large lathes

Re: large lathes

JL work

>How would you get chips out of the center? You would have to have a heck of a cyclone or DC.

Re: large lathes

john Lucas

>Sounds interesting but chip clearance of bowls could be a problem. Also holding the gouge to cut the inside would be interesting. Where would you put the tool rest?

You would be side loading the bearings and I'm not an engineer but I don't think most bearings are made for that.

I think you are still spinning the same mass so the horsepower would be the same with the possible exception of an out of balance mass.

I like your thinking however. Outside the box. Keep thinking that way you may come up with the next generation of lathe. Like I said I'm not an engineer and there may be a logical reason to do what you suggest.

Re: large lathes

gil in san diego

>I would get the chips out of the center by scooping, sucking or blowing. An inconvenience but compare that inconvenience to a lathe that wants to be a basketball. Or compare that inconvenience to a log that you can't lift, line up or mount.

Then already make lathes that spin this way but I have only heard of them in metal shops.

Re: large lathes

gil in san diego

>The chips could be sucked, blown or scooped out of the bowl. I would rather do this than have a lathe that wants to be a basketball. The tool rest would be mounted to the lathe itself just like it is on most (smaller) lathes. If the work got larger, and the rest needed to be mounted to the floor, I guess that you would need to sink into the ground for stability - this inconvenience could range from an inconvenience to a showstopper.

"Side loading bearings that aren't made for it" - I'm not sure about this either. The solution to this problem could range somewhere from a minor redesign in bearings and support to a redesign that costs too much to allow it happen.

Yes, you would still be spinning the same mass, but the out of balance mass is one of the main problems that I am trying to deal with.

You like my thinking that is "outside the box", or "outside the bowl"? I know a mechanical engineer who is willing to entertain my stupid, or not so stupid ideas. I am not really trying to invent anything, just wondering why it isn't done. If he can tell me why it isn't done before anyone here does, I will post the reason.

Re: large lathes

John D Williams -oubaasjohn

>About the lathe on a vertical axis.

I cannot see that shavings will be a problem as the spinning of the lathe will throw them out.

BUT the tool rest and holding the tool to do the "bottom" of the bowl could be awkward. Imagine working on the bottom of the bowl with a gauge.

That said potters wheels are mounted this way...

Re: large lathes

Fog Tanner

>It seems as if you are rediscovering the wheel or lathe in this case. I went to the Dead Sea Scrolls exhibition over the Christmas holdidays. In the exhibition, there was a large stone vase/urn/container about 3 feet high and 20-24 inches at the largest diameter. It had a small foot with a cove inbetween. The sign said that it ahd been turned on a lathe. The piece was over 2000 years old. In studing the piece, the only way it could have been turned was on a vertical lathe, as it would have snapped as soon as the cove was cut. This was no light weight piece of stone, limestone I beleive.

The lathe must have been something like a potters wheel with a vertical tool rest. And one can only surmise the hollowing setup they used. Vertical lathes are common in large machine shops that to oil field equipment. There are pices that cannot go on a horizontal lathe. These typically have a large rotating table that the piece is clamped to, like a very large face plate. These are also relatively low rpm machines and you are machining steel which doesn't tend to fly apart. That would be the downside of a vertical wood lathe, you can't get out of the blast path. And the working height would put that somewhere around your chest area. This would probably be the one lathe where I would use one of those wire cages around the piece. But, the idea is still appealing for those really large pieces that are really difficult to handle by yourself. If nothing else, it would make a nice machine for getting a piece into a round blank for remounting on a horizontal lathe.

Re: large lathes

Scott Thorburn

>Thinking about it for a bit I have the following comments.

1) I think you would still likely need to lift it. Fine adjustments needed to move the piece from your ramp to a correct centered position are easier if you could lift it rather than try and drag it along the face plate or drive center. Lifting would be easier with a block and tackle.

2) If you bought the right type of bearings ( A lazy Susan type bearing), there should be no problem either orientation. Bearings are made to handle the stress in a horizontal orientation ( If the bearings are chosen correctly)

3) In theory would have less work to do . most of the mass would be supported by the bearings.

4) Dismounts as you put it ( or flying bowls as I would refer to it) would happen with the same frequency. The dismounts are not caused by gravity but by the centrifugal forces of the work piece. And of course by some thing going wrong. ( to high a speed , fault in wood or a catch) The one difference is the dismount can go in any direction. There is no gravity to eventually bring the object down to the ground.

5) The real problem I suspect would be in tool handling and ergonomics.

I do not see any advantages to a orientation change, that I block and tackle wouldn't solve. Just my Humble opinion of course

Re: large lathes

Sam Dean

>I don't think bearings would be a problem - they make them to handle the thrust. However, I don't think that a vertical set up would help the out of balance situation, or take any less horsepower. Once the surface speed of the side of the bowl accelerates past the speed of gravity, it wouldn't matter which way the blank was spinning. Centrifugal force would take over. (think gyroscope). With that said, an out of balance blank is an out of balance blank, regardless of which way it's being held. The same could be said for horsepower requirements; ultimately, it wouldn't matter.

BUT, the loading - mounting situation would be much better! Even if it was just used to make something round to mount on a conventional lathe, with a monster bowl blank that could be a life saver. The tooling could even be set up like a metal lathe with multi axis adjustment and a standard cutter head. I'm going to put some thought into this one.........

Thanks,

Sam

Re: large lathes

Ken Grunke

>When you're turning a bowl or hollow vessel, you need access to a fairly large area beyond each end, but especially at the end being hollowed. If you were to be able to raise and lower the lathe to a convenient height for any particular cut, AND flip the lathe end for end, then it might be worthwhile.

Myself, I'd likely use the lathe in the horizontal position!

Re: You've asked, "what am I missing?".

Al Crandall

>I think you are missing the problems with hand turning a vertically spinning large hunk of wood. I can't visualize a comfortable tool rest to use with your proposed set up. The cuts would be made while raising or lowering the position of the gouge on the tool rest and simultaneously pushing it in or pulling it out of the plane of work. Gravity would be working against the hand held gouge every moment you are using it. Tool rests are repositioned often while shaping the outside. They stay where they are when loosened until you move them and relock them. A vertical spindle would mean that the rest would try to fall to the ground as soon as you loosened it. I believe the ergonomics of using the machine trump the ease of loading it.

Vertical? Already invented !  *LINK*

Fred in NC

>


Vertical Woodworking Lathe

Re: Vertical? Already invented !

Fred in NC

>And, do a Google search with "vertical lathe" (with quotes) and you will be amazed at the results.

Re: You've asked, "what am I missing?".

Leo Van Der Loo

>How hard is gravity pulling when you are chasing your unbalanced lathe around the studio, try spinning a rope with a 5 pound weight on it, makes no difference, horizontal or vertical, and bearings are made for radial forces, truck wheels with 5 tons of load going 60 miles an hour down the bumpy road do get a fair amount of up and down forces applied to them I would think, and last for hundreds of thousands of miles, and rolling a bowl blank up to a horizontal or vertical platform should also not make for much of a difference, and I also think it is easier to go and sharpen or change your turning tool when you don't have to crawl or clamber off of your platform, turning your horizontal turning bowl.

Have fun and take care

Leo V

Re: large lathes

Georg Waldhof

>I've actually used a verticle lathe (though not a large one), a horizontal type (typical) and potter's wheel. Pretty radical differences between all three in practical use.

As some have noted, when using a vertical lathe the ergonomics are very different, and frankