Anchor 2200# lathe to concrete floor or not?

[Danl]

I've been researching whether or not it is a good practice to anchor my Nardini 1440 lathe to my concrete floor. The manufacturer thought it was, but as I read a bunch of threads in various forums on this very question, it almost looks like more people would not (or do not) anchor their lathes to the floor.

I'm thinking about providing 1/2" thick "L" brackets to the ends of my 2 bases before moving the lathe into my shop so I can anchor it using drop in anchors at a later date if needed, just in case.

Thanks for your opinions.

Dan L

[Bob Ford]

You live on the pacific rim. Will you anchor before or after the earth quake. After the earth quake your lathe might just be scrap and no need to anchor.

Bob

[lakeside53]

Depends. There are two reasons to anchor -

1) It might tip over - like in an earthquake zone or some idiot with a forklift.

2) You need to differentially pull down or push up on some of the "hold downs" to get a straight ways. Many quality lathes have a two-thread insert at the hold points for this purpose.

Me? Na... I did with my little lathes, but my 5000lb Howa is quite happy "sitting there" and adjusted "level and true" with just "push ups". It would have been easier to have adjusted it with hold-downs in place as 8 points of adjust/level make it really hard to not lift weight off other "free" points.


For those that don't know what I'm taking about, most manf of larger lathes recommend deeply embedded threaded studs to mount the lathe on )better have a good template), and then a threaded sleeve screws down through the casting and over the stud. This way you get to pull down and push up at any point.

[flylo]

I'd anchor it as part of the leveling process. Why skimp now?

[The Artful Bodger]

Lathes do not like earthquakes! After the earthquakes in Christchurch I saw several lathes for sale with 'minor damage to carriage handles'!

If earthquakes are a worry I suggest bolting down to a heavy plate which would give stability and allow the lathe to dance around a bit without falling over which would be better than trying to defy the forces of nature by bolting down to a slab of concrete.

[EddyCurr]

My 2,200 lb Jet GH-1440W equivalent perches on Royal Machine Mounts. The floor protection they offer is important to me (and they level easily); but if this is not a consideration in your circumstances, then spend the money elsewhere.

I do not use the lathe aggressively enough to cause it to want to move around on its own. Seismic activity isn't (or hasn't been) a consideration in my region. No perceived need to anchor.

Edit: I see Royal touts their mounts as meeting OSHA requirements for preventing "walking", doing away with the need for anchoring.

.

[chipmaker4130]

To get to the point, yes I would bolt it down. The size & weight of your lathe aren't necessarily the things to consider. More relevant is how hard you might work your lathe with regard to its capacity. I have a 'medium' size lathe for a home shop, a 13" Sheldon with a 6ft bed. Bolting it to the floor not only made leveling easier via 'push-pull' as mentioned above, but it stays in trim for long periods. The stability of the floor is a prime consideration here. The main thing, though, is I can push that lathe to capacity and it performs very, very well, easily taking .100 doc cuts in high-carbon steel. I've even done .200 doc passes with the feed at minimum speed, but that's not fun as it results in a continuous ribbon of swarf to deal with. Before the anchoring, attempts like those resulted in enough vibration and chatter to almost leave one toothless! So if you have a heavy lathe and only work in small, slow steps maybe securing it to the floor isn't as big a deal. I'd do it anyway.

[BCRider]

I'd bolt it and use the bolts as leveling AND clamp down jacks by using nuts and washers both below the lugs and above. Leveling is nice but really the requirement for the lathe bed is straight, true and twist free. Accurately level is only on incidence of "straight, true and twist free". When I set up my lathe on leveling nuts I used a basic construction level to get it level by that tool but then from there I relied on test cuts and test indicators to true the bed for straight and twist free and then used those same indicators to align and level my tail stock. Using the combo of jacking nuts and hold down nuts made doing this alignment rather easier than I'd thought.

There's also the case of the times where you're doing a seriously heavy hogging off cut. If the load on the machine is sufficient to twist the bed enough to raise one corner then it's likely that chatter or other poor results will occur. Hold down bolts can take away that sort of concern.

On the other hand if you're asking about simply bolting it to the floor I'd suggest you don't just clamp it down to the floor. If YOUR floor is totally flat and planar over the area needed then it's a sure case of "good luck" rather than "good planning". I've yet to find a floor that is flat and true over more than a small patch between other portions that are wavy, warped and generally mountain range like in terms of what we would consider acceptable for truness of a lathe bed.

