Milling machine in the (wood floored) workshop

[William AyerstParticipant @williamayerst55662]

My shed is a standard 8 x 16' wooden affair, but has been insulated, powered, lit and guttered with some heavy duty security. It is on a thick concrete pad, with wooden joists on 17" centres topped with planks. If you jump up and down on an area above a joist, it's very solid, but in the middle of each span there is a little movement. I need to ensure that the machines are as rigid without going bananas on it.

I have an ML7 on a welded base – (say, 120kg) whose feet sit awkwardly in the middle of the joist span. I had thought for this to spread the weight using ply or scaffold boards screwed into the floor, across the joists.

Regardless of how that turns out, however – I am hopefully going to get a milling machine (350kg) soon, the feet of which should roughly align to the joist spacing – and I can't really manage shifting around a milling machine on my own in the same way I can with the lathe, so I need to get it pretty right the first time around.

I see there to be two options – strengthen the floor, or create a new one, but I'm not sure which will be just 'good enough':

• Place a sheet of 1" plywood or 38mm scaffold planks beneath the lathe and mill, screwed into the floor and joists, and screw or bolt the machines down into that.
• Cut a hole for a pad in the floor about a 8" bigger than the machine footprint, remove the planks and joists, brace the new ends of the floorboards at the cut, shutter in and pour in concrete to bring it up to floor level.

My only concern with the latter is how permanent it is, and in general I have a few questions about how it would work, i.e.

• Do I want it to bond to the layer below?
• How do I handle damp proofing?
• Should I be thinking about drilling holes into the concrete for fixing studs? I don't know how any of that works….

How seriously should I consider doing this under the lathe also? Clearly the concrete pad method is the most desirable but I'm concerned that should I want to rearrange the workshop in future I'm going to be a little stuck and start running out of floor!

Any thoughts or opinions gladly taken.

Edited By William Ayerst on 03/07/2021 14:43:30

Edited By William Ayerst on 03/07/2021 15:11:20

[William AyerstParticipant @williamayerst55662]

[jimmy bParticipant @jimmyb]

I had a similar problem when I put my Crusader lathe in the shed.

In the end I had to cut through the floor and poor a concrete base for it.

Good luck.

Jim

[old martParticipant @oldmart]

1" plywood is extremely strong, and spread across several joists would be plenty. Get a sheet of external type, marine ply is very expensive.

[pgk pgkParticipant @pgkpgk17461]

If planning on pouring in a floor then my inclination would be to put down a damp membrane first so that if you ever decide to chisel it away it can be done. If not a thick enough joist then throw in some mesh weld perhaps?

pgk

[Peter Simpson 1Participant @petersimpson1]

In my wooden workshop ,I have 2 lathes 2 milling machines and a shaping machine. I cut out the foot print of all the machines and poured concrete through the wooden floor to the concrete pad below. Very easy to do and you end up with a good solid base for the machines to stand on.

[William AyerstParticipant @williamayerst55662]

Jimmy, I think it sounds drastic but the more I think about the the more reasonable it seems – cheaper, more stable, etc.

With regard to permanance, right now there is shelving along the short wall next to where 'mill' is shown in this diagram, but it seems like the only logical place:

I can't really put the mill opposite the bench or the lathe, as it only leaves about 2' room between them, so it has to go opposite either the drill or the grinder – and I want the grinder away from the other machine tools if possible, so even if I get rid of my bench drill at some point the grinder is likely to end up in that spot, or on a bit of wood chucked under the workbench.

I guess if I make the pad larger than the base, i.e. 3' x 3' – then I have a bit of flexibility in future, but it does peg the machine in that corner "forever"….

[not done it yetParticipant @notdoneityet]

A fairly dry screed should be sufficient – not wet concrete – and more easily removed in the future. More easily levelled, too if only a fairly thin layer.

I’m in the process of moving my 2B at the present time. Only a 180 degree turn and about a metre. The Stand will be raised by 150mm to place it at what I think is a better height for me.

Raising or lowering a 2B, while on its wide stand, is not something I would relish, even on a concrete floor.

Edited By not done it yet on 03/07/2021 16:23:15

[John HaineParticipant @johnhaine32865]

Put each machine foot on a threaded rod adjuster as big as will fit, lead these through the wood so they rest on the concrete. Have a nut underneath the foot for levelling.

[duncan webster 1Participant @duncanwebster1]

My floor is 22mm chipboard on 25mm polystyrene on 24"sq concrete flags (the original garage floor) Where I have heavy machine feet I've cut a 4" or so square hole in the floor and used solid wood packers down to the flags.

[William AyerstParticipant @williamayerst55662]

All, do you think it would make sense for the mill to face the door (orange) or into the workshop (yellow)? My expected concrete pad outline is about 3' x 3' – may be shifted inboard depending on not done it yet's answer)

Not done it yet, how tall are you? I'm 5'8"ish and found once I got my ML7 to a good height (41" to the carriage wheel, 44" to the cross slide wheel) it was a revelation – and I guess now is the time to make sure! If you have one may I ask for a bit of cheeky information i.e. the distance from a wall or the rearmost projection to the rear feet, and to the rear of the table when it's as far back as possible?

John H – are you suggesting to use something like a hole cutter through the floor to put the feet down into the pad below and keep the machine raised up onto those rods?

pgk – I guess a 3' x 3' x 4" concrete pad will be plenty stable enough without being bonded to the pad below – I was thinking exactly what you mentioned about potentially being able to be removed in future. What do you mean about mesh weld please?

Old mart – I was leaning heavily towards ply but after reflection – it's more than four times the price of concrete and would be less stable, right?

jimmy b, peter1 – thank you for your anecdotes – all in support.

