How Should I Anchor a Lathe to Concrete?

[Baxter Smith]

My shop floof is 3/4" plywood screwed to sleepers over concrete. The sleepers are spaced so that I could fit 12" wide sections of 1" foam insulation in between.
At present, my lathes feet sit directly on those sleepers at both ends.(Got lucky on the spacing) Unfortunately, they are not far enough from the wall to insert my knockout bar if I have the headstock slid to the very end. If I want to use the knockout bar, I have to move the headstock to the position shown here. (Which then means the tailstock can be too close when using a long handled bowl gouge. Complain complain!:)

246432

I would like to move the lathe 6" further away from the wall but that will place it in the middle of a span. I already get more vibration than I think I should with an out of balance blank in its present location so don't want to make it worse.

I would like the lathe to sit solidly in the position shown below.

246433

My plan at present is to draw circles on the floor around the leveling feet then move the lathe with my trailer jacks. Use a hole saw to cut through the 3/4" floor and the 1" foam. Then turn a 2 1/2"diameter end grain plug out of hard maple to place in the hole. The four leveling feet would sit on those four solid plugs.

I would also drill 1 hole through the middle of the 2"box tubing(1/4" thick) and through the floor and foam to use an anchor bolt of some type in the concrete. Would one center anchor on each end suffice, or should I go with 4(one on each corner)? I doubt there would be much flexing of that box tubing but I suppose it is possible. Any suggestions on what kinds of anchors to use? The trailer jacks can raise the lathe high enough to drop down oversomething if needed. Fastenall is only a couple miles away and I have a hammerdrill for the concrete.

Thanks for any thoughts or suggestions!

[Clint Baxter]

Definitely think you should go with an anchor at each end if you're trying to eliminate vibration. As to anchors, how thick of concrete you're going into might make a difference in what you should use. I prefer to use wedge anchors when possible, but that would then cause you to lift the unit and lower it over the anchor stud. An expansion anchor would probably work fine and then you'd be able to just run a lag bolt through your box tubing and into the anchor. Either way, you'll want to torque it down well so it doesn't move on top of your maple plugs.

Good luck with which ever way you decide.

Clint

[Jamie Donaldson]

I don't recommend anchoring a lathe to a concrete slab at all, because its almost impossible to eliminate the spring of the wooden flooring. With a large heavy lathe like your Mustard Monster, the mass of the beast should eliminate most jumping around by simply leveling the feet on a solid surface. Find a scrap piece of 1/4" steel plate if available, and if large enough to span the lathe legs on both ends that would be best. You can actually crack or torque a lathe casting by anchoring, and you will then also want to re-arrange your shop layout shortly after anchoring through the floor! Don't bother to ask me how I learned these lessons!

[Fred Belknap]

I think I would just drill some holes in the plywood and spray some foam into the 1/2" space where the lathe will set. I would leave it setting on the adjustable feet. My lathe it anchored directly to concrete floor, anchors and lag bolts. I had to use metal shims to get it level. Been that away two years. I have changed the lathe position a couple of times.

[Baxter Smith]

........ As to anchors, how thick of concrete you're going into might make a difference in what you should use. I prefer to use wedge anchors when possible, but that would then cause you to lift the unit and lower it over the anchor stud. .......

Clint
Thanks Clint. The concrete is supposed to be 4" thick in the middle. Whether it is at that spot............. Lifting and then lowering over a bolt wont be a problem since I have trailer jacks at each end to move as well as lift up and down.



I don't recommend anchoring a lathe to a concrete slab at all, because its almost impossible to eliminate the spring of the wooden flooring. With a large heavy lathe like your Mustard Monster, the mass of the beast should eliminate most jumping around by simply leveling the feet on a solid surface. Find a scrap piece of 1/4" steel plate if available, and if large enough to span the lathe legs on both ends that would be best. You can actually crack or torque a lathe casting by anchoring, and you will then also want to re-arrange your shop layout shortly after anchoring through the floor! Don't bother to ask me how I learned these lessons!

Thanks Jamie. I have some 4" x 4" 3/8" angle iron. I was about to cut to a couple pieces to a 30" length to set on the plywood at each end of the lathe. The leveling feet would then set on the steel. Just wasn't sure that would stop the plywood from flexing though I am sure it would help.
My thought was to create a solid wood connection(the plugs) between the concrete and the leveling feet on the box tubing. After leveling the ways in all directions using the leveling feet, I would then tighten the anchor bolts going through the box tubing, the plywood, the foam and into the concrete below to hold the leveling feet solidly onto the plugs. The lathe is bolted to the box tubing. My thought would be that I wouldn't place any stress on the casting during the process of tightening things down.

I have procrastinated on doing this for a couple of years because I might want to move the lathe. Hasn't happened yet...but that doesn't mean it wouldn't next week.:)

[Baxter Smith]

I think I would just drill some holes in the plywood and spray some foam into the 1/2" space where the lathe will set. I would leave it setting on the adjustable feet. My lathe it anchored directly to concrete floor, anchors and lag bolts. I had to use metal shims to get it level. Been that away two years. I have changed the lathe position a couple of times.

Thanks Fred. I cut the sleepers to 1" in thickness and there is already 1" thick foam sheets between them. If the leveling feet set directly on concrete, I assume I would be satisfied. Just can't get down there.

[kevin nee]

I think that channel iron stock would give you a flatter surface for your leveling feet than angle iron as angle usually has a slight angle to it channel would also be more ridged. My lathe is in that position all the time taking the 3520 tailstock on & off keeps you young. Good luck on which ever direction you go.

[Doug Herzberg]

Baxter, I just anchored mine with wedge anchors. For whatever reason, probably a wandering drill bit, one of the anchors was off enough for me to experience some of that torquing Jamie was talking about. Fortunately, I didn't get any of the cracking (yet). I think the anchor bolt is a soft enough steel that it gave instead of the lathe casting.

My other plan, which I have used in general construction, was to drill an oversized hole and then set bolts in hydraulic cement in the hole. This gets you some wiggle room, but in order to take advantage of it, I think you'd have to make a jig to align the bolts properly in the limited working time of the hydraulic cement.

Reading about mounting my stationary compressor in a similar fashion, I discovered that rubber isolation pads are required to allow the compressor to move. The theory is that the vibration has to go somewhere and if the compressor has to absorb it, something will eventually fail. I have noticed that large, out of balance pieces will now cause some vibration in the ways which didn't happen before when the lathe was free to scoot across the floor. It forces me to turn down the speed until the piece is more balanced, which is probably a good thing. My Grizzly is probably only about half as beefy as your mustard, so you may not even notice this problem.

Good luck and be careful. That's a lot of weight, even with trailer jacks to assist.

[Thom Sturgill]

I have procrastinated on doing this for a couple of years because I might want to move the lathe. Hasn't happened yet...but that doesn't mean it wouldn't next week.:)

And you haven't worked with the lathe where you think you want it, have you? Moving the lathe a foot might affect how other areas work for you if your shop is tight on space. Before you anchor it, take those angle irons and set them up to span the sleepers and use the lathe in that position awhile.

[Roger Chandler]

For what it is worth, I'll give you my $0.02 on this Baxter. I think Thom above has a very valid point.......especially when you consider cutting holes in the floor.........I would move the lathe to the spot on a trial basis for at least a couple of weeks, and then try perhaps a third location before I cut the floor and put those wooden plugs......

A larger piece of steel plate seems to be a good plan as well.......you could drill and tap the holes for your lathe and have other holes to match up with the sleepers and bolt it down that way without cutting into your floor. Good luck!

[Andrew Kertesz]

This may be a silly response but I don't see any shelving on the bottom of your legs. Couldn't you just build a box and fill it with sand? This should absorb vibration while adding mass to the assembly.

[John Keeton]

There is no way I would anchor my lathe to the floor - for all the reasons stated and more. I agree on making sure where you want it, and then I would invest in another 4x8 sheet of 3/4" plywood to screw to the existing sleepers, on which I would situate the lathe. That should give you the stiffness needed, and the extra width of the plywood should give you plenty of standing room so as to not affect the height of the lathe vs. your stance. Then, as Andrew suggested, I would build the box and get some sand - it makes all the difference in the world in the smoothness and quietness of the lathe. However, it is probably the weight of the lathe on the 3/4" plywood that is causing some of the "give", and I would not add the weight of the sand without beefing up the floor.

[Jerry Marcantel]

Baxter, from what I understood is, you can't get your knockout rod into the spindle very easily. If you have enough wall thickness, and the wall adjoins another something like a garage, hvac or water heater closet, punch a large enough hole( 12" x 12"?) in your wall aligning with the outboard end of you spindle. When you need to use your knockout bar, put it in the hole you punched, then into the spindle to remove whatever you're wanting to knock out. That way, you don't have to move your lathe. Of course, you'll need to dress up the hole to make it look good. .. ....... Jerry (in Tucson)

[Faust M. Ruggiero]

Bax,
Remove the plywood where the lathe will be and fill between the joists with concrete. You may have to close the gap between joists but that is no big deal. I would leave room to replace the ply on top of the newly poured concrete. I believe that will solve your problem without fastening the machine to the floor. Mine is not bolted or ballasted. I turn some funky blanks without the machine trying to walk away. However, if I did have a problem I would ballast before anchoring. If I owned a welded lathe like Oneway, I would bolt it. Cast iron is too brittle to bolt to the floor.
faust

[Olaf Vogel]

I have a similar situation. But 8" joists under the plywood. I used a hole saw to cut 1' holes for each leg. Drilled into the concrete pad underneath, screwed in 1" threaded rod, and the filled the hole with concrete. Nothing moves now.

[Baxter Smith]

I think that channel iron stock would give you a flatter surface for your leveling feet than angle iron as angle usually has a slight angle to it channel would also be more ridged. ..........QUOTE]
Thanks Kevin. The channel iron is probably a better choice but I already had the angle. I was just to lazy to cut it to see if it would help.:)

[QUOTE=Doug Herzberg;2010707].........Good luck and be careful. That's a lot of weight, even with trailer jacks to assist.
Thanks Doug. The 3 trailer jacks can be tippy but as long as I don't have to raise it more than a couple inches I should be ok moving it around.
246469246470

.... Moving the lathe a foot might affect how other areas work for you if your shop is tight on space. Before you anchor it, take those angle irons and set them up to span the sleepers and use the lathe in that position awhile.
Thanks Tom. Itshould be ok with the surrounding machines. The problem with the angle is that they wont span the sleepers running front to back and I hate to go end to end.


For what it is worth, I'll give you my $0.02 on this Baxter...........!
Thanks for your $0.02 Roger. Its more than mine.:)

Andrew, the ballast box idea is a good one. I built one to use on the A I had in this spot and it helped. But it was over the sleepers. Before I add that to this one, I think I need to solve the flex issue in the floor underneath it.


There is no way I would anchor my lathe to the floor - for all the reasons stated and more. ........ However, it is probably the weight of the lathe on the 3/4" plywood that is causing some of the "give", and I would not add the weight of the sand without beefing up the floor.
Thanks John. All those reasons are exactly why I haven't done anything more than think about it for a couple of years. Just doing it out loud now.:) I believe you are right about needing to solve the flex in the floor as a prerequisite to anything else. The solid wood plugs seemed like an easier solution and potentially more solid than adding a sheet of plywood. They would also eliminate having to deal with a lip all the way around.

