Why level machines in the shop?

[Adam Levitt]

I hear lots of talk of people leveling their machines in the wood shop. Except for a sliding table saw which may use gravity to keep the slider working properly I can't understand the importance of this.
In a jointer, for example, as long as the piece of lumber is sitting correctly relative to the cutter block and infeed/outfeed tables, why does it matter if it's level? Same for an assembly table, as long as it's flat and you're measuring everything relative to its surface why does it matter if it's absolutely level?

Hopefully I'm not missing something very obvious, if so please feel free to ridicule me, but just a bit :)

[Randy Rose]

My t/s , router table , work bench and planer are level and set at the same height , in a small shop there are times when one object serves as the outfeed surface for another.

Recently built a platform bed, during mock up and fitting one rail was on the bench and the other on the t/s. JMO

[Adam Levitt]

Randy, that definitely sounds like a good reason

[Phil Mueller]

I like the surface to be level for assembly. Given my joinery skills (still new at this), it's quite possible assemblies can rack when clamping. I suppose I could just know the level bubble needs to be half way across the right line, for example, but easier if I can just reference the level to a centered bubble both vertical and horizontal.

[John K Jordan]

I know one very important reason, perhaps not so much level as in "perpendicular to gravity", but as "in a perfectly flat plane". If all support points are not in a perfect plane the machine can warp causing inaccuracies in the cut.

The most glaring example of this is in a lathe. It is important to check the alignment of the headstock and tailstock by putting point centers in each and see if they line up perfectly. It is common for them to be off by a small amount which can cause severe vibration and other problems. Believe it or not the cast iron bed can easily bend, a common reason for misalignment is one leg out of level.

When setting up my little machine shop I read of a machinist who demonstrated this to visitors on a huge lathe by letting them press on the bed with a finger which caused a deflection in a test indicator on the piece!

Before I found out about the importance of leveling I had a terrible problem with one wood lathe being out of alignment. I resorted to adding thin shims on the ways and using a magic wand but it was never perfect. I finally brought it into perfect alignment with a 1/2 turn of one leveling foot.

I had a similar issue when setting up my cabinet saw. A precision level showed a slight twist in the table surface from front to back until I shimmed one corner of the base. (It didn't have leveling feet.)


JKJ

[William Adams]

Precision has to start somewhere.

[Al Launier]

Precision has to start somewhere.

Agree! And that somewhere should start with a positive frame of reference.

If one has a mindset to do quality, precision work, then in my mind that starts at the beginning. In woodworking, or any other similar endeavor, that means having a level & square set up from which work begins and ends. Why tolerate an out of plumb surface or equipment to work or measure from? If one's mind accepts inaccuracies in the tooling/equipment to begin with, to me that would make it easier to accept the same result in the finished product.

[glenn bradley]

as long as the piece of lumber is sitting correctly relative to the cutter block and infeed/outfeed tables, why does it matter if it's level?

This is correct. Relative angle is what is important to the operation. I level all my machines because I am on a not-level surface and a level chassis simplifies alignment. I even have marks on the floor for those tool that do move so that I land them in the right spot without having to worry about them teeter-totering or worse, settling themselves and pulling things out of alignment. Nothing we do with our machines is a requirement. If you are happy and its working, its right for you.

[Erik Loza]

Not so much for the sake leveling, but more in regards to "firmly planted to the floor along as much of the machine base as possible" (which we should strive to have level, anyhow), I've seen vertical bandsaws practically walk across the shop if they weren't level AND in full contact with the floor.

Erik

[Kevin McCluney]

If for no other reason, it keeps things round items from rolling off the table top. And similar to what previous posters have written, it allows two surfaces to be made co-planar much easier (for example, the table saw and a free standing outfeed table).

[Jamie Buxton]

I suspect that many people say "level" for meaning "doesn't rock", not meaning "horizontal".

