Securing the lathe to the floor

The subject has been debated at length, the debates are in the archives. Basically, if you don't overload the lathe, bolting or not bolting makes no difference to your bearings. If you use bolting as an excuse to turn things that are out-of-balance at much greater speeds than you otherwise might, you could be doing harm - but you don't need to avoid bolts to avoid the harm, so if you'd like to bolt it down, do so.

Would seem to be the equivalent of broadening the footprint (infinitely). I never could figure out why it would make a difference unless there's some way the retransfer was resonant with original whacks, reinforcing them. Seems unlikely based on what I've seen. If you're a mass equates to stability type, this would seem the equivalent of adding a mass equal to mother earth.

Maybe Leo could weigh in on why an inelastic collision would be more dangerous to the bearings than an elastic one. I'm still trying to figure out why increased mass on a narrow footprint would promote greater stability than the same mass on a wider one.

Ron I have my 15" Craftsman bolted to the floor because it was easier than building a really heavy bench. My bowl lathe is bolted down because it was easier than building a dedicated bench with stability for something, the work, leaning out into the void. My mini lathe sits on a Workmate clone and my lighter spindle lathe is bolted to a bench that is not bolted to the floor. Whatever works seems to work well.

Thanks all - I appreciate the insights.

Ron

I have a General26020 and it is bolted to the floor. Even though the thing weighs almost 600lbs it is possible for it to move on the concrete floor. I can move it myself but I wouldn't say it isn't real easy. Our turning club meets at a school which has older 12" General 260s and they are all bolted to the floor. What you do want to do is make sure the floor is flat and if it isn't flat put shims under the metal pedestals near the bolt holes. Even though the General's bed is relatively massive it is possible to twist cast-iron over time. Billh

"George" wrote: (clip) Maybe Leo could weigh in on why an inelastic collision would be more dangerous to the bearings than an elastic one.(clip) ^^^^^^^^^^^^^^ I think Ecnerwal stated it correctly. Your lathe has to be able to stay where you put it. If the lathe isn't walking across the room, adding bolts won't make it walk any less, and the bearings won't know the difference. If the lathe moves around, and you solve the problem by bolting to the floor, you are subjecting the bearings to some inertial loads. This is not GOOD for the bearings, but it may not be BAD, either. Depends on whether you overdo it, and I don't know how to tell when that point is reached.

======================= Unless, of course, It's so unbalanced it pulls your foundation out of the ground !! :-)

Ken Moon Webberville, TX

===>I solved this problem long ago on this group! Do a search of the archives for magnets and there you will find ample discussion on this topic! Unfortunately my concepts were given the cold shoulder by "some" members of this group. I suspect they are all in league with the anti-LDD scoffers!

Leif

David Ellsworth has always stressed the importance of NOT attaching the lathe to the floor. His reason was because the "ways" could be bent. I don't attach my Stubby to the floor but place U-shaped wood brackets around the legs that are attached to the floor that will allow the lathe to flex its muscles without changing position. This will assure that my lathe remains perfectly level. My Stubby is very heavy but when turning very large heavy pieces (especially when hogging out vast amounts of wood when rough turning) and along with my leaning against the lathe can cause some slight movement. If you have a level floor no problem but my shop is my garage and it isn't necessarily level.....Ralph

(infinitely).

Hi Ralph

If the lathe is made from cast iron, I would not be afraid of it getting bend, if from steel and bend past its flexibility than you would have it bend. Cast iron does flex very little, it will break if pushed beyond that. Now turning a heavy out of balance piece of wood on a cast iron lathe that is not bolted down could end up breaking just because it is not bolted down, you ever seen the movie where they show the bridge that is twisting itself apart, the resonance between the headstock and the tailstock could just do that to a lathe in an extreme situation IMO.

Have fun and take care Leo Van Der Loo

Ralph J. Ramirez wrote:

"Leo Van Der Loo" wrote: (clip) you ever seen the movie where they show the bridge that is twisting itself apart, the resonance between the headstock and the tailstock could just do that to a lathe in an extreme situation IMO. ^^^^^^^^^^^^ As one Leo to another--that was news footage of the Tacoma Narrows bridge. One difference is: if that had been a lathe, they would have turned it off. Can't do that with the wind.

I wasn't sure if this was bad or not, or even if it mattered with something as small as a Jet mini, but I bolted mine to a plywood base that is bolted to the table with a rubber mat "sandwiched" in between.. It really dampens vibration and keeps the lathe from walking around the table with rough stick..

mac

Please remove splinters before emailing

Thanks for the info Leo. I was only passing on the opinion of David Ellsworth. As far as vibration of the lathe that is easy to correct, reduce the speed until the vibration subsides. I have never turned a piece that required bolting the lathe to the floor. It is possible that you are turning pieces that exceed the designed capability of the lathe. With variable speed you should be able to turn at a speed that has little to no vibration. I would never turn at a speed that could potentially cause great damage to the lathe, the wood being turned or me.....Ralph

If the lathe doesn't sit flat on the concrete when you bolt it, then you might bend something. Otherwise, should be no problem.

This may sound like sacrilege, but... A while back, I put my Rockwell Heavey Duty Lathe (600lbs.) on a couple of furniture dollies to move it across the shop. It sat on the dollies for a while as I tried to figure exactly where I wanted it. I needed to rough out a bowl blank from some walnut for a friend. I thought, what the hell, give it a try. That was three years ago. I have left it on the dolly to this day. It doesn't move or vibrate. It also raised the lathe to a better height for me as I am over 6'. Everything I have read contradicts this working, but I am now actually afraid to change it because it works so well. It is likey not useable advice, but it oddly worked for me.

Dan

N. AZ

of furniture dollies to move it across the

where I wanted it. I needed to rough out a bowl

try. That was three years ago. I have left

the lathe to a better height for me as I am

actually afraid to change it because it works so

Contradicts nothing. If asymmetrical energy of the piece does not exceed the counter of the combined footprint and mass, it shouldn't wobble.

===>IAW, if it works why change it!*G*

Leif