Leveling a lathe?

[whatsit]

How close is close enough with a 12" .0005/10" machinist level? Grizzly model H2683.
Here is where I am. Lathe on new bench. Bench top level and flat. Lathe bolted to table
with .022 shim under front feet. This gets it to the following.
Across the ways the level reads 2 divisions off of level from headstock to end of bed.
Lengthwise on the ways it is 3 divisions off of level all the way down the ways.
So in essence it appears to be evenly out of level both directions on the ways.
So is this going to be satisfactory for accurate turning? Or am I being a bit picky on
perfect alignment?

Thanks

Kevin

 

[compound driver 2]

Hi
Go across the bed in three places chuck end middle and tailstock end. Its more important that the beds not twisted than its level. If you think about a lathe on a ship thats rolling level isnt the issue twist is.

Mind you its nice to get the machine as level as possible nad id go for as close to bang on as I could.

Cheers Kevin

 

[Bogstandard]

Kevin Whatsit,

You are not being picky at all, and Kevin Compound has said it all. Twist is the killer, not only for turning, but wear on the ways and saddle. Also get it as rigid as possible. I installed mine a few years back, just after the bed was refinished, and check it for movement every few months. It hasn't moved a badgers nadger in all that time. But if it did, I would investigate to find out why.

John

 

[dwentz]

Yes I agree check for twist. You will find that it will move around with time, and temp. I have been amazed at how much my large lathe moves with temp. Humidity also effect how level my milling machine is when setting on a wooden support. Get it close, and come back in a week or so and recheck. Things have a tendency to settle in over time.

Dale

 

[Circlip]

This question should probably go in the Q & A section but has anyone on the site given any recommendations with details for the construction of a workbench to support the lathe, material sizes,where the supports should be and thickness of the top? It's better to find this out before the setting up stage than try to chase levelling problems. Not suggesting Whatsit or anyone else has got the dimensions wrong but it's worth asking? Ian

 

[tattoomike68]

My smithy is mounted to a wood deck on a large steel cart on casters that was made to hold Caterpillar tractor engines. So its impossible to level it.

Yes I agree check for twist. You will find that it will move around with time, and temp. I have been amazed at how much my large lathe moves with temp. Humidity also effect how level my milling machine is when setting on a wooden support. Get it close, and come back in a week or so and recheck. Things have a tendency to settle in over time.

Dale

Thats good advice get it as close as you can and check it again after you have run it a while. its bound to settle a bit.

 

[BobWarfield]

Continuing on the theme that it isn't the level, it's the twist:

I've seen posts where folks were actually slightly un-leveling their lathes to remove twist. With a small lathe, you have to have the lathe rigidly bolted to a sturdy framed bench to do this.

I'd start out making it as level as you can, and then turn to the next stage of lathe tuning. That involves getting your tailstock set so you're not machining a taper. Anything residual you can't get rid of after that is a headstock alignment or way twist issue. Track down which and make adjustments. Many lathes also have provision to adjust the headstock alignment relative to the ways.

Lastly, these things don't stay adjusted! My mill easily moves out of tram, and I recently noticed my tailstock had moved slightly. What that means is you need some idea when to readjust these things. I like to tram the mill at least before every new project, sometimes more if I notice an issue. The lathe I fiddle with less often, but I still keep an eye on it.

Cheers,

BW

 

[rake60]

A friend of mine once worked for a company who had a 16 foot long lathe.
The building had been expanded before they bought that machine.
The headstock end was anchored to the concrete of the original building floor.
The tailstock end was securely anchored to new floor...
The original floor was poured 40 years ago when concrete was less expensive and
the new floor was made to current minimum code.

As the seasons changed the lathe's slight taper would reverse directions.

It's defiantly all about the twist...

Rick

 

[Powder keg]

You can make a neat gauge to compare one end of the lathe to the other. I haven't made one yet, maybe this would be a good opportunity? I'll try to whip one out fairly quick. They are easy to make and supposed to be really accurate?

