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View Full Version : To bolt or not to bolt...



Jim Phipps
05-06-2013, 9:27 PM
I'd love to hear opinions on whether or not its a good idea to bolt a full size lathe to the floor. The possible disadvantage being the tendency to spin out of balance turnings a bit faster, thereby putting more stress on bearings etc.
I'm thinking about bolting mine down but thought I'd see what y'all think about it first.

Dennis Nagle
05-06-2013, 10:43 PM
Depends on how heavy your lather is. Mine weighs 4000lbs so no need to bolt it down. Guys with light lather normally weight them down with sand bags.

Brian Finney
05-06-2013, 11:16 PM
My view is not to bolt the lathe down. The lathe vibrating/walking across the floor releases the stored energy in the system caused by the out of balance and importantly is a good safety alert that all is not well. Bolt it down and you remove that safety alert and allow the stored energy to build up without any signs - that is when things are going to fail big style without any warning.


I sometimes find that by going just a little faster or slower it reduces the vibrations - all to do with harmonics caused by the out of balance, I think.

Eric Gourieux
05-07-2013, 12:48 AM
Mine is bolted to the concrete floor. Never thought about the safety warning system of a walking lathe. I guess it is something to consider.

Fred Belknap
05-07-2013, 7:42 AM
I had two different Grizzly lathes and Grizzly recommends bolting them to a concrete floor. I think it helps with out of round blanks. I did a lot of work on both and never had any problem. I now have a Powermatic 3520 and so far it has done fine without being bolted down. You aren't going to do much turning with the lathe "walking across the floor" anyway, even if it is bolted down it will shake real bad with an out of round blank. I'm sure you will adjust the speed to smooth it out.

Faust M. Ruggiero
05-07-2013, 9:56 AM
A lathe needs to be level or there is enough flex in the frame to allow the centers to be off line. I don't mind the lathe shaking a bit but if it walks out of position the level will be disturbed.
faust

Thom Sturgill
05-07-2013, 12:02 PM
A lathe needs to be level or there is enough flex in the frame to allow the centers to be off line. I don't mind the lathe shaking a bit but if it walks out of position the level will be disturbed.
faust

Actually it needs to be TRUE, but can be out of level, but that's a quibble. And this is why industrial machines tend to be bolted, leveled and have grout packed under the feet.

Jim Sebring
05-08-2013, 12:35 AM
I've had my Nova DVR-xp bolted to the concrete floor for more than three years. It has the cast iron leg set and one hinged extension section on the ways. Since this lathe is pretty light, I also have several cases of shotgun ammo and bags of shot on the lower shelf, along with several chucks and other tools on another shelf. The machine doesn't walk anywhere and the ways stay level. I just use slow speeds when an out-of-balance piece is mounted.

Grant Wilkinson
05-08-2013, 5:20 PM
It may be worthwhile to ask the lathe maker.

I wondered about the issue that Brian raised. If the lathe is not bolted and starts to walk, it would seem that there are no stresses on the legs, and frame. If it's bolted down, all those stresses get stored in metal pieces. Could these stresses introduce fracture if they get bad enough, or if they occur often enough? I don't know the answer.

I have a Vega 2600, which is not all that heavy, but it seems to stay put most of the time. When it walks, I figure that I should slow down.

Jim Phipps
05-08-2013, 8:27 PM
It may be worthwhile to ask the lathe maker.

I had that same thought. I emailed Brent from Robust and he favors the idea of bolting. He was quick to point out, however, that rpms are no substitute for sharp tools and good technique. Bottom line, bolting to concrete adds mass and rigidity but that doesn't mean you can throw caution to the wind.

I really appreciate the replies. I'll probably bolt it down one of these days and heed your words of caution to not get too carried away with out of balance stuff just because its not walking across the floor. I really don't want to tear this lathe up (or die for that matter), but I do want to get the most out of it.

Harry Robinette
05-08-2013, 8:50 PM
I have my General 160 bolted because it has a small foot print. My Vega 2600 is not bolted and it has moved maybe a inch in the 3 years it's been in this position.