Concrete base for miling machine

Hi,

I'm awaiting delivery of a Warco VMC and have a problem in that the floor where it's going to go is on a slight slope. The floor is concrete and slopes from back to front a bit less than an inch in 24 inches. My first thoughts regarding this were to shim under the mill where the hold-down bolts go, but I've had second thoughts and wondered about laying a concrete "pad" somewhat bigger than the mill footprint to level the floor just where the mill will go.

Has anyone here faced a similar problem in the past ? And specifically, what are the chances that a new layer of concrete, say 3 inches thick, will bond to a 20 year old coincrete floor ?

What would you do ?

Thanks,

David

Reply to
mangled_us
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Would have thought bonding would be perfectly possible with "Uni Bond" or similar to prime the joint. However, with a 3" pad, not clear that you would care very much whether it bonded or not - it won't be going anywhere.

Regards, Tony

Reply to
Tony Jeffree

Why not use proper anti-vibration levelling pads? This is what I did to counter both the slight slope on my garage floor, and to compensate for the fact that the base of my VMC stand wasn't welded level (right side plate was welded some 4mm higher than the other 3).

Theres a picture of mine here

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and there is one of many sites for the pads here
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Peter

Reply to
Peter Neill

What a fine idea ! Thanks for that, I've never come across those before. Can you tell me what size you used, or equivalently what size the hold-down bolt holes are in the VMC cabinet ?

Thanks again,

David

Reply to
mangled_us

The bolt holes in the cabinet base are 12mm. I had some spare levelling pads from an old moulding machine at work, so I used these instead of buying new, but as these ones had a 16mm diameter stud I had to drill the cabinet holes out a bit.

The actual pad size on the ones I used are around 125mm diameter, and the rubber is around 40mm thick. The machine is very stable on these and the size is probably a bit bigger than actually needed - previously these were underneath a moulding machine weighing around 5 tonnes.

Peter

Reply to
Peter Neill

Can you tell me if you have any feeling for how much unlevel the feet will take out ? I have a 19mm fall over 600mm distance and I see from the makes spec that the rubber is only 25mm thick in the first place for the parts I need.

If anyone knows any alternative mounting feet that can cope with this amount of unlevel I'd be interested to know a UK source.

Also, from what you said you may not have needed to look, but do you happen to know a supplier who will sell small quantities from stock ?

Thanks,

David

Reply to
mangled_us

David

I'm no expert in these but if they are like the ones I used a few years ago the range to level by screwing the bolt in/out is quite limited, I seem to remember about 6mm for 3" ones. However, if one packs between the top of the foot and machine base then it is the length of the bolt that becomes the limiting factor. We regularly used 3/4" spacers here and easily took out falls quite a bit greater than you describe, there was still plenty of flex to ensure the foot sat square on the floor. Sorry can't remember who made them or where they came from but do remember they worked like a dream. Much easier than mixing all that concrete.

Regards

Keith

Reply to
jontom_1uk

As others have said, you could use anti-vibration feet. If the adjustment range is not sufficient, you could maybe cast your own (have a look at Devcon Flexane - "other casting rubbers are available") As far as I can see from the link provided, these do not fix the machine to the floor.

If you can live with the machine being fixed to the floor, just use allthread studding epoxy-resined (Hilti HIT150 - similar disclaimer) into the concrete, with a nut above and below the machine (check out the thread about mounting a Myford onto a Boxford stand - the principle is the same).

Reply to
John Montrose

David, I checked the ones I used and they are from Sunnex in the UK, web here

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, and the type is OSM2. The nominal adjustment range on my size is 13mm, but as Keith said you can use spacers providing the bolt is long enough which they usually are. Alternatively, you could use 2 OSM1 and 2 OSM2 for example,which would then give a 21mm nominal range. These things aren't usually sold in big volumes so 4-off would be a quite normal order.

Peter

Reply to
Peter Neill

Why not chemfix some 12 mm stud into the existing concrete floor and use nuts to adjust the height?

Mark

Reply to
mark.howard10

A great advantage to the vibration feet that have been mentioned is that they are not permanently fixed to the floor. I guarantee that at some point in the future you will want to re-arrange your workshop, and if you have a 3" lump of concrete it'll be a right b****r to move.

Regards

Kevin

Reply to
Kevin Steele

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