[Steve Peterson]

My shop has always been in a garage, so the best I can hope for is flat, relative to the tool next to it. I think my garage has 1/8" per foot slope or 3" across the entire 24'. I don't see myself getting a sliding table saw.

Steve

[jim mills]

Precision has to start somewhere.

Quote of the day!

[John Donhowe]

My shop is in the garage, too. In my case, lack of precision is more likely due to operator errors than not having a working surface precisely perpendicular to the gravitation vector, so my efforts are toward improving those shortcomings.

The one thing I can't do is perform the "nickel test" on my table saw- the nickle rolls off!

[Mike Cutler]

I don't go OCD about "Level", but in a small garage shop all the tops need to be in the same plane. My jointer, shaper and both table saws are in the same plane.

You will naturally try to level a machine. Your eyes and hands will be constantly trying to correct for the deviation, and you'll be uncomfortable using a machine that is not somewhat close to level. You'd be stunned at just how close to level you can get a machine without using any type of aid. My bandsaws, planer and CMS are set to "level-ish".

[Adam Levitt]

I like levelish and if it's really off level it could be good training for zero grav.

[Cody Colston]

My machines are only as level as the concrete floor in my shop. Never even considered putting a level on any of them. None of them "walk" around when running, though.

[Allan Speers]

So my pencils & marking knives don't roll off. :)

[paul cottingham]

The main reason is because a lot of woodworkers are really, really, really obsessive (I was going to say "anal-retentive" but was pretty sure that violated the TOS) about such things.

Seriously. Oh, and because then its easier to support stock.

[Bill McNiel]

"My t/s , router table , work bench and planer are level and set at the same height , in a small shop there are times when one object serves as the outfeed surface for another."

(Still don't know how to do that bubble thing for quoting someone else's wisdom or logic.)

[Chris Kiely]

I level them pretty close for a variety of reasons but mostly because I'm particular - it's not quite right if it's not level.

But only within reason. My jointer is on a busted mobile base so that the only way that it works is when it's not level. It's too much of a hassle to swap out the base so I'm cool with it :)

[Ben Rivel]

Being that pretty much all my tools are on wheels and are moved around at least a bit while they are being used there is no leveling for me.

[Martin Wasner]

The only things that I've leveled on the shop is the widebelt, it's out feed table, and the panel saw. Everything else is just sitting on the floor. The out feed tables on table saws are shimmed so they plane out with the saw, but I if they are level it's just coincidence. Everything else is shimmed so they don't rock.

[Paul McGaha]

My shop is an attached 2 car garage. I'd guess my floor slopes about 3" to 4" in about 20'. I level my machines and bolt them down. I have a construction background and stationary equipment is generally required to be leveled and bolted down. Pretty much always.

Besides I just like the machines square to the shop, level and bolted down.

PHM

[Prashun Patel]

What's this 'level' term I keep hearing about?

I'm with you Adam and Eric. As long as it ain't rockin' or rollin', "ish" works for me.

[David C. Roseman]

I know one very important reason, perhaps not so much level as in "perpendicular to gravity", but as "in a perfectly flat plane". If all support points are not in a perfect plane the machine can warp causing inaccuracies in the cut.

The most glaring example of this is in a lathe. It is important to check the alignment of the headstock and tailstock by putting point centers in each and see if they line up perfectly. It is common for them to be off by a small amount which can cause severe vibration and other problems. Believe it or not the cast iron bed can easily bend, a common reason for misalignment is one leg out of level.

When setting up my little machine shop I read of a machinist who demonstrated this to visitors on a huge lathe by letting them press on the bed with a finger which caused a deflection in a test indicator on the piece!

Before I found out about the importance of leveling I had a terrible problem with one wood lathe being out of alignment. I resorted to adding thin shims on the ways and using a magic wand but it was never perfect. I finally brought it into perfect alignment with a 1/2 turn of one leveling foot.

