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Seismic Restraints for Lathes??

dazz

Stainless
Joined
Aug 20, 2006
Location
New Zealand
Hi
Does anyone have any guidelines or standards applicable to the seismic restraint of machine tools (eg, my lathe)?
I have found stuff on HVAC and buildings, but not machine tools.

The HVAC stuff assumes that plant will be mounted on a skid that is then supported by sprung restraints. That isn't going to work with a lathe.
I am looking for a DIY solution. The cost of shipping a box of chunky metal hardware to here makes that option too expensive.

I have a 20cm thick concrete floor but the lower 10cm is not steel reinforced. The restraints need to limit lateral and tipping motion but have sufficient give to avoid breaking the machine if the floor cracks/flexes.

Dazz
 
Hi
Does anyone have any guidelines or standards applicable to the seismic restraint of machine tools (eg, my lathe)?
I have found stuff on HVAC and buildings, but not machine tools.

The HVAC stuff assumes that plant will be mounted on a skid that is then supported by sprung restraints. That isn't going to work with a lathe.
I am looking for a DIY solution. The cost of shipping a box of chunky metal hardware to here makes that option too expensive.

I have a 20cm thick concrete floor but the lower 10cm is not steel reinforced. The restraints need to limit lateral and tipping motion but have sufficient give to avoid breaking the machine if the floor cracks/flexes.

Dazz

What size is the lathe? But going with a smallish machine (under 3Kg), then some "Z" straps made from 12mm x 50mm bar, bolted to the floor with suitable anchors, placed over the mounting pads with a little clearance should do a decent job for "normal" quakes. Place them so they're not a tripping hazard.

If the Big One hits you'll be worrying (or not) about other things...
 
Heh, and of course I meant 3K Kg, but a small machine like that shouldn't be an issue to constrain. Generic steel bar, heated low red to make it easy to bend. The most important thing may be the anchors, you'll have to figure out what's available and is easiest to install, yet has good holding strength. Min 10mm bolt, I'd think.
 
Hi
Does anyone have any guidelines or standards applicable to the seismic restraint of machine tools (eg, my lathe)?
Japan will have yes. I wasn't "doing" lathes at the time.

Installing International "Gateway" telco switchgear, rather, KDDI, Tokyo. My Swiss-made, Danish-populated 42U rack was already equipped for it. KDDI's FM site already had the attach points in the sub-floor below each rack location. Needed only the drawbolt included for the purpose by the thorough Swiss. At $10,000 USD for the bare rack? It damned well SHOULD have come so equipped, and had done.

California may have much the same, but my server in those earlier days survived the Loma Prieta by virtue of an ignorant bungee cord into the corner of the room I had actually added as a joke.

It wasn't 12 hours before that quake took the building it was in, just South of SFO's gates, right off its foundations, destroyed every OTHER stick of office furniture but the swivel-chairs. Our POP, Fremont district, was unharmed, but I had to get a gen set to it.

Police weren't too happy even granting access until I told them they either let "telephone men" do what WE do, gas leaks be damned, or they could go back to smoke-signals for the next 2 months.

Cable & Wireless were the first telco back on line, too. Three days before we had any others to exchange traffic with, PACBELL included.

There is guidance out there you can adapt if not use directly.

We Telcos had the bad habit of putting our Diesels on ROOFTOPS to keep the complaints about noise and stink down, for example.
 
I'm interested in this thread because there's a decent likelihood of a subduction zone quake about 200 miles West of my location in the next several decades. USGS best estimates are several minutes of continuous strong shaking in my immediate location (soils are crappy). By "strong", 1-2G horizontal accelerations. By way of analogy, have someone dump you out of a hammock about 50 times in rapid succession. That's what building walls will do to you until either you, or they, fall down.

I have been inclined to just let my machine tools fall where they may. I've got a decent quality reinforced concrete slab in the shop, but have not considered it likely I could anchor a 7000lb top-heavy milling machine to it and have the slab survive. Should I be more optimistic, and start thinking about restraints? (That's honest question, not sarcasm.)
 
I'm interested in this thread because there's a decent likelihood of a subduction zone quake about 200 miles West of my location in the next several decades. USGS best estimates are several minutes of continuous strong shaking in my immediate location (soils are crappy). By "strong", 1-2G horizontal accelerations.

got a source for that? the reason i ask is because a mechanical engineer friend of mine mentioned the twin towers were only designed for a 10% safety margin for a 100 year earthquake. i tried to look up what a 100 year earthquake is, depending on location its on the order of .3 to .4 G forces.

If they really expect 1-2 G force accelerations.. very few modern buildings are going to survive.

if you mean to type .1 to .2G force accelerations, that is much more believable.
 
A lathe that size should already have hold down bolt holes in the base. I used drop anchors and 3/8? all thread to make hold down bolts. You could simply mix hydraulic cement and use that to cement studs into the slab.
For some reason people here will complain and say bolting down is a bad idea. If you believe that level the lathe then just finger tight the bolts so it will not move in a quake.
I drilled the holes and set the bolts when I first installed the lathe so lifting it up and over onto the studs was no problem. The bolt sat the tailstock end would have been a problem to drill the slab for if the lathe was in position.
Bill D.

