I'm thinking about building a large bowl lathe that will handle a 36" workpiece. The bearings and spindle will need to be heavy duty, but I'm not sure what I should be looking for in selecting mounted bearings to hold the spindle. I believe ball bearings are the way to go, but what do you think? What do you think would be a good load value for the mounted bearings? Here's a link to Grainger that lists several:
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I don't have the spindle yet and I'm not sure if I should get the bearings first, then the spindle, or vice versa... One option I'm thinking about is to buy a spindle and/or bearings from one of the lathe manufacturers, but I'd like to see what other options might be more affordable from you smart people. Thanks for any input!
Well, first off, don't use balls for a lathe this big - use tapered rollers. If you choose tapered rollers that happen to be the same as a common car or truck front wheel, they might even be affordable.
Pillow block or flange bearings will make your job of making a lathe much easier! Only the bearing near the bowl needs to be a roller bearing, to handle the thrust. The other end just keeps the shaft inline. I used a double row roller bearing near the workpies and ball bearings on the far end.
You can find these on eBay, btw.
For 36" bowls a 1.5" diameter shaft is minimum. Many large bowl makers to larger, up to 2.25".
Ever hear of the Serious Lathe. It was sold a few years ago, and is resurfacing. I was at a meeting of the Umpqua Turners in Roseburg, and the owners were there. They have a separate assembly that is removable from the headstock (bearings and spindle) in the event that the bearings fail. It is heavy duty, and made to turn up to 30 or so inches in diameter. I don't know if they would sell just that assembly or not. robo hippy
The Serious Lathe headstock is a nice piece of work. But if you want to go the cheap route, get two 2 3/16" i.d. pillow blocks, ball bearings, and mount them something like 12+ inches apart. 16" won't be too far. The spindle should be a 2 1/4" diameter piece of 4140. Threaded 1 1/2x8. This is a standard spindle thread and therefore you can use accessories like chucks without any additional machining. However, I suggest that you drill thru the spindle for knock-out bars and also for using a vacuum system.
At the loads we woodturners put on these bearings, single row ball bearings are perfectly ok. Tapered roller bearings are indeed higher capacity, but it is like using a deuce and a half to deliver pizza. Indeed, rather than use grease on the bearings, 10 weight spindle oil should be used, as the bearings will run cooler with the spindle oil than they will with the grease. Also, they will last longer!!
Standard ball bearings will withstand any end thrust we woodturners will put on the shaft. Indeed, I rough turn my pieces between centers, and I really crank down on the tail stock with absolutely no problem happening to the bearings. Plus, I have been doing this more than 20 years on the same bearings. However, one word of caution--use domestically made bearings, not the ultra cheap Chinese crap.
Just to clarify, I have turned pieces up to 48" in diameter, and pieces that started out weighing around 850 lbs, plus thousands of other pieces more normal size, and the bearings (single row ball) are still in good shape.
Clearly the idea of building a BIG bowl lathe is attractive. And, there isn't much to mounting a huge spindle with huge bearings, some way to support a tool rest -- it shouldn't cost too much money.
But, you may find that while you have a lathe capable of turning a 36" bowl blank, you are going to be most uncomfortable using it for things that big. Since you have no provision for tailstock support, you need to mount it on a faceplate. A couple of hundred pounds of unbalanced wood (even if you saw a perfect circle, it will be unbalanced because of the difference in density between heart and sap wood) supported by a handful of screws -- well, I wouldn't be all that comfortable with the idea.
I would make the same comment for those lathes where the headstock rotates or slides to the end of the bed -- no tailstock support when you are turning a big piece and need it most.
Further, as John Jordan points out often, if you start a blank between centers you can shift either or both ends to improve the aesthetics or work around a defect as things develop. When you mount a blank on a faceplate you have pretty much done the deed.
Now, my lathe will swing a 30" blank between centers. It costs a lot more than the home-brew solution but what is your safety worth?
Further, if you have some metal skills and weld and have access to surplus steel, building the headstock is not much of a problem. Designing and building a proper system to support the banjo and tool rest, one that is both up to the task and works effortlessly and smoothly is a more complex job, I think. In the end, this is going to make the difference between a lathe you want to turn on and one which makes turning a chore.
Here's a few links that show what you might need to turn really large wood. And no you don't need a tailstock, any of those with tailstocks I know off will roll sideways as soon as the wood is to starts turning.
Hi Mike, You asked for help from smart people, but I'll chime in anyway. Most people that I've heard of who build and continue to use very large home-shop built lathes are very experienced with using both heavy machinery and heavy timber. They are usually dedicated to a special limited part of the craft and accept the expense, danger and complications of using and maintaining a large purpose built machine.
The others usually end up selling their monster at a loss and buying a commercial lathe that's professionally designed and engineered for work that's of a large but reasonable size. These lathes are versatile and allow for turning small as well as large work, whereas most shop-made purpose built 'big' lathes do not. I wonder, except for a very few of us, if a huge revolving shaft, regardless of the bearings it's in, that has no integral bed, tool rest or tailstock is really a lathe.
Bill, I think the real value in swivelling or sliding headstocks on ordinary 12" to 16" lathes is the convenience in hollowing work of a size that was started over the bed and also the ability to rotate the work the other way for ease in turning on the headstock side of the piece. I doubt these lathes were engineered for turning work much larger and heavier than the ways allow. Others' experience will differ, but I bet they are either very experienced or very inexperienced woodturners. :)
Since you've come up with some sites with big lathes, the following might be worth looking at: . As I recall, this thing has something like a 95 inch swing and is a real monister. There specs and several photos at the link.
Hi Fred, That's certainly an exceptionally well made shopbuilt large swing lathe. Was the tailstock ever built and did the freestanding toolrest work out? Did it ever swing a 96" blank? Also a little more about Michael's use and the history of this fine custom lathe would be interesting.
entitled, "Stronghold hold steady as a rock" and "There is no indication of any destruction caused by the Stronghold chuck !!!". I've never seen a chuck hold a workpiece that big. Wow. I'm guessing sharp chisels are a must. How many times would you guess you sharpened your chisels on the bowl in the pix above? How do you mount the bowl months later when you finish it? I'm guessing the mortise has warped enough that it needs to be dressed some kind of way. Yes/no?
Wow...
Mike
P.S.: Wow... Did y'all see the size of those th> Hi Mike
I put that information up on my web site several years ago and have had no more contact with the author of the information. His e-mail address at the time of posting is on the page, but no guarantee that it is still good.
Yes I think I have seen that one before, seem to recall it as painted orange, or maybe I have it mixed up with another one There are some more large woodturning lathe builders, Jerry Blanchard build some with truck transmissions to give him the all the different speeds, Jim Thomson is another one, James R Johnson made one with a riding lawnmower transmission for variable speed, and turned some real nice very large vases/hollow forms.
And yes building a large lathe is one thing, but turning large hollow forms is another thing al together, at 30, 40, 50, or even 60 RPM, waiting to have that bump to come around again and take another sliver off, and don't move that tool to much, for another sliver and another and so on.
Also cutting wood closer to center, you have to hold that tool right or it tears instead of cutting, and one better have a lot of patience getting that wood cut out.
As one with not that much patience, Richard Raffan said one is enough !!
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