I had a similar issue when setting up my cabinet saw. A precision level showed a slight twist in the table surface from front to back until I shimmed one corner of the base. (It didn't have leveling feet.)


JKJ

+1. Late to this thread, and I'm surprised John is the only one who has made this point. Our big machines have heavy components of disparate sizes and weights that are not uniformly distributed around the machine's center of mass. Engineers design large woodworking bench machines to sit level to the ground plane, and if they don't, stress is induced in the wrong places and can cause bushings, bearing and belts to wear prematurely, and cast iron to deform. I do agree with others that whether the top "working surface" of a machine is perfectly level to the ground plane may not be critical to producing good work. And, for that matter, the working surface can sometimes be made level to the ground even though the rest of the machine is not. But it is a good place to start in recreating in our shops the correct alignment and equilibrium within the machine that it is designed to have. And sometimes our work is affected, as John notes. The lathe is a good example. If all four feet are not adjusted to be in the same plane, it can easily twist the cast iron or steel bed ways just enough to throw the headstock and tailstock centers out of alignment. In a heavy table saw, twist induced over time in the cast iron top and wings can affect precise cuts.

[Garth Almgren]

(Still don't know how to do that bubble thing for quoting someone else's wisdom or logic.)
I just use the "reply with quote" button. Much easier than remembering the quirks of BBcode. :)

[Adam Levitt]

+1. Late to this thread, and I'm surprised John is the only one who has made this point. Our big machines have heavy components of disparate sizes and weights that are not uniformly distributed around the machine's center of mass. Engineers design large woodworking bench machines to sit level to the ground plane, and if they don't, stress is induced in the wrong places and can cause bushings, bearing and belts to wear prematurely, and cast iron to deform. I do agree with others that whether the top "working surface" of a machine is perfectly level to the ground plane may not be critical to producing good work. And, for that matter, the working surface can sometimes be made level to the ground even though the rest of the machine is not. But it is a good place to start in recreating in our shops the correct alignment and equilibrium within the machine that it is designed to have. And sometimes our work is affected, as John notes. The lathe is a good example. If all four feet are not adjusted to be in the same plane, it can easily twist the cast iron or steel bed ways just enough to throw the headstock and tailstock centers out of alignment. In a heavy table saw, twist induced over time in the cast iron top and wings can affect precise cuts.

David that's a great point. I wonder what the tolerances are for these machines.
BTW, when I meant not level I did not mean sliding around the shop not level, but maybe one or two degrees off.

[John Gornall]

There may be more to this “level” than you realize. I have long experience with installing machines and process equipment. The machine was assembled at the factory on a flat, level, reference surface. Then it’s dropped on an uneven garage floor on a mobile base. We read in these discussion forums about the person that then gets out a straight edge and finds, for example, that the out feed table on the new jointer/planer is out of alignment by 6 thou. Then there is a rant that the machine is no good, the company won’t come out and fix it and then it’s taken apart and the new owner spends months trying to fix this 6 thou. I recall one post I read where the machine was never used – the owner gave up. Never even put wood through it. But maybe, and I agree all machines are different, if a wedge was put under one leg and tapped with a hammer a couple of times that 6 thou thing would disappear. “Level” doesn’t just mean the table looks good with a level on it. At the factory, on the assembly table there’s 25% of the machines weight on each leg. But on your garage floor perhaps 80% of the weight is on two diagonal legs and the rest on the other 2.

[Eric Schmid]

I have an old Rockwell Contractor's saw. It sat on various concrete floors for many years the weren't level, although always firmly planted. I never thought much of it until I tried to bring it into alignment with an out feed table, which is dead flat and level. Using some big leveling feet I got it level only to find that one of the feet floated. The frame was racked, probably from being reassembled on a not level surface several years ago when I rebuilt it. I guess it does matter for some machines.

[Shawn Pixley]

Everything is on wheels on a garage floor; there is no "level." There is however Flat and Planer.