Securing lathe to cemet floor

[Rick Doganiero]

Hello,

I am interested in securing my lathe (Robust AB) to the concrete floor in my shop. Some people have recomended the self tapping screws (Tapcon) while others the lag bolt anchor type systems.

I'd like to hear from those of you out there how you secured your lathe to concrete floor.

Rick D

 

[Bill Boehme]

Hello,

I am interested in securing my lathe (Robust AB) to the concrete floor in my shop. Some people have recomended the self tapping screws (Tapcon) while others the lag bolt anchor type systems.

I'd like to hear from those of you out there how you secured your lathe to concrete floor.

Rick D

The Tapcon screws are not self tapping. You have to drill a hole. They are OK for light duty stuff, but depending on the strength of the concrete and the torque used to drive them in, they are likely to cause cracks in the slab. The only type of load where concrete is strong is compression and this is NOT a compression load.

The wedge lock type screws are a bit better, but if over torqued or subject to vibration, they will likely also lead to fractures in the slab. The lead or zinc shield types are my favorites. The metal is soft enough to conform to the screw and hole and provide adequate holdng.

 

[robo hippy]

They used to have some called Red Heads, where you drill a proper sized hole in the concrete, and then drive the bolt in, where a wedge on it pretty much locks it into place. There are others that use a ceramic epoxy. Note, make sure to use a heavy roto hammer, and don't even think about the 'masonry' bits from the big box stores. They are only good for going into cinder block. I did concrete work for 30 years.

I haven't bolted mine down, and most likely will not. No real point, except to limit how it wants to walk across the floor. With my old PM, I had some holes drilled into some 2 X 4s, and set the lathe feet into the holes, and then nailed and screwed them into the wall. Worked fine.

robo hippy

 

[Thomas Stegall]

Doesn't bolting down your lathe transfer alot of vibration unnecessarily into the bearings?

 

[Bill Boehme]

Doesn't bolting down your lathe transfer alot of vibration unnecessarily into the bearings?

I don't think that it does -- certainly not for large heavy lathes. Whether or not it is bolted down should not have much effect on acoustic vibrations (meaning anything from about 10 Hz and up) because the spindle is for all practical purposes decoupled from the feet at those frequencies. Another way of saying this is that you could do anything you wish to the feet and it isn't going to have any effect on whatever vibration exists between the spindle and headstock.

This is not saying that the bearings can't be damaged in some extreme scenario where the dynamics of an unbalanced spinning load might exceed the load ratings of a bearing. For example a very heavy out-of-balance load spinning at an inappropriately high speed sufficient to cause the lathe to waltz all over the shop probably isn't good for any part of the lathe nor the person standing next to it. Bolting it to the floor might solve the problem of chasing the lathe around the shop, but that is about it. Bolting the lathe to the floor is more like treating a symptom than the cause.

 

[dbonertz]

The red heads that Robo mentioned are the way to go. http://www.homedepot.com/h_d1/N-5yc1vZas35/h_d2/Navigation?catalogId=10053&langId=-1&storeId=10051
A friend used the lead type and others and they always pulled loose or just fell apart. I finally set his lathe with red heads about five years ago and he has had no problems since (no concrete cracking either). I have had my lathe set with red heads about five years also with no problems. If you buy the masonry bits from Home depot get the Bosch brand and it will work just fine for your application (I am a contractor and have had good luck with this brand only from the big box stores).
The friend I mentioned earlier has had his lathes bolted to the floor for 20 years and has turned well over ten thousand bowls with no issues. Disclaimer is he uses vicmarc lathes which are known to be a very high quality lathe. He still has the original bearings in his rough out lathe and his finish lathe. Bolting the lathe may add some stress but from what I have witnessed it is not enough to worry about unless you own a lathe that is not of high quality. After speaking with a friend who is a metallurgist he also does not believe it will harm the lathe. He told me if you're anal then put a 1/8" hard rubber spacer between the lathe feet and the concrete floor then bolt it down. This is what many professional shops do according to him.

Good luck,

Dale

 

[Ian Thorn]

Bolting the lathe down is a bit like having a sore back and taking pain killers then still lifting heavy things, the pain killers being the bolts the sore back being the out of ballance object spining to fix the vibration slow the speed down untill it is in ballance as it not only damages the whole lathe but your turning could go walkeys around the workshop, stay safe

 

[billooms]

I used to have my Woodfast bolted to the floor, but since moving the shop I didn't bother to bolt it again.

