How to level BOTH the Myford cabinet and the lathe bed?

[choochoo_balooParticipant @choochoo_baloo]

I'm hoping to move my Myford ML7 on Myford cabinet into its new home soon. Having used a piece of thick carpet whilst 'playing about' in its old home, I want to set in up on anti-vibration feet, https://www.myford.co.uk/acatalog/4-MACHINE-ANTI-VIBRATION-PADS-1768.html

to:

a) make future movement easier to raise offo of floor

b) sit better – high speed is a tad shaky

…but after watching this detailed video on lathe setup:

I don't know why go through the fuss of using an engineers' level on the machined ways to get the cabinet wrt floor level, when I then readjust the bed following the critical 2 dia turning test (for bed twist)?

I understand the importance of the 2 dia turning test. But this would surely nullify using the bed previously to level the cabinet?

Please clarify for a newcomer!

[choochoo_balooParticipant @choochoo_baloo]

[Michael GilliganParticipant @michaelgilligan61133]

Posted by choochoo_baloo on 20/04/2019 01:32:45:

I don't know why go through the fuss of using an engineers' level on the machined ways to get the cabinet wrt floor level, when I then readjust the bed following the critical 2 dia turning test (for bed twist)?

.

You've sussed it

So far as your Myford is concerned, the levelling points on the top of the cabinet represent its 'floor'

MichaelG.

.

P.S. … Do be sure to watch Part 2

[Roderick JenkinsParticipant @roderickjenkins93242]

There is an argument that the STAND should be set up so that the headstock end, where the drain hole is located, should be slightly lower than the tailstock end if you use coolant.

Rod

Edited By Roderick Jenkins on 20/04/2019 10:05:59

[Howard LewisParticipant @howardlewis46836]

The Myford cabinet is so deep as to be pretty much completely rigid. So that once you have got that to the level that you want, you put the lathe on it and then proceed to take out any twist in the bed.

My experience was that the lathe is sensitive to the torque applied to the holding down nuts. So that once the bed is twist free with a reasonable torque on each nut, resist the temptation to "Give it an extra half flat, just to be sure" .

HTH

Howard

[V8EngParticipant @v8eng]

Many years ago I fitted a set of anti vibration feet to my ML7 cabinet and it’s one of the best things I have done, afterwards the machine felt smoother and quieter in use.

As per Roderick’s post: I too had to set the headstock end of the cabinet slightly lower to get the drain at the lowest point, the lathe was then levelled correctly on it using the adjusting bolts. Now I am dismantling and re-homing it again we may be back at square one on that score.

Edited By V8Eng on 20/04/2019 21:09:21

[Ian HewsonParticipant @ianhewson99641]

Ditto for the feet on my 254s, good fitment, reccomend.

[choochoo_balooParticipant @choochoo_baloo]

That's all helpful chaps as usual.

So to confirm:

I should set up the cabinet (with the 4 anti vibration feet) roughly level – a slight headstock incline should I wish – but ensure load is spread across all 4 feet.

Do the 2 dia turning test as normal, with no reference to the *cabinet*. Therfore I don't need an engineers' level at any stage?

[Ian HewsonParticipant @ianhewson99641]

That has worked for me for many years👍

[Mick HenshallParticipant @mickhenshall99321]

Excuse my ignorance gents but what is the 2" turning test?

Mick 🇬🇧

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Mick Henshall on 21/04/2019 09:35:08:

Excuse my ignorance gents but what is the 2" turning test?

Mick 🇬🇧

.

Mick,

Watch the two videos that started this discussion and all should become clear.

MichaelG.

[SillyOldDufferModerator @sillyoldduffer]

The main reason for levelling is to provide a known reference against which structures can be designed to transfer forces to ground without twisting, toppling, or otherwise stressing the construction.

For example, a brick tower is most stable when erected so that most of the forces (mainly weight) are kept vertical and transferred directly to ground. The easiest way to do this is to level the foundations and carefully align the walls as they go up with a plumb-bob. An arch-bridge is a different proposition because the forces have to travel safely sideways before they can go to ground at an angle making it harder to design a brick-arch than a tower. However, assuming a level is still the easiest way to calculate the forces involved and then to manage construction of the arch. Although it's possible to design and build at angles off vertical, it's simpler to do everything relative to a well-established real-world plane.

A secondary reason for levelling is to provide a reference against which adjustments are made.

As a Myford Lathe on a stand is both a structure and a precision instrument, levelling is done for both structural and adjustment reasons:

1. Most workshop floors will have been levelled somewhat crudely by an ordinary builder. Some floors have a deliberate slight slope added for drainage. Quite likely the floor will be level on average but far from flat. Might be so off as to require attention because the flatter and more level the floor, the less trouble there will be with vibration and erecting the stand. It may be useful to flatten the floor under a machine tool with a proprietary mix that settles level within a temporary frame.
2. When the stand is installed it's useful to level its top to a higher standard than the floor, partly because it will take the weight of the machine better, but also because it makes adjusting the lathe more straightforward in the next stage, if necessary. An ordinary level is 'good enough'. Stage 1 and 2 levelling can be done together with adjustable feet or other methods, but generally the more upright and rigid the engineering before the lathe is installed the better.
3. Many lathes benefit from levelling of the ways. Although it helps remove unwanted stress from the lathe's structure, it also makes it possible to achieve higher accuracy by deliberately twisting the bed to tune out errors. There is a limited range over which this can be done, and it's best not to start with a lathe already badly twisted due to a bent stand on a poor floor. The downside of machines featuring this method of adjustment is they have bendy beds and are more likely to be out of true due to a poor floor or inadequate stand.

Levelling may not matter much – you might have a good floor and a decent stand from the get go, whilst Chinese lathes tend to have stiffer beds, and many industrial machines are massively rigid. Other lathes are more sensitive and I think this is why Myford owners worry more about levelling than others.

It's for tuning out errors that an engineering level is most useful, but as they only register on a surface that's already nearly level, using one might force the full 3-stage levelling treatment.

Once a machine has been set-up rigidly it's not necessary that it be level in operation. Plenty of lathes used on ships at sea…

Dave

[Howard LewisParticipant @howardlewis46836]

"The Amateur's Workshop" pages 27 and 28, and the "Myford Series 7 Manual" pages 42 and 43 describe the turning test method of levelling a lathe, to remove any twist from the bed.

L H Sparey in "The Amateur's Lathe", advocates the use of a D T I, pages 35 and 36.

In all cases, the objective is to ensure that the lathe bed is not twisted, so that it turns parallel, rather than a taper.

As long as the bed is not twisted, the lathe can slope from Headstock to Tailstock, or even front to back, if this will aid drainage of any coolant used.

Howard.

[Mick HenshallParticipant @mickhenshall99321]

I would MichaelG but having tried to type the link details in around half a dozen times with no result I have given up,

I cannot work out whether I is I or 1, I tried searching but no luck will try a google search, the search goes on 🤔

Mick 🇬🇧

[Michael GilliganParticipant @michaelgilligan61133]

Sorry to have inconvenienced you, Mick

… all I did was copy & paste this from the opening post into a new tab:

… but here's a **LINK**

Part 2 should follow automatically.

MichaelG.

[Mick HenshallParticipant @mickhenshall99321]

You haven't inconvenienced me, I am not computer savvy thanks for the link I appreciate it

Mick 🇬🇧

[Michael GilliganParticipant @michaelgilligan61133]

You're welcome, Mick

[Author]

Posts