[Paul Alciatore]

It depends on what level of accuracy you want to work to.

If a 0.002" taper in a foot is OK, then you probably do not need to anchor it or do any leveling and other set-ups. I have worked with lathes like this and you can do a lot of work on them.

But if you want to do real precision work, then you do need to do a proper leveling and set-up to get it to turn cylinders without bad tapers. But all that work is going to be completely lost if it moves even a fraction of an inch on a concrete floor. Concrete is flat to +/- 1/4 inch, at best. If you move the feet of the lathe or of the table it is mounted on even a short distance, all four feet will be sitting on an entirely different level than when you leveled it and set it up. So the entire leveling and set-up procedure will have been for naught and you are back to 0.002" tapers or worse.

1. Forget wood tables. Wood breathes. Use one kind of metal for the table or other supports so the expansion coefficient is the same. Within reason, different alloys should be OK, but just one kind of metal (steel, aluminum, etc).

2. The feet should have a fairly broad area, at least 0.5" square. More is better. This distributes the load over an area of the concrete and not just a single point.

3. LOCK it down in ONE and ONLY ONE position. Don't ever let move, even a small fraction of an inch.

4. Then do the leveling and set-ups that follow that to eliminate tapers.

In earthquake country I would definitely anchor it.

[EddyCurr]

I do not use the lathe aggressively enough to cause it to want to move around on its own.

ie: no heavy, unbalanced faceplate work and no big interrupted cuts.

0.120-0.140" cuts in 4140 are uneventful with this machine on the Royal mounts. Danl's Nardini is the same weight as my machine and the more capable lathe - I thought long and hard about bidding on a Nardini 1440 a few years ago.

Incidently. It may not be apparent, but the Royal mounts have a (captured?) inner platform segment that rises for leveling as the square-headed central bolt is turned. There is a nut that turns down the central bolt to clamp the lathe foot to the inner platform.

.

[boslab]

What about anti vibration feet they use on big compressors.
Mark

[BCRider]

I missed the bit about you having Royal mounts. In that case you could likely get away with just marking the floor to ensure the machine doesn't walk during cuts involving vibration from being interrupted or for any other reason. Just keep in mind that you ARE relying on the weight of the machine to hold itself down. But as long as that works you'll be ducky.

The use of the jacking feature is still going to be very much needed because again floors are seldom planar over 4 or more points. So some way to bring the lathe into proper tuning for straight and twist free is needed. And that's where the jacking feature comes in.

[john hobdeclipe]

Here in North Texas, we have a very unstable soil (Montmorillonite Clay) that shrinks and swells with changes in moisture level. Houses and shops tend to have a dry season configuration that is totally different from the rainy season configuration. My own shop concrete slab has moved and heaved quite a bit in the past 13 years, and is not very level now, nor is it very consistent in its lack of levelness.

So in my case the only machine that is bolted down is the drill press, and it is not bolted down tightly.

Depending on the stability of your soil and your earthquake risk you may consider bolting your machine to the floor, but leaving a bit of room for movement. I once saw some pallets of high$$$$$ computer equipment that used a short (2") length of rubber air hose around the bolts that held the servers to the pallets, to give a bit of shock and movement protection. Perhaps you could do somewhat the same thing, giving a bit of freedom of movement but keeping the machine from tipping over.

[EddyCurr]

What about anti vibration feet they use on big compressors.
Mark

Like these Royal Machine Mounts ?

Or something different.

.

[BCRider]

Here in North Texas, we have a very unstable soil (Montmorillonite Clay) that shrinks and swells with changes in moisture level. Houses and shops tend to have a dry season configuration that is totally different from the rainy season configuration. My own shop concrete slab has moved and heaved quite a bit in the past 13 years, and is not very level now, nor is it very consistent in its lack of levelness.......

If I were in an area with that sort of conditions and were there for the long term I honestly think I'd cut away a portion of the floor and dig it out and pour in a free floating slab that was thick enough and reinforced enough that it floated in place so the lathe mounted on it had a consistent bed.

Another option I could see would be some sort of frame for the lathe to sit on which connects to the floor with only three points so the lathe is never sitting on two diagonal points and causing a twist in the bed. It would not be as rigid but at least it would remain consistent.

It must be hard to keep the garage and basement floors from cracking too. And any concrete drive ways.