My Harrison m300 13x40 lathe weighs 1750 pounds and has four 12mm bolts holding it up. It is designed to have four 12mm hold down bolts as well. So I would say 10mm hold down bolts would be more then enough.
I used some 1/2" chain with bronze lag bolts to tie down my sisters water heater because the material was free.
 
got a source for that? the reason i ask is because a mechanical engineer friend of mine mentioned the twin towers were only designed for a 10% safety margin for a 100 year earthquake. i tried to look up what a 100 year earthquake is, depending on location its on the order of .3 to .4 G forces.

If they really expect 1-2 G force accelerations.. very few modern buildings are going to survive.
United States Geological Survey and the Oregon State Seismic Safety Policy Advisory Commission. (Added in edit: also Oregon Department of Geology and Mineral Industries.) Published earthquake hazard maps for Oregon. These have the full-on expected acceleration spectra, along with a bunch of numeric parameters that I find impenetrable. (I'm an engineer, but not a geophysical engineer, and this is their bread-and-meat.) Best distillations I can find for the locally applicable magic numbers works out to 1-2G accelerations. Again, soils are crappy in my location.

Location, location, location. The twin towers are not situated close to a major tectonic plate subduction zone with geologically and archeologically proven history of massive (magnitude NINE PLUS, which is ten times more powerful than an insanely distructive magnitude 8) earthquakes. The Juan de Fuca plate is shoving underneath the North American plate and we are about due (based on that history I mentioned) for another rupture any time now. Mean time between major ruptures seems to be about 550 years, sometimes 300, sometimes 700. We actually know to within a few hours the time of the last rupture (26 January 1700), because the resulting tsunami was recorded in Japan and it was note-worthy there because no one there felt any accompanying earthquake. (There is also corroborating evidence based on tree ring counts and isotope analysis from buried forests. The Japanese records just narrow the date down from +-50 years to a specific date and time of day.)

There is decent evidence that the west edge of the NA plate is being pushed east and up due to the friction lockup of the two plates. They've looked at century-old railroad and highway surveys, and it appears the whole area is tilting toward the east slightly. When the rupture takes place, the Pacific coastline is going to move, probably tens of yards, in the opposite direction and it's going to do it in a matter of minutes. Many low-lying coastal locations will end up under sea level simply because the NA plate dropped, not considering the tsunami.

Structure survival? Yeah, it's going to be pretty grim. Most older residential neighborhoods were built when you didn't even have to tie your house frame to the foundation. Downtown Portland still has a bunch of office buildings with cast iron frames and brick infill. DOT went around about 10-15 years ago and tied most bridge and overpass spans to the columns with steel cables to (try to) prevent pancaking, but that's just going to reduce loss of life, not retain functionality.

They really, really are not kidding here when they say you should have several weeks' supply of food and water for your family. Imagine the most intense devastation of the recent Hurricane Michael, but applied to a swath 400-700 miles long and 100-150 miles wide.

About the only good news for my location is that I won't have to worry about the resulting tsunami. The tsunamis are how they discovered this thing repeats every few centuries, because they move enough beach and bury enough hunks of forest to be readily found once you know what you are looking at. But I don't live where a tsunami can reach, even pushing back up the rivers.

Anyway, getting back to the original discussion: Should I be reconsidering my resigned apathy and bolting down my machines?

Added in edit: Here's a lovely quote from a 2015 article in The New Yorker
Kenneth Murphy, who directs FEMA’s Region X, the division responsible for Oregon, Washington, Idaho, and Alaska, says, “Our operating assumption is that everything west of Interstate 5 will be toast.”
In Oregon, I5 is typically 40 miles inland.
 
Anyway, getting back to the original discussion: Should I be reconsidering my resigned apathy and bolting down my machines?

It won't hurt, but to do any good you'd want to study the realistic loads through the machines and floor and be sure your methods won't fail quickly. Maybe that means a two-stage approach, both bolting and an "elastic" (like the steel cables) restraint in case the bolts fail.

My sister live in Portland, on the side of a steep hill. The house basement is very deep, going to bedrock, and she assured me that an engineering analysis showed the house would be stable under earthquake conditions. Still hasn't made me less nervous...
 
Added in edit: Here's a lovely quote from a 2015 article in The New Yorker [...] In Oregon, I5 is typically 40 miles inland.

Kenneth Murphy, who directs FEMA’s Region X, the division responsible for Oregon, Washington, Idaho, and Alaska, says, “Our operating assumption is that everything west of Interstate 5 will be toast.”


yes, i'm well aware of that. i have not personally attended the meetings but we've been told that bainbridge island is sort of last on the priority list.

i'm just having trouble imagining 1-2G forces. figured that was a typo. maximum ground uplift was usually .3 to .4 G for a M 9 earthquake.