Wes

 

[BobWarfield]

No discussion would be complete on lathe leveling without mention of "Rollie's Dad's Method":

http://www.neme-s.org/Rollie's_Dad's_Method.pdf

RD's Method is a way to measure how far out of alignment the spindle axis is with the ways.

Worth a read!

Best,

BW

 

[whatsit]

Thanks everyone.

The ship analogy is what I was thinking about too. I guess technically you could mount
the lathe to the wall and as long as the ways are parallel and straight you should be able
to make an accurate cut.

I checked it at 5 points across the ways and 3 points from headstock to end of bed
lengthwise. It was the same reading at each point.

I agree with checking them out periodically. I do just as Bob, tram my mill before each
project. Sometimes just fiddling to get it just a bit closer is just as fun as the project.
I'll be trying out Rollie's Dad's Method when I get home in the morning.

The bench is made of steel backup battery cases for a telephone switch office
stacked 3 high on 1200lb capacity leveling feet. Top is a 3 1/2" thick glue lam beam
planed flat both sides. Weighs about 525lbs without the lathe, tooling and materials
in the stand. I love these for benches you can drop a big block on it and it won't even
notice it. And the best part is they were free. I will add a picture tomorrow.

Thanks again to everyone for your responses. I must say I wouldn't be this far into
this hobby/obsession if it wasn't for the folks on sites like this.

 

[compound driver 2]

Hi
Once you have the lathe level run a test bar in the three jaw. I use a lump of EN1A about 2 inch dia by about 12 inch long. mount it in the three jaw with a good 9 inches out of the chuck dont use the tail stock just take a full length cut on the power feed of no more that 1-2 thou. You may have to do this a few times to remove run out. Once the bar is cutting round use a good micrometer that you have had calibrated and measure at three points along the bar. Any tapper will show.
My big Dean Smith and Grace is checked like this every month or so and it certainly pays dividends. Both my Colchesters have not moved in 10 years past contraction in cold weather.
All my machines are on the makers tables and are rawl bolted (red Heads) to the floor. The workshop floor is a floating slab of concrete 14 inches thick. thankfully I didnt have to lay the floor.

I have just bought in a big turret mill thats had to have a plinth made in the side room, the guy that laid the concrete set in two lengths of I beam for the bolt downs. Dont half look solid.

Cheers

 

[whatsit]

I ran the biggest rod I had 1 1/2" aluminum in the lathe this morning everything
looks to be running true. Thanks for the help.

Here's a couple pics of my battery can workbenches. These are stacked with
batteries up to 8 shelves high at my office. Each battery weighs 180-250lbs.

These are the smaller ones only 125lbs per shelf. We stacked them 9 high and
anchored them to the floor at a friends shop for tool and material storage.

These are the big ones about 200lbs per shelf. The casters give it a bit of wobble
but it doesn't affect the mill on top.

 

[compound driver 2]

Hi
That looks a good solid setup. I have to say I do like the old American lathes always look like theres not much will get past them. I still wish I had our old Logan now that was a superb lathe.

Cheers Kevin

 

[Bogstandard]

Bob,
With the lathe bolted down tight and showing the same level all along, just try leaning say on the tailstock and see what happens. Not so much the the very big beefy iron, but the smaller variety. It will most probably throw the levelling way out.

We were always taught not to put any pressure anywhere on the machine while it was cutting. The only things you should touch are the setting dials and control buttons. It used to make my blood boil when I used to see an operator with an auto cut on, with his arse leaning on the drip tray by the tailstock, rolling a fag.

I am sure none of us on here lean on the tailstock or headstock looking at the cut as it progresses. A bit difficult with the tiny machines, but you know where I am coming from.

John

 

[chillybilly]

Anybody idea where in the UK tool holder screws can be purchased ? or is it a case of making your own .I need them in M8 thread ....Thanks in advance ...