Levelling Myford Super 7

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Levelling Myford Super 7

This topic has 13 replies, 9 voices, and was last updated 8 May 2021 at 14:16 by old mart.

Viewing 14 posts - 1 through 14 (of 14 total)

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7 May 2021 at 16:45 #28149
Terry Holden
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@terryholden56477
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7 May 2021 at 16:45 #543729
Terry Holden
Participant
@terryholden56477
I have borrowed an engineers high accuracy spirit level to level my newly installed Super 7.

It is a fiddle but I have managed to get both beds in synch but they are an equal amount out of level back to front i.e. looking from the end. In other words with the level across both beds it reads exactly the same at both ends of the beds and the bubble is the same amount off centre at both ends. Does this matter I suspect not.

Also the lathe is also very slightly out of level side to side as looking from the front but again I suspect that is not important. Am I correct ?

Thanks

Terry
7 May 2021 at 16:56 #543732
Buffer
Participant
@buffer
I guess it's not important for some work but I think most people who try to level a bed actually level the bed not just level the error. I would properly level it then do the turning test on about a 4 od 5 in h long bar to take out any taper.

Choice is yours really, does it matter if your parts are tapered?
7 May 2021 at 16:59 #543733
blowlamp
Participant
@blowlamp
It sounds good to go to me.

Martin.
7 May 2021 at 17:23 #543737
Rod Renshaw
Participant
@rodrenshaw28584
There is no actual essential need or virtue in having the lathe level except that it makes it easier to fit and align accesories etc. They use lathes on ships after all. The need is to get any twist out of the bed, which you seem to have done. Acid test is does the lathe turn parallel? You can do intial tests with a test bar which fits in the headstock mandrel and final teats turning 2 bobbins on a piece of steel held in the chuck, and check they are the same diameter.

Rod
7 May 2021 at 18:56 #543748
old mart
Participant
@oldmart
We are refurbishing an Atlas 12 x 24 which has a bed like a Myford, and we raised it up with a large 40mm aluminium block at the headstock end to give clearance for screw adjustment at the tailstock end. I have a Moore & Wright spirit level, but it may not be sensitive enough. The actual leveling will probably be done by turning test pieces when the lathe is up and running. One of my test bars is about 13" long, which may help. I was thinking of a 20" long bar for the turning tests

Edited By old mart on 07/05/2021 18:58:12

Edited By old mart on 07/05/2021 18:59:49
7 May 2021 at 19:31 #543753
Dave Halford
Participant
@davehalford22513
Posted by Terry Holden on 07/05/2021 16:45:56:

I have borrowed an engineers high accuracy spirit level to level my newly installed Super 7.

It is a fiddle but I have managed to get both beds in synch but they are an equal amount out of level back to front i.e. looking from the end. In other words with the level across both beds it reads exactly the same at both ends of the beds and the bubble is the same amount off centre at both ends. Does this matter I suspect not.

Also the lathe is also very slightly out of level side to side as looking from the front but again I suspect that is not important. Am I correct ?

Thanks

Terry

Lathes are used in ships when under way, just make sure the bed isn't twisted, which you have.

Job already done.
7 May 2021 at 20:11 #543759
Michael Gilligan
Participant
@michaelgilligan61133
Terry,

Have a look at my second post on this page from 2015: **LINK**

https://www.model-engineer.co.uk/forums/postings.asp?th=102987&p=2

MichaelG.
7 May 2021 at 20:13 #543760
Michael Gilligan
Participant
@michaelgilligan61133
< double post, deleted >

Edited By Michael Gilligan on 07/05/2021 20:14:03
8 May 2021 at 00:09 #543791
Hopper
Participant
@hopper
Precision levelling of the bed can be a bit of a waste of time on old worn lathes. A few thou of wear in different spots on the ways can a) Throw out the reading of the precision level and b) Throw out the movement of the carriage causing the lathe to turn out of parallel even with a perfectly levelled bed.

A turning test of a piece of 1" diameter steel about 4 to 6 inches long with no tailstock in place is a better way to go in the real world.

Other than that, the lathe can be set at any old angle. I set my lathe bench up so the drip tray funnels all the oil to the back corner where I can scoop it out from one place. Then set the lathe flat on the bench on its riser blocks and set it up the last few thou using the above turning test. It turns parallel within a few tenths of a thou over 6".

Edited By Hopper on 08/05/2021 00:18:10
8 May 2021 at 00:16 #543792
Hopper
Participant
@hopper
Posted by old mart on 07/05/2021 18:56:32:

We are refurbishing an Atlas 12 x 24 which has a bed like a Myford, and we raised it up with a large 40mm aluminium block at the headstock end to give clearance for screw adjustment at the tailstock end. I have a Moore & Wright spirit level, but it may not be sensitive enough. The actual leveling will probably be done by turning test pieces when the lathe is up and running. One of my test bars is about 13" long, which may help. I was thinking of a 20" long bar for the turning tests

Too long. To test the bed alignment you need to not use the tailstock centre. So a piece of 1" bar about 4 to 6 inches long with no tailstock centre is the usual turning test piece.

After that is set, you can then use a longer piece with a tailstock centre in place to set the offset adjustment of the tailstock so the machine turns parallel between centres.

The Myford ML7 Owners Manual has a very good description of both leveling and and test piece turning procedures to set up a new lathe. It recommends the turning test alone as being suitable if no precision level is available. PDF copies freely available on the net if you google it.
8 May 2021 at 08:43 #543815
Howard Lewis
Participant
@howardlewis46836
From what is posted, the lathe bed is free of twist, but the whole thing is tilted either towards or away from the operator.

Unless flood coolant is used, with the need to send coolant towards the drain back to tank, a slight inclination in either plane will will be of no consequence.

My preferred method of levelling a lathe to ensure that the bed is twist free, is the same as Old Mart's. .

1/2 UNF being 20 tpi means that rotating a nut by one flat changes the height by 0.00833", giving a fairly precise means of adjustment.

Additionally, the arrangement acts as a riser block for the machine.

My 300Kg lathe sits on 1/2 UNF setscrews in just that way.

Howard
8 May 2021 at 14:12 #543886
Terry Holden
Participant
@terryholden56477
Many thanks to everyone who replied – much appreciated.

Double checked it this morning and the level is spot on down the full length of the beds so it should machine accurately. As confirmed above I dont think the very slight "tilt" backwards/forwards and side to side will affect its accuracy.

I will however get some suitable material and turn a test piece to check.

Thanks again.

Terry
8 May 2021 at 14:16 #543890
old mart
Participant
@oldmart
Some lathes are deliberately tilted one way or the other to aid the drainage of coolant.
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