused those to disappear.

[mklotz]

Probably anyone over the age of fifty played with mercury as a kid, yet you seldom hear of any of them dying of mercury poisoning. The reason is that they were playing with elemental mercury, the liquid, silvery metal form, which isn't particularly dangerous. It's the mercurial salts that are dangerous to humans. Unfortunately, the combination of an uninformed press and health nazis plus a paranoid population has turned mercury, and lead too, into their most recent bugbears. Wait until they learn that ordinary table salt is composed of sodium, which catches fire in contact with water, and chlorine, a poisonous gas used by the Germans in WWI.

Mercury has long been used to float scientific equipment. One example is the floating collimator...

https://en.wikipedia.org/wiki/Floating_collimator

[Toolmaker51]

I admire Marv Klotz's ability to clarify topics. Some responses might be intense, and certainly out of range for me, but his effect on the forums is undeniable.
Not to say other contributors are lessened in my eye, there are many.
This particular morning, re-read several; and finally sunk in.

[gatz]

I've used Plaster of Paris for mounting a vial in an antique level, which had no adjustment.
I set it up on the mill table (already level with a precision level), and carefully shimmed with whatever was handy.
Poured the pasty mix in, then did the 180º check before allowing it to set up.
Worked good and the Plaster of Paris is cheap at the local hobby store.

[wizard69]

I guess that depends upon how you define “need”. Having the main ways level, on any machine tool, is an advantage for many setup challenges. As for lathes in general, yes removing twist is a major justification for leveling.

Another thing to remember, Ralph...

The lathe does not need to be level*. What is needed is to remove any twist from the bed. A level is just a convenient tool with which to measure twist.

--
* Lathes are regularly mounted in ship machine shops where level is something that only happens when docked.

This is true. The point I’m trying to make is that a level machine tool aids in setup work. While it might upset a traditional machinist, I’ve used an electronic protractor on many occasions to get a “good enough” setup. That does require a level table to begin with.

I might be a bit obsessive here as I even leveled the little bench my grinders are on.

[mklotz]

While it might upset a traditional machinist, I’ve used an electronic protractor on many occasions to get a “good enough” setup. That does require a level table to begin with.

Set the level on the (unlevel) table and press the "zero" button. From then on all angles will be relative to the table and not to the local gravity vector. It's one of the nice features of an electronic level, as opposed to a fluid bubble type.

Yes, it's certainly good to have a work surface relatively level to prevent stuff rolling off, etc. but one doesn't need a precision level, the type used to untwist lathe beds, for that degree of "leveling".

[Toolmaker51]

I [whilst patting oneself on the back] am fairly traditional, until point new things offer solutions unavailable before. I like digital levels, like setting angles on my new brake, which has no calibration at all, just stops.