Levelling a lathe?

[Mark CParticipant @markc]

Its also going to be heavy (if filled with ethanol) at roughly 3.8 tonnes without the vial glass or housing…..

(4.8 m3 internal volume for anyone wanting to know how I worked that out)

Edited By Mark C on 28/08/2016 12:02:09

[HopperParticipant @hopper]

Posted by Mark C on 28/08/2016 12:00:31:

Its also going to be heavy (if filled with ethanol) at roughly 3.8 tonnes without the vial glass or housing…..

(4.8 m3 internal volume for anyone wanting to know how I worked that out)

Edited By Mark C on 28/08/2016 12:02:09

What temperature would that be at?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Mark C on 28/08/2016 12:00:31:

Its also going to be heavy (if filled with ethanol) at roughly 3.8 tonnes without the vial glass or housing…..

(4.8 m3 internal volume for anyone wanting to know how I worked that out)

.

Apologies for for my temporary absence, Mark

[pies and mushrooms had to be procured from the market]

At that weight, the natural 'sag' would be phenomenal

… a very well-designed supporting structure is required

… does anyone here have decent Finite Element Ananalysis tools and/or plans for the Forth Bridge ?

MichaelG.

[Mark CParticipant @markc]

Yes Michael, I do have a pro FEA package but I have no intentions of trying to set it up for that let alone wait around for the results! Sag might start to be dealt with by perching the thing on it's Airy points for longitudinal deflection but hoop stress etc might be more of a problem especially if the vial is constant section? This could be an interesting problem for an engineering course (perhaps not beginner level)

Hopper, 20 Celsius? or perhaps it might be different on whatever planet we are working on – this is clearly not of this planet….

Mark

PS. Hope the pies and mushrooms are nice or are they a reference to the way this conversation is going?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Mark C on 28/08/2016 15:17:38:

PS. Hope the pies and mushrooms are nice or are they a reference to the way this conversation is going?

.

The pies are real, Mark

… But unfortunately the seller doesn't do Desperate Dan's favourite.

**LINK** https://goo.gl/images/0w5X8S

MichaelG.

[AjohnwParticipant @ajohnw51620]

Posted by Michael Gilligan on 28/08/2016 10:36:11:

I'm still trying to visualise a 'Sensitive Level' that can also accomodate a 10° angle.

… obviously some clinometers and box-levels can do it, but that's cheating.

.

Just for fun … Here is a graphic illustration of what a 30° slope looks like

[I assume that most of us could mentally trisect that angle]

MichaelG.

You adjust it for 10 degrees in one direction and if the vial is large enough it wont matter if it's tilted 10 degrees in the other direction.

I would have thought that was pretty obvious and did mention adjustment. It really would need adjusting if there was a 10 degree slope across the bed and probably wouldn't go that far.

John

–

[Michael GilliganParticipant @michaelgilligan61133]

John,

I think you are missing the point.

… Let's just call it a day.

MichaelG.

[capnahabParticipant @capnahab]

A common misconception is that lathes need to be level – they don't (some are designed with angled beds). They do benefit from being fixed down without any twist in the bed and the engineer's level helps with this (it doesn't matter is both ends are angled at 0.5 degrees, for example, as long as its in the same direction), but the acid test is actually turning something or checking with a test bar.

Neil

Not according to DSG, they do like it level and you only have to fix it if you are a purist/ heavy duty man and then it requires 6 holes in the garage floor 12 inches deep by 4 inches square.

I have spent sometime with a too short 22mm spanner levelling a lot of lathe and indeed its now test bar time. Not sure if the image below will be the right way round – usual problem.

[HopperParticipant @hopper]

How do you level the bed of a well used 30-year-old lathe that inevitably has a few thou of wear more on one shear than the other at the headstock end where the saddle is mostly used? It's not uncommon for  the front shear to be worn down by five thou in this area, enough to send a sensitive level absolutely loopy.

Edited By Hopper on 31/01/2017 23:31:24

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