Should every machine tool be bolted to a concrete floor?

Following from my popular recent thread on laying a concrete slab for a new workshop, I've started pondering what the best practise is with regard to bolting machine tools (typical hobbyist machine sizes: Myford/Colchester/Tom Senior etc to a concrete floor?

I vaguely remember reading that it's preferable to do so but have not found a convincing reason why. Surely the machine's weight will prevent any 'drifting' off location?

Any advice gratefully received.

It's one of those things that is best to do, but lots of people don't bother, with no harm done.

A machine that is bolted down can't tip over, is the main reason for doing so. Lathes and mills can be rather top heavy so in spite of their weight, can be tipped over if given a nudge, say by another piece of machinery being moved or the like.

It also seems to dampen vibration if they are fixed down. And makes sure they can't gradually move about the floor from vibration over the years. This movement can affect machine alignment as concrete floors are never flat to Schlesinger limit sort of tolerances.

For the sake of drilling a few holes with a masonry drill and dropping a few anchor bolts down the holes, I would go ahead and do it.

The main thing, a very important thing, when bolting down machinery either to the floor or a bench is to sit it in place then go around each foot with a feeler gauge and find if one or more feet have a slight gap under them. If so, the gap/s need to be firmly filled with a shim of suitable thickness. If you don't do this, when you tighten the bolts down, the machine bed will be twisted, throwing it out of alignment and putting it under permanent stress.

Have fun in your new workshop!

Edited By Hopper on 18/07/2018 00:32:22

None of mine are although i did have to modify the big lathe cabinet to make it less likely to topple over as its footprint was very narrow . My smaller lathe and mill are on home built rolling cabinets and i just fixed them to a couple of wall studs with some angle brackets - haven't moved in the last five years ! With the mill wind the table out to one side and give the head a nudge to see if it wants to topple easily towards the overhanging table side , if it doesn't feel nice and steady bolt it down - my stand has a big footprint so is pretty stable .

Neither my lathe nor my milling machine is bolted to the floor. My milling machine is bolted to a heavy cabinet with four adjustable feet. A friend welded together a stand for my lathe, I have had both for many years and have never had any of them move (hard rubber under the feet).

Thor

I have worked in factories and there is no fixed rule a 20 tonne micro jig borer was sat on rubber pads under 12 inch square by 1 inch plates with a dimple for adjusting screws but not bolted down then a small offhand grinder had to be bolted down. You have to look at what if. If you have a mill for instance with a long bed and you load a large vice and a piece of steel to one end and traverse it out ie if you were boring the side of the block with a 90 degree head is it stable. I have seen a Bridgeport turret mill just like this and although no one was injured the cost of new lead screw castings traverse motor and the bench and toolbox was immense. Look at the machinery is it stable or do you need to bolt it down to get a stable adjustment of the spindle or bed.

David

Edited By David George 1 on 18/07/2018 08:03:39

One thing I would definitely bolt down would be the drill press. These can turn quite nasty if the drill bit catches when drilling something like the end of a long piece of steel that you are firmly holding. The job stays still and the unbolted drill press starts to spin around. Ouch. Also a drill press can tend to tilt toward the operator if too much downward pressure is applied to the handle when drilling with a blunt bit etc.

👍

I have done the waltz with a drill press once or twice . My first workshop under mums house had bricks as pavers around the bench but hard dirt everywhere else , my brother scored an old drill press for me and at firts it just sat on the dry dirt . Aftrer the first incident ilashed the head up to the floor joists with rope as being 13 that was all a could afford ! I'm still here so must have worked 😄

XD 351, diff with no money, reminds me of me dad who had little tools and even less money........

he'd be shocked to see what's available these days.......have seen some machine that were double sided sticky taped to the floof......

guess it wouldn't have stopped the Bridgeport disaster, DG 1 mentioned.......

Yes. Smaller ones are light and bolting-down, at least to a workbench, is effectively essential.