Baxter, from what I understood is, you can't get your knockout rod into the spindle very easily. If you have enough wall thickness, and the wall adjoins another something like a garage, hvac or water heater closet, punch a large enough hole( 12" x 12"?) in your wall aligning with the outboard end of you spindle. When you need to use your knockout bar, put it in the hole you punched, then into the spindle to remove whatever you're wanting to knock out. That way, you don't have to move your lathe. Of course, you'll need to dress up the hole to make it look good. .. ....... Jerry (in Tucson)
Thanks Jerry but the wall is an exterior one and the north winds get a little chilly.:) I have considered a two piece knockout bar. After use, knock the extra piece back from the tailstock side.


Thanks again for all the input. My original thought was how to make the spots where the leveling feet sit more solid. Anchoring it was an alternative to the ballast box once I had the first part done. Shoveling up shavings is a little easier with it open.:)

[Jamie Donaldson]

For anyone considering the addition of a ballast box to your lathe, use washed river gravel rather than sand. It is usually available from a landscraping supplier, and won't be a potential hazard to mechanicals or electronics like sand when it escapes the box, and it will! Its also much easier to handle and clean up when necessary, such as moving the lathe to a new location.

[Reed Gray]

Well, I have never anchored a lathe to the floor, but then, they have all been on a concrete slab. I did have my old PM on 2 X 4s and screwed them to a wall to keep the lathe from walking. If you are having floor flexing problems, then the floor can be shored/braced up. Add an extra joist or two, and you can add extra cross beams under them as well, and those cross beams can have extra vertical posts under them. Should be more than enough. I am in the school of not wanting to bolt a lathe solidly to the floor. Setting anchor bolts in concrete to exactly match the mounting holes for your lathe would be difficult, and require a full sized template for placement. If you want to drill holes and insert bolts, Redheads are a brand of wedged bolt that you pound in, and then when tightened, a wedge locks into place. Excellent for minor weight bearing walls. I would worry that over time, and millions of revolutions, they could work themselves loose. If you want to drill holes, use a larger roto hammer and a real concrete bit, not one of the masonry bits from the big box store. They are fine for cinder block, and okay for brick, but first rock they hit in concrete, they dull up beyond use. You might get one 4 inch deep hole with one.

robo hippy

[Fred Belknap]

Grizzly recommended that their lathe be anchored to a concrete floor. I never realized there was an issue.

[Leo Van Der Loo]

Baxter eliminate the flex you are getting, bad for your lathe if anything besides the problem with turning larger off balance pieces.
Bigger machinery is always bolted down, the holes are cast in there for a reason, a machine can damage itself by moving around, not because it is solidly bolted to a good base like a concrete floor or a steel ship for instance (and you better have it bolted down onto the ship :eek: ).
Set the lathe where you want it and drill holes through the openings of the lathe through the floor.
Move the lathe and drill the holes to the size required for the anchors you will use (I like to use drop in anchors, as you are able to remove the bolts later and have nothing sticking up out of the floor and can then later be used again if the move was temporary) (make sure you drill as deep as possible for best structural strength, so the concrete doesn't break out)
Cut short pieces of steel pipe that are exactly ong enough to bride the gap from concrete floor to top of the wooden floor you are standing on.
Cut openings in the floor for the pipes to sit in where your holes are, set the pipes in them.
Install the drop-in anchors and screw thread ends or bolts into the anchors.
Pour concrete or masonry mix into the pipes, level with your floor and you are all set to bold your lathe down, end of most all vibration, I have had my concrete floor flex, there is always a limit to what you can do with what you have.
Of course there is always more than one way to skin a cat as they say :)

[Baxter Smith]

I have a similar situation. But 8" joists under the plywood. I used a hole saw to cut 1' holes for each leg. Drilled into the concrete pad underneath, screwed in 1" threaded rod, and the filled the hole with concrete. Nothing moves now.
Thanks Olaf. I would imagine that worked very well!