1-2G forces side to side exceeds the friction coefficient for a large cement slab on top of the ground. so you throw some light weight steel framework on top of that, it might survive. as it sinks...

but 2 G force means soil liquefaction everywhere as far as i know.
 
Empirical data here. I live on the Ring of Fire- Alaska- and in the last three years, have sat through a 7.1 and a 7.2 shaker.

Zero damage. Both were 30+ seconds long, plus aftershocks. Didn't even knock any spray cans off of high shelves. The only trace was several of my ball-bearing tool chest drawers rolled open. :D

Now, those were low sevens, and a low eight would be ten times more powerful. But it's also worth noting that this area withstood (for certain loose terms of that definition :D ) the Good Friday Earthquake, which was something like a nine point two, and lasted something like five minutes.

Damage was extensive, of course, not even counting that from the resulting tsunami. But, if you look at some of the pictures, you'll see largely intact buildings, whose major damage was largley due to the ground underneath them collapsing.

In other words, it wasn't necessarily the shaking that did them in (although that did indeed cause considerable damage) it was the fact the ground beneath them essentially liquified and sloughed.

And in that kind of case, it doesn't matter how well you've anchored your lathe, or how deep your slab is. It's gonna go no matter what.

Personally, if we have an 8.0 or greater- which could literally happen at any time- I suspect many of my machines will get damaged- especially stuff like the drill presses and other tall, thin ones. But I suspect I'll also have plenty of other problems to worry about, like severed gas lines, cracked walls and foundations, loss of power, and many other things.

You can prepare, but you can't prepare for everything, and at some point the preparations get in the way of day-to-day living.

Doc.
 
major damage was largley due to the ground underneath them collapsing.

In other words, it wasn't necessarily the shaking that did them in (although that did indeed cause considerable damage) it was the fact the ground beneath them essentially liquified and sloughed.

This was really driven home, Loma Preita quake. I was just leaving a realtor's office, East Bay, after scouting office space when it hit. Asphalt carparks and the highways in sight rolled like waves on the ocean. Then they settled back. Right where they had been. Burlingame, our existing office building moved just under a foot off its foundation, but remained intact. A sugar company HQ, same road, went to junk.

My lodgings, San Mateo, right close to the bridge, fake adobe & stucco, nary even a cracked wall. "The Vans" where I'd hang out, end of a long day, the barman (owner, actually, Loring was, but I didn't know that, then) said he lost exactly ONE bar glass. And it was one he threw on the floor in sympathy.

His bud, Redwood City, had been totally wiped-out. Building, mirrors, furniture, decor, barware, and bottled booze.

The difference? The Vans [1]- and my lodgings - sat atop the hard rock of the San Brunos.

Redwood City was on an alluvial flat. Which - for all intents and purposes- just liquified.

See this past month, Palu, Indonesia. Worse yet:

Indonesia using helicopters to spray disinfectant over areas with dead bodies from earthquake and tsunami | The Independent


[1] The Van's History
 
Dazz have you considered just taking up a safer occupation? This whole lathe buisness seams to be getting way too dangerous, next you will realise the oils toxic and the metal cuttings are sharp.
 
Solution: put each machine in it's own sea container. Equip each container with gps so you can know where to dig them up :D

Might be better to equip the shop with an explosive blow off roof and a rocket propelled ejection seat to blast you out of there when the machines start sliding around the floor. If it saves even one life, it's worth it ;)
 
I'm interested in this thread because there's a decent likelihood of a subduction zone quake about 200 miles West of my location in the next several decades. USGS best estimates are several minutes of continuous strong shaking in my immediate location (soils are crappy). By "strong", 1-2G horizontal accelerations. By way of analogy, have someone dump you out of a hammock about 50 times in rapid succession. That's what building walls will do to you until either you, or they, fall down.

I have been inclined to just let my machine tools fall where they may. I've got a decent quality reinforced concrete slab in the shop, but have not considered it likely I could anchor a 7000lb top-heavy milling machine to it and have the slab survive. Should I be more optimistic, and start thinking about restraints? (That's honest question, not sarcasm.)

If you are in the immediate vicinity of the cascadia rip...machines falling are going to be very low on the list, like not even on it lol.

They have built it up to being a cataclysmic disaster, but will it be? I really don't want to find out lol.
 
Hi
It's a Nardini MS350. 1m between centres. I don't know the weight but probably close to 1,000kg.
Dazz

If you use the anchor bolts specified by Nardini they will withstand any foreseeable seismic forces. Mine, on the other hand, just sets on the floor.
 
If they really expect 1-2 G force accelerations.. very few modern buildings are going to survive.

if you mean to type .1 to .2G force accelerations, that is much more believable.

Hi
1-2G forces are definitely plausible. In the 6.3 Christchurch earthquake, peak accelerations measured at 2.2g. People and things were thrown into the air.

Modern buildings here are designed to be survivable in a major quake. That is not the same as remaining serviceable. After a major quake, buildings get pulled down.

Dazz
 








 
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