 

Edited By William Ayerst on 03/07/2021 17:04:48

[William AyerstParticipant @williamayerst55662]

Duncan, that's a good point – I hadn't considered using solid wood under the feet!

[SteviegtrParticipant @steviegtr]

+1 for cutting a hole in the floor & harcore + concrete on some visquine for damp proof. The last thing you would want is the mill wobbling about.

Steve.

[Dave HalfordParticipant @davehalford22513]

I would use concrete blocks if you already have a concrete base, you can buy singles for £1.66 at B&Q

[pgk pgkParticipant @pgkpgk17461]

Posted by William Ayerst on 03/07/2021 17:02:27:

pgk – I guess a 3' x 3' x 4" concrete pad will be plenty stable enough without being bonded to the pad below – I was thinking exactly what you mentioned about potentially being able to be removed in future. What do you mean about mesh weld please?

I wasn't sure about your depth for concrete. If it was only a couple of inches then some sort of reinforcement would be ideal and it’s not a big enough area to warrant rebar. A piece of mesh-weld or even chicken-wire could be used. At 4" I wouldn't bother

pgk

[William AyerstParticipant @williamayerst55662]

Hm ok – so chicken wire pushed into the void before shoveling in dry screed – that works. It sounds like a good idea to lay out a bit of damp proof polythene or a cut up builder's sack underneath so it can be separate from the main pad?

Also, a global shortage of cement right now. Great.

[Howard LewisParticipant @howardlewis46836]

My Warco Economy Mill /Drill is bolted to an ex industry steel bench, made from angle iron.

Beneath it are drawers, (Well filled ) sliding on angle irons, so there is a lot of weight there.

It stands on a rectangular angle iron frame , intended as a load spreader, on the 3/4 inch ply floor, which stands on 8 x 2 bearers, set on 18 inch centres, on 2 inch paving slabs bedded onto a sand /cement base .

Have never been aware of any lack of rigidity in this set up.

Howard

[Ady1Participant @ady1]

Angle iron welded together into a frame is used a lot for machine tools

Steel tube up from the concrete and angle iron at the floor level?

Downside is you can never move your machine about

[Nigel McBurney 1Participant @nigelmcburney1]

Why not just thicken the whole floor,this would allow future repositioning of the machines. Suggest thicken the whole floor with four sheets of 18mm shutterring ply which is the cheapest ply and thenput down on top four sheets of a better quality 18mm ply to provide a better surface . Dont worry too much about the machines weight 350 kg is nothing in terms of machine tools and easily moved with a crowbar,at one time I had a S7 in an upstairs bedroom,16 inch pitch joist with 20mm t and g floor boards ,no problems with stability or accuracy.

[Phil PParticipant @philp]

I tried all the options of thickening the floor etc, but it still wobbled around, so I did what John Haine suggested earlier and cut some 3" diameter holes through the floor boards and made some solid steel slugs to sit just proud of the floor and sitting directly onto the concrete beneath, the tops of the steel slugs were counterbored in the centre so my machine jacking feet do not slip off. Also run a bead of sealant around the steel slug.

I have never had any more trouble.

Phil

[VicParticipant @vic]

I’ve got a VMC simply screwed down to my wooden shed floor and haven’t experienced any problems with it so far.

[not done it yetParticipant @notdoneityet]

Hi William,

I’m only 1.74m (decreasing in my old age) but I have found the z axis handwheel too low when at any lower level. I’m not yet fully decided on whether to go 150mm or 100mm, but with power feed on the x axis, it only really leaves the y a bit on the high side – but the z is really the hard work one.

At the moment the base is cocked up at the front with an approx 30mm piece of pipe under the woodwork. I might finish up lowering it a bit – but only because the drawbar is awkward to change when the riser block is in place (ceiling height).

With a lathe, the hand wheels are always at the same height but not so with a mill. I just prefer mine jacked up higher than ‘the norm’. I suspect that the original design was drafted with the view that it was easier to raise the machine on a plinth than lower the stand?

[William AyerstParticipant @williamayerst55662]

By some freak chance, the mill's perfect position in the workshop puts the feet directly over the joists in the workshop. My plan is to use two layers of 3/4" plywood to spread the weight across more of the floor, and then see how it goes. If there is movement or vibration then I will use the opportunity to strip and refurbish it, and pour some concrete or use some steel slugs.

Cheers,

[Nigel Graham 2Participant @nigelgraham2]

I solved the same problem in my previous home by cutting four recta ngular holes in the floor, cementing small brick plinths to the underlying concrete a few inches below the shed floor, and putting a thick PVC pad as damp-proof / levelling layer between the milling-machine's angle-iron bench and the bricks.

[William AyerstParticipant @williamayerst55662]

As smug as I was in my previous post it looks like I miscalculated, and the base width did not include the feet – which are 2" outboard instead of inboard of the footprint. This puts them either side of the joists, quite a few inches onto flimsy 15mm planks with just air underneath – and so the problem in the original premise remains.

I must admit I am really quite nervous about pouring another pad. I have the material and it won't be the first time I've poured concrete. But it feels like a really significant amendment to the workshop. Everyone 'in the real world' I've spoken to thinks it's a bit mad.

The alternative is to chuck a cut down 8" x 3" railway sleeper under each pair of feet. The timber will be supported by three joists, one at each end and one in the middle. The mill would be roughly central on the length of the timber. No structural changes required but clearly not the gold standard.

This is an old mill and I'm not building jet engines, and I would have thought the timbers would be sufficient – but I really don't have the benefit of experience to know what meaningful difference there would be.

Edited By William Ayerst on 06/07/2021 15:57:17

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