Well, I have never anchored a lathe to the floor, but then, they have all been on a concrete slab. I did have my old PM on 2 X 4s and screwed them to a wall to keep the lathe from walking. If you are having floor flexing problems, then the floor can be shored/braced up. Add an extra joist or two, and you can add extra cross beams under them as well, and those cross beams can have extra vertical posts under them. Should be more than enough. I am in the school of not wanting to bolt a lathe solidly to the floor. Setting anchor bolts in concrete to exactly match the mounting holes for your lathe would be difficult, and require a full sized template for placement. If you want to drill holes and insert bolts, Redheads are a brand of wedged bolt that you pound in, and then when tightened, a wedge locks into place. Excellent for minor weight bearing walls. I would worry that over time, and millions of revolutions, they could work themselves loose. If you want to drill holes, use a larger roto hammer and a real concrete bit, not one of the masonry bits from the big box store. They are fine for cinder block, and okay for brick, but first rock they hit in concrete, they dull up beyond use. You might get one 4 inch deep hole with one.

robo hippy
Thanks Reed, I figured you would know the ins and outs of concrete!:)


Baxter eliminate the flex you are getting, bad for your lathe if anything besides the problem with turning larger off balance pieces.
Bigger machinery is always bolted down, the holes are cast in there for a reason, a machine can damage itself by moving around, not because it is solidly bolted to a good base like a concrete floor or a steel ship for instance (and you better have it bolted down onto the ship :eek: ).
Set the lathe where you want it and drill holes through the openings of the lathe through the floor.
Move the lathe and drill the holes to the size required for the anchors you will use (I like to use drop in anchors, as you are able to remove the bolts later and have nothing sticking up out of the floor and can then later be used again if the move was temporary) (make sure you drill as deep as possible for best structural strength, so the concrete doesn't break out)
Cut short pieces of steel pipe that are exactly ong enough to bride the gap from concrete floor to top of the wooden floor you are standing on.
Cut openings in the floor for the pipes to sit in where your holes are, set the pipes in them.
Install the drop-in anchors and screw thread ends or bolts into the anchors.
Pour concrete or masonry mix into the pipes, level with your floor and you are all set to bold your lathe down, end of most all vibration, I have had my concrete floor flex, there is always a limit to what you can do with what you have.
Of course there is always more than one way to skin a cat as they say :)

Good to hear from you again Leo! Hope your move has gone well and you are back to turning on your true monster!:D

After taking everyones advice into account , I started with what seemed like the cheapest and minimalist first step this morning.

Placed the lathe where I thought I wanted it and drew circles around the leveling feet. Moved the lathe and then drilled out a slightly large hole.
246506
I had forgotten I had used 1 1/2" deep sleepers and foam rather than 1". The forgetting part is not surprising!

Turned some plugs out of rock maple to fit each hole to the proper depth.
246507246508246509

Moved the lathe back and set it down on the plugs.
246510246511

Leveled the ways then placed an out of balance blank between centers. While turning it just fast enough to vibrate a bit(about 600), I adjusted one of the feet until the vibration quieted down as much as possible. It had walked to the edge of one of the cutouts by the time I was done. Maybe double stick turners tape is a possibility on that one.;)

Drilling into the concrete, inserting an anchor bolt then pouring concrete around it as Olaf suggested, would be better but this is a definite improvement over trying to turn mid span.( Which I hadn't bothered to do more than once)

Will give this a go for a few weeks. I suppose there is a certain amount of flex in the box tubing I stuck under the legs as well. I wanted the additional height and thought a wider spacing of the feet would help. May or may not have. I had read that if you moved the headstock to the center of the ways vibration might be reduced and found it to be true. I was able to gain about 100 extra rpm before getting excessive vibration.

I will probably add the ballast box if/when I go to the next step. Even when my A was over the sleeprs, 300 extra pounds improved things.

Thanks again for all the suggestions!