For ordinary hobby-sized lathes and mills, I think you takes your choice. I've never bolted mine down, and I fear the work involved might actually be counterproductive because of the risk of introducing (more? ) twist through the forces applied.

Part of the industrial bolting down process would be to shim the machine level then tighten bolts and check level then grout the gaps left, I think the modern way is to use epoxy to glue, gap fill and bolt down. Even if you skip the levelling, bolting without stressing is important and controlling a usually top heavy machine could save you from injury and the machine from damage. I had better go and bolt my machines down🙄

Mike

I have bolted my Bridgeport to a custom built frame which extends the footprint, the frame is fitted with anti-vibration/levelling pads which complete the protection.

...every...

There is, as they say, an exception to every rule.... often more than one.

None of my machines seem to stay in one place long enough to bother bolting them down

My X2 mill, SC4, adept shaper and pillar drill are all bolted down either to built in benches or in the case of the SC4 to a matching stand that's attached to the floor. All the smaller machines (grinders and mini lathe) are free standing.

Neil

If you have a lathe like a Bantam with a pedestal each end firmly bolted to the bed then you should both level (align, actually) and fix the lathe down to eliminate bed twist because it takes no effort at all to twist the bed if it's set on any kind of uneven floor (even floated concrete floor isn't flat).

Currently I'm refurbishing a South Bend lathe which is the old design of headstock base casting and tailstock legs, this absolutely must be levelled and fixed if it's to work as intended and keep doing so.

None of my machines are bolted down.

Instead they are mounted on antivibration machine mounts.

Boxford in their instructions for installation give effectively three ways to go.

The Centec 2A is on one of their monster cabinets and is very stable despite or because of its weight.

My Startrite pillar drill I admit is a little unstable and probably should at least have some outriggers added to the base to extend it. I haven't fixed it down as I haven't actually fixed its position in the workshop. Not danced with it, though!

As AW2, it's easier to rearrange ones workshop if needed if they are free standing but mine are lightish machines. You wouldn't want to do it with yer Colchesters and Bridgies...

The only one of my machines bolted down is my lathe,although I doubt if it needs to be.

My mill sits on a box tube frame,bolted to it,but the frame is free standing.

My drill is not bolted down but has two 56 lb cast iron weights sitting on the base table to keep it from arsing around. There are times when I need to move it away from the wall to deal with odd jobs.

Neither my spindle moulder nor my planer are bolted down

I am well aware of the danger of a drilling machine tipping over,I,ve seen it happen,not nice !,perhaps a simple strap to the rear wall ?.

What about in a location prone to earthquakes (I'm not far from Christchurch, New Zealand)? Do we bolt machines down and risk damage as they rip the rag-bolts out of the concrete, or hope the machine walks around on resilient rubber pads, but doesn't fall over? I fear the Kiwi way is to ignore the problem - "She'll be right, mate".

My WM250 V-F is on makers stand sat on a couple of rubber mats, my WM 16 is stood on 4 anti-vibration adjustable pads & both have been levelled up... according to my spirit level & digi level. I have attached both stands to the studding wall with large shelf brackets to eliminate any possibility of either toppling over as both are top heavy on supplied stands, so far so good...

​Shelf bracket can just be seen bottom right, similar fixed to lathe stand



George.

The stiffness shal be directly under the slideways of machine to be of any use

**LINK**

A canadian (Lazylathe)did a concrete slab under a Myford and tested it before and after.

https://www.homemodelenginemachinist.com/threads/concrete-counter-tops.15300/

Great improvement and he thanked me for advice.Guy had class

I then adviced him to sell the Myford and buy two Boxfords and I never heard a word of praise.

I bought a Boxford many years ago and put it directly on a piece of granite.

It works wonders.

https://imgur.com/UL2l90I

Edited By Niels Abildgaard on 06/08/2018 18:06:27

Edited By Niels Abildgaard on 06/08/2018 18:08:29

Edited By Niels Abildgaard on 06/08/2018 18:11:16