Bolting a 12x36 to the floor

[calstar]

This is my first lathe, it came mounted on a very beefy Logan 2 cabinet/tray mount. Question is does it have to be bolted to the floor? I can do it but just wondering if I would lose much accuracy if not bolted down, cabinet standing on the concrete on leveling screws(1" dia). I do have a machinist level available to level out the lathe bed. The lathe seems to be pretty tight, I would probably get more accuracy if its bolted down but how much would I lose if freestanding? Lots of variables at play I know, just trying to learn as I go.

thanks, Brian

 

[pdentrem]

None of our lathes at work are bolted down, but they are heavier than an Atlas by 3X and more. My Atlas was mounted on a stiff table and leveled, that was it. My current lathe is not bolted either. What is more important is being straight from headstock to tailstock. Many discussions about that.
Pierre

 

[wwunder]

My TV-36 is mounted on a welded steel stand that is not bolted to the floor... It would probably be better to be bolted down, but I neither work to extremely tight tolerances nor have issues with the finish that I am achieving so its not a priority to me.

 

[richl]

I am a noob here... so take this for what it is worth. My.13"x40" lathe is about 1300 lbs I have noticed while reconditioning it that it rocks when cranking handles. I.am going.to make a 2"x3" tube frame to anchor to and I was also planning to hammer drill some expansion.bolts to the floor. They should allow me to level it up.... in my case I think it might be the smartest move but maybe my floor is not as smooth as others.Rich

 

[Beethovin]

There is a valid reason for bolting a lathe to a solid base. Cast iron does move, this creates out of tolerance parts. Leveling and bolting securely to a solid base helps reduce unwanted variations in machine bed alignment. Less of a problem on a universal mill, major problems on horizontal boring machines and VTLs. Universal mills have their own set of built in problems RE accuracy. Knee horizontal way perpendicular to vertical column miss alignment (in two co-ordinates) has driven many fine craftsmen to distraction. Couple this with long overhanging tables and poor fitment to begin with and I can still hear the complaints more than 40 years later!
In short, bolt it down and use a precision level, take the time and effort to make sure everything is level if you want to produce anything to a useful tolerance to begin with:nuts:.

 

[Ray C]

For the machine you're talking about, bolting it to the ground is an option but, you will then need to loosen the machine's base bolts in order to shim it when you go to align the lathe. This has been discussed here by professional machine rebuilders many times. My bench is 3x4x1/2" angle iron and weighs about 350lbs and has another 3-400lbs of tooling on the lower shelf. It ain't going nowhere short of an earthquake. The legs are set on heavy neoprene pads. The bench itself has movable adjusting points where the lathe is bolted to and that allows me to align the lathe until it cuts perfectly. The bench itself has a very slight lean forward to allow fluids in the drain pan to settle where it can be conveniently wiped up. I would estimate that the front legs are 1/32" pitched to allow things to drain as I want them to. Lathes do not need to be level to work properly -they need to be aligned so they cut straight. If you search here for "2 collar method" and "Rollie Method" those posts will show you how to align the lathe. This is how professional lathes are setup. Lathe alignment needs to be checked periodically whether it's bolted to the floor or not.


Ray

 

[fastback]

I have to agree with not bolting down the lathe. I have three lathes the smallest being a 6-inch Atlas and they are not bolted. The weight of the 6 inch with base is probably in the 250 t0 300 lb range. My opinion is just make the base solid and weigh it down with tools and/or stock and you will be fine for hobby work.

 

[kd4gij]

Unless you are making parts for NASA :roflmao: I wouldn't wory about bolting it down. Mine isn't bolted down and it cuts just fine.