[Jenny Trice]

I agree with all comments about the risks of trying to hold down the machine. A better approach is to try to dampen any vibration because if you restrict it, something is going to take the damage. I have a buddy with a Oneway 2436 and he has it on concrete leveled on top of hockey pucks. The viscoelastic pucks make a perfect vibration damper, better than your maple plugs. It stays put nicely and he does deep hollow forms on it with some pretty big chunks of wood. Before putting the pucks down, it was free standing on concrete and no matter how hard he tried to get the feet level, it walked with an out of balance load. The only way to get feet all touching at once is really to have just three points of contact, not four. If hockey pucks would provide enough elevation, that may be a good solutions for you too. Good luck.

[Reed Gray]

Leo,
Good to see that you are back. I was wondering what became of you.

robo hippy

[John Lifer]

I'd not solidly anchor the lathe to the floor unless you just can't get out movement any other way. I think your next thing to do is what a previous poster noted, add a second layer of plywood. Move the lathe, glue and screw a sheet or two down perpendicular to the way the floor is currently down. only one layer of ply is not nearly enough to dampen movement. I expect you have some bounce just walking across the floor. Level up lathe and then add lower shelf to add more weight. I'd almost guarantee you would see no movement. if you do, then only choice is to bolt down.

[Baxter Smith]

..... has it on concrete leveled on top of hockey pucks. The viscoelastic pucks make a perfect vibration damper, better than your maple plugs.....
Thanks Jenny. I read about using hockey pucks for pads somewhere. Probably on AAW. I went with the maple since I wanted direct contact with the concrete to try and eliminate any type of flexing.

My holes are 2 1/2" wide by 2 1/4" deep. A standard puck is 1" x 3". I don't know how well you could turn one down, though I could use a 3" hole saw to enlarge the hole. It would take a stack of two. Would be interesting to try!

Thanks again for all the suggestions!

[Dan Hintz]

My holes are 2 1/2" wide by 2 1/4" deep. A standard puck is 1" x 3". I don't know how well you could turn one down, though I could use a 3" hole saw to enlarge the hole. It would take a stack of two.

Use your hole saw to cut the pucks down to size, and you only need one in the hole... no need to raise the level of the puck up above the floor, just put the adjusting legs right on the puck.

[Leo Van Der Loo]

Thanks Baxter :), yes the move went well, though it took much longer than anticipated, first it took longer to sell our house in London and the setting things up here also took longer as we did all the moving ourselves, every two way trip is 3500KM (well over 2000 Miles).

Live also did get in the way of progress, between attending a wedding on the East Coast, plus vacation with the whole family a couple of weeks in Algonquin park and a 4 week trip to the Netherlands, etc., I am now able to turn and have done a few small pieces plus some birdhouses for a local art store.

Seems like being retired I'm still always busy with all kinds of things, maybe I should make a separate post about my move, however I doubt many would be interested

[Baxter Smith]

Use your hole saw to cut the pucks down to size, and you only need one in the hole... no need to raise the level of the puck up above the floor, just put the adjusting legs right on the puck.

Good thought Dan. I just wonder how well that stuff would cut with a hole saw. Probably no worse than it would turn with a scraper. The only drawback I can see is having to extend those leveling feet out down even more. I would think that the further those bolts stick out of the legs, the more prone to vibration it would be.



..........Seems like being retired I'm still always busy with all kinds of things, maybe I should make a separate post about my move, however I doubt many would be interested
I know at least one who would be.........and we all like pictures!:D

[Leo Van Der Loo]

Reed, I'm still around and kicking, but just like everything, it usually takes LOOOOnger than one thinks it will, and it did with our move.

Sold the place in London and bought another in Atikokan Ontario, a good 1000 miles North and West, more west than North :eek: ;)

Long story short, my son and his family moved up here, DIL is a family doctor here, and with 5 grand kiddies we wanted to be closer, and we probably will need some help when, .............. if we are getting even older, in the meantime I'll do some turning to keep me busy :)