Discussion on all milling machines vertical & horizontal, including but not limited to Bridgeports, Hardinge, South Bend, Clausing, Van Norman, including imports.
I got a new G0755 mill delivered today, and with some effort into my garage.
As suggested in the title, is bolting it to the concrete floor a worthwhile endeavor?
If so, are the "drop in" anchors good enough? Those are the ones you drop in a drilled hole, smack with a punch tool and then you have female threads to bolt to. I am somewhat limited in that the mounting holes sit back in from the outer edge of the base, and are only tall enough to pass a 2-1/2" long bolt into the mounting hole. There is approximately 7/8" of cast iron the bolt will pass through before it is even with the concrete surface.
I am interested in the experiences y'all have had. My choice of machine was somewhat dictated by finances and logistics, I just don't think I could manage to install a 2,000 pound machine here, regardless of how much better it would be.
First, do not be in a rush to bolt it down, wait until you have it where you really want it.
Anchor bolts should go at least 3-4" into the concrete otherwise they may pull out and leave a nasty blister in the floor. From your numbers, it sounds like you can only get 1 1/2" into the concrete, not far enough.
Can you slide the machine to the side, drill the anchors in properly, then slide the machine back?
Slightly less sightly, but install the bolts with clips just outside the base.
There are different anchors but you don't want one that expands close to the surface. This may be a temporary mounting but things happen which could tip it. Anchoring is good at least on two sides. Some are better than others and that depends on your pad or concrete/cement. Look at it this way; If you have at least two really deep mounting points, they are always in reserve if you move the mill and want something else there. Bolts are cheap so get any length necessary. Just be sure that the pad wasn't lain over an electric feed or some pipeings at that point.
Well, a timely and thought provoking answer. Thank you, this helps more than you know.
Yes, 1-1/2 inches is all the more I can get into the concrete using a lag screw or bolt. And no, I don't want the blisters... I have seen them before.
One of the things I was trying to avoid was undoing the rigging, setting up the machine and then later having to re-rig it to move it. However, I never thought about using clips. Making and using those would allow me to do the drilling with the machine in place and to also install longer anchors. The mounting holes are already threaded, although I didn't measure the diameter and pitch yet, I just determined that a 3/8" bolt maximum 2-1/2" long could be placed through them.
So if I make the clips properly, I can bolt them to the base and bolt the clip to the floor. These mounting spots are along the sides where you wouldn't normally step anyway, due to the mill table projecting outwards.
BTW, the mill is already within a foot or so of its intended location, I was thinking I would have to move it further back, drill the holes and install the anchors, then move it to the anchors, so I left it where it was pending a decision.
Just a personal opinion, but having owned and run a mill for a few years now, I don't see any point in bolting it down. And if I had, I know I would have regretted it as my shop morphs over the years. It moved around quite a bit in the old shop, particularly when the 17x60 lathe took up residence beside it. Then to the new shop, and it's move by 12" or more 3 different times in less than 5 years. I've had some pretty heavy and awkward loads somewhat offset on the table, and it's never been an issue. I guess you could argue "it's not an issue, until it is, then it's too late", but the vast majority of the time the parts weigh less than the vise, so not much of an issue it seems. For a business where rather heavy loads could be a fact of life, where liability and thoughtless employees might be an issue, bolting down would be something to consider. But for a home shop, I would be more inclined to look for isolating feet and maybe an elevated base to both widen the footprint and provide convenient fork (or pallet jack) access.
I'm with Russ, from my experience there's no real need. And at most I'd do what he's already mentioned. Something to widen the foot print a bit can give you some piece of mind. It wouldn't be impossible to have a heavy vise, part, and maybe a dividing head or rotary table bolted down. Run the mills table over to the side to fit something else on the table, and you could go past the balance point where the mill could get pulled over. Even bolting it down to a couple layers of 3/4" ply 8"-10" larger all around than your mills base would be more than enough.
Looks like your's is in a garage. A Bridgeport sized mill would take up very little space more than your mill does now. My baby Bridgeport clone is in a spare bedroom.
Thanks for the additional opinions. It is definitely not going to get bolted down before I get it cleaned and set up. And I am strongly considering using some form of clip, as Russ suggested, when I do. Besides, making the clips is exactly what machinists seem to do the most, make parts for their machines to make their machines better suited for making more parts.
I know what I am missing with this mill from other options: Power down-feed, nod, a knee, variable speed (1 ph. 220V motor), no DRO (yet). And stability from another 1/2 ton of weight. I don't have the resources or the level of finances to throw at that last issue. Before I moved here, I could have managed it, but I had no need then for anything mechanical I couldn't fix with a welder and measure with a ruler and cut with a band saw or grinder. There is a term for people like that: farmers.
On some other counts, this is a huge improvement over what I had. Before, the longest single cut I could manage was about 9 inches. I had no tilt, no power feed, and I had to swap tooling between a milling vise and a compound every time I needed to change from milling to turning or back.
There's no such thing as a fully optioned out shop. Even Bill Gates couldn't ever build one. There's always something that comes along where your going to either pass or buy more tooling or machines. So we all make do with what we have. Your mill is far better than the tiny one I started with. As far as making a machine more rigid? There's some excellent information if you do a lot of digging over on the CNC Zone website that may or may not interest you. A lot of people casting epoxy / granite mixes into the hollow portions of there machine tools iron castings.
But it's also pretty easy to make good improvements in any of our machines with a bit of thought. Truing the column to the table, and then the spindle to the column would be a good first step. There's LOT'S of threads and websites around about how to do it for your mill. And I've got a lot of books that were written with the HSM in mind. They show some pretty amazing builds all done with a lathe and a milling attachment. At the time only the very well off could even think about having a proper mill in there home shop. When I wish I had bigger, better machines , those books and magazines make me a lot more thankful for what I do have.
I've said this before and it has met with some disapproval, but my friend who was a facilities manager at one of the Kennemetal shops frequently epoxied studded plates to the concrete floor and then anchored the machines to the plates. I did it with my lathe and it seems to work OK. At least the lathe is secure.
He said that merely heating the plate and smacking it with a hammer would dislodge the plate and leave no hole for anyone to trip over. The disapproval arose concerning the heating of the plate on the concrete, with the objection being that steam might be generated and the plate come loose explosively. My friend did not experience this in his tenure, but the possibility exists. In my case, the lathe can be lowered onto casters and moved to a different location.
My small horizontal mill is bolted to a frame that has suspended casters so that it can be relocated. The frame sits on shimmed blocking and the mill weighs enough so that it has never moved in use.
--earlgo
Before you do anything, you must do something else first. - Washington's principle.
pete wrote:...My baby Bridgeport clone is in a spare bedroom.
Lol. Adjacent to my garage is an 8x12 or so room, which I walk through to enter the garage, with a laundry room at the far end. It would be relatively easy to partition this entire area off from the rest of the house, remove the carpeting and expand my shop. Domestic bliss is the main obstacle keeping this from happening.
for my book I would go with the drop in anchors shown in the attachment above. the first advantage is you can unscrew the anchor rod and are left with a flush surface. the hole can be sealed with a bit of silicone. threaded rod will let them be set deep.
lag bolts will loosen and fail when you need them most.
I have the same mill. The manual states that it can be done either way, bolted down or on feet. I chose the screwed in leveling machine, anti-vibration feet/pads. Works for me.