One thing to consider is that by bolting it firmly to the floor, you may cause some stress on the bed of the lathe. According to Roger at Craft supplies, even an unbolted lathe can have misalignment due to uneven pressure just from bolting the bed to the base. In cases of misalignment, he recommends readjusting the torque on the bolts connecting the lathe to the base as a first step in aligning the tailstock. I was surprised that even on heavy machines like a Woodfast or VicMarc that one could twist the bed, but apparently this is quite common.

So keep that in mind as you tighten bolts down to the floor.

 

[MichaelMouse]

One thing to consider is that by bolting it firmly to the floor, you may cause some stress on the bed of the lathe. According to Roger at Craft supplies, even an unbolted lathe can have misalignment due to uneven pressure just from bolting the bed to the base.

OR bolting it to a homemade top. OR putting its own stand on an uneven floor without shimming for twist. Maybe even by poorly distributed stabilizing sandbags! Of course, the weeble advocates seldom admit that they're just adding a lesser mass to their lathe than mother earth herself. They keep coming up with this "bearing stress" argument against the latter. If no energy is destroyed by moving the lathe, the load is the same with either.

I am also an advocate of using the old lead anchors direct into concrete, if you go that route.

 

[john lucas]

Bill I've found the best way to keep the bed aligned is to level the bed both along the headstock axis and perpendicular to that. I had problems with my tailstock not being aligned and it turned out that just a few turns of a couple of the feet was enough to level everything and bring the lathe back into alignment.
I have not bolted a lathe to the floor yet. I find I have to move it too often when trying to redo the shop or even just to have enough room to work on some projects. I envy the people who have all kinds of room in their shops.

 

[Patrick Miller]

I have bolted my Oneway 1640 to the concrete floor using 8 of the 3/8" Red Head type anchors, 3" long if I recall- more depth, less chance of cracks. Buy, borrow, rent or steal a quality Roto hammer and this will be a 15 minute job. I could tell a difference immediately in smoothness and stability. Not sure about affecting bearing life- this thing runs with hot bearings anyway so I guess I'm not particularly concerned. Anchors away!

 

[Ian Robertson]

They keep coming up with this "bearing stress" argument against the latter. If no energy is destroyed by moving the lathe, the load is the same with either.

I agree.

The bearings in most headstocks are made to withstand far more shock loading than any out of balance bit of wood is going to put on it.

Car rear wheel bearings in most cases are about the same size and look at the loads and shocks that they carry.

All my big lathes are bolted down and suffered no ill effects in 10 years of use. I would bolt my small ones down too except I have to move them frequently for access to the big ones.

 

[John Torchick]

I had thought about bolting the lathe to the floor but haven't yet. John Lucas make a good case for not bolting to the floor. Plus, I have a wet-weather spring under the house. During real heavy and frequent rains, you can see water bubbling up between the concrete floor of the basement and the blacktop driveway. I sure don't want an indoor pool!

 

[MichaelMouse]

Y'know, If you turn the heads of those bolts counterclockwise you can take them away altogether. Possibly a solution for moving the lathe?

 

[stu senator]

The major concern would be alignment. To secure to the floor tightly may twist the machine base and frame. Leveling is the big problem and must be done carefully.

I have mounted other machinery using vibration damping pads. These can be found at McMaster Carr on line.

http://www.mcmaster.com/#vibration-control-mats/=izlwlb

These will prevent vibration from reaching the floor but the machine will still vibrate.. You must pick a pad material based on the machine weight and foot size. Leave extra weight for big logs and any damping material weight.

Stu

 

[john lucas]

MM I could remove the bolts but then I'd still have holes in the floor. Maybe sometime in my life I'll have a shop large enough to put a machine down and leave it sit there for a while. I've moved them two or three times now and I've only been in this house 7 years. I need to move them again, hopefully this next time they will sit for a while.

 

[Mark Levitski]

I've moved them two or three times now and I've only been in this house 7 years

Although I haven't moved tool positions much yet, this is why I haven't resorted to bolting to the concrete (I figure I'll be doing some rearranging eventually). You could try construction adhesive and wood to lag bolt into instead of drilling into concrete. Not sure if you do have to move machins around that separating the adhesive would be better than leaving a few holes to fill in, but this is what I did where my electrical conduit drops down to the boxes on the floor. There are quite a few and I didn't want to screw them all to the floor.

 

[odie]

My Woodfast has been bolted to the floor since I purchased it in 1992. (One move from my old shop to the new one in 1997, when I purchased this home.)

The Northwood lathe was also bolted to the floor back in the 1980's.

In all cases, I've used the cast anchors with lag bolts. These have never lost their grip for me......but, I seldom use severely out of balance wood, so that might be a consideration. I've used the Red Head anchors at work for machinery there. These also seem to work well.

With regard to the "to anchor, or not to anchor" question......back in the 1980's, it seems to me that the prevailing thinking at that time, was to anchor the lathe to provide more resistance to lathe vibration. These days, there is more controversy over the issue, whenever the subject comes up. (This may be the product of more opinions gaining access to the flow of information, due to the Internet. Might be a good thing, and might not be......mainly because it's hard to find a subject, ANY subject, where what used to be common thought, isn't now in doubt!)

Anchoring is such an easy thing to do, that I don't believe I'll go without it.

ooc

 

[KellyDunn]

I wanted my oneway spindle chest high. But the same thing would work close to the floor. I drilled holes and cleand them out good. Used the two part epoxy the building guys are using to achor bolts. I put in 1/2 inch all thread. I put a nut with a washer on the all thread. Oh, I had the lathe above the holes using some 4 bys so I did not have to try and lift the sucker over the bolts. When the epoxy cured I lowered the lathe onto the washers. It took a bit of tweeking the nuts to get it what seemed perfect so I did not put any twist of any kind. If worried about vibration also use some rubber for heavy machines above the washer. When happy its aligned put your top washers and bolts on and bingo. For me I cast concrete up to the bottom of the lathe feet. Out of round pieces will still make the lathe sway. But its from the top of the feet up.
I had another lathe bolted to the concrete. There was an anchor that you hammered into a drilled hole. When your bolt was put in the sucker never moved. When I sold that lathe those anchors would not come out of the concrete. The lead ones are trash. Came loose in no time. With epoxy and all thread if you had to move the lathe you could just saw the bolt flush with the floor.

 

[Dale Miner]

Kelly,

The trick to the wedge type bolts that you drive in is to drill the hole extra deep during installation. When the need for the bolts has passed, the part that is above the floor can be driven in flush to eliminate the tripping hazard.

I like the wedge type myself, if the concrete is thick enough. A 4" floor is minumum, and at 4", the epoxy in type are probably better.

 

[odie]

Just a thought.......

One can judge whether this applies to any meaningful degree, but isn't it true that if one does anchor his lathe, any vibration transmitted will depend on the structural integrity of the lathe itself.....?

......Whereas, a lathe that is held in place by gravity, will transmit vibration according to the "match" of his lathe to the supporting floor surface. Those who choose to support their lathe on a rubber surface, will have vibration dependent on the give-and-take abilities of the rubber used.

Anyway, it just seems more likely to me, in a theoretical sense, that the more stable, and less option for movement, the less resulting vibration there will be. As long as there is room for movement differential between everything upstream of the spindle bearings, and downstream of the spindle bearings, there will ultimately be a measurable vibration between the cutting edge of your tool, and the workpiece.

(I think! )

ooc

 

[Owen Lowe]

With epoxy and all thread if you had to move the lathe you could just saw the bolt flush with the floor.

If you apply heat (propane torch) you can soften the epoxy and pull the all-thread out with no cutting. Then fill the hole with mortar or other patch.

 

[MichaelMouse]

Just a thought.......

One can judge whether this applies to any meaningful degree, but isn't it true that if one does anchor his lathe, any vibration transmitted will depend on the structural integrity of the lathe itself.....?

I assume by the rest of your post that you are not speaking of vibration, but oscillation.

Does not apply. If there is no movement of the lathe caused by impact or unbalanced work, makes not a bit of difference to the bearings what prevented it. If the lathe moves - does a bit of "work" overcoming inertia, there will be a bit less third law stress due to momentum transfer. But there will be a contra coup, where the lathe hits back. Might actually be worse for any bearing gap than the single event with the immoveable mass.

All the anchoring practices are really unnecessary if the footprint of the lathe is properly done. Nice rigid splayed legs don't need weebling.

 

[JOHN KARTCHNER]

An Alternative to Bolting to the Floor

I wanted mobility along with rigidity so I mounted my PM 4224 to 4"X6" fir beams which protrude 3" past the splayed cast iron legs. I then mounted heavy-duty 3" swivel casters on the fir timbers. I then epoxied 1" X 8tpi rod connectors in 1 3/4" holes drilled toward the end of the beams making certain that they were in line with the legs. I then used 1" 8tpi set screws to raise the lathe off the casters. Each set screw seats in a 1" forstner induced depression in a hockey puck. Using two levels I adjusted each set screw until the lathe bed was leveled side-to-side and end-to-end. I have had no problem with "walking" lathes.

I helped a friend use this same system on his large Vicmark. Rather than beams he used 2" X 6" ash. His rod connectors reach all the way through the plank, so he adjusts the set screws from above (which is much easier). He has never had any trouble with his lathe having wanderlust. Neither lathe has moved even 1/4" from where we originally placed them unless we wanted to move them on the casters.

 

[john lucas]

I had a friend who put 3" angle iron under his 3520. This stuff was about 3/8" thick and 5 feet long. On the headstock side he left it centered on the lathe. On the tailstock end he mounted it so one end was flush with the leg and stuck out the back. That way he didn't trip over it when moving to the tailstock end. John was turning lots of offcenter work and it was amazing how stabil it made the lathe.

 

[Frederick Williamson]

Bolting down lathe

I agree with Walter Ambrosch. Bolting solid to a floor transmits a lot of vibration and is rough on bearings. A hard rubber cushion, and then lightly bolted so the lathe won't wander would be better, and then of course lots of extra mass underneath. A wider stance helps even more, say bolting on a doubled 3/4" plywood triangle to both ends and having the center relieved so the outside "feet" are the active parts. Fred

 

[musky]

As a proud owner of a Robust AB, and past owner of a Oneway 2436, I can not see any need to have to bolt a Robust AB to the floor. While I used to get some vibration at times on the Oneway, I have only a slight trace of vibration with my Robust, and that would be with very large and considerably out of balance wood. A quarter of a turn on one of the foot leveling screws can make a huge differance. You might want to try leveling again, by mounting a big out of balance piece of wood, and turning one leg only, up a quarter, then half a turn, then down a quarter and half a turn, from where you started. It should level somewhere within that range. You may have to adjust further, but you should have a good idea of what way to go at this point. If your lathe has been leveled correctly, your tailstock and head stock should line up.

 

[Bill Boehme]

As a proud owner of a Robust AB, and past owner of a Oneway 2436, I can not see any need to have to bolt a Robust AB to the floor. While I used to get some vibration at times on the Oneway, I have only a slight trace of vibration with my Robust, and that would be with very large and considerably out of balance wood. A quarter of a turn on one of the foot leveling screws can make a huge differance. You might want to try leveling again, by mounting a big out of balance piece of wood, and turning one leg only, up a quarter, then half a turn, then down a quarter and half a turn, from where you started. It should level somewhere within that range. You may have to adjust further, but you should have a good idea of what way to go at this point. If your lathe has been leveled correctly, your tailstock and head stock should line up.

You are assuming that Rick has a Robust AB or some other lathe where the legs can be adjusted. I do not know what other lathe has that feature.

 

[MichaelMouse]

You are assuming that Rick has a Robust AB or some other lathe where the legs can be adjusted. I do not know what other lathe has that feature.

ALL do. Prethreaded leveler or wedge, makes no difference. Steal the gap, end the motion.

 

[Bill Boehme]

ALL do. Prethreaded leveler or wedge, makes no difference. Steal the gap, end the motion.

Almost all. I forgot that all decent lathes have leg levelers. My previous Delta wasn't exactly what one might call "decent".

 

[hockenbery]

You are assuming that Rick has a Robust AB or some other lathe where the legs can be adjusted. I do not know what other lathe has that feature.

The ONEWAY lathes, Stubby, and Robust all have adjustable leg height. There are others as well.
I had my Woodfast bolted to the floor. It has a narrow footprint.
When I got a 2436 I never felt the need to bolt it to the floor. The "A" frame legs give it a wide footprint.
As long as the lathe is leveled it stays put. My 2436 weighs about twice what the woodfast does.
The American Beauty has a similar wide footprint.

Al

 

[Bill Boehme]

The ONEWAY lathes, Stubby, and Robust all have adjustable leg height. There are others as well.
I had my Woodfast bolted to the floor. It has a narrow footprint.
When I got a 2436 I never felt the need to bolt it to the floor. The "A" frame legs give it a wide footprint.
As long as the lathe is leveled it stays put. My 2436 weighs about twice what the woodfast does.
The American Beauty has a similar wide footprint.

Al

See my post directly above your's.

 

[musky]

Bill, hopefully I read his post right, as it looks as though he stated that he has a Robust AB.

 

[Bill Boehme]

You are right. I re-read it and see it hiding inside a pair of parentheses. It's funny that I read it several times and never saw that.

 

[Steve Worcester]

The Ab is a breeze to level. I don't believe in bolting lathe down because when it come loose, it is without warning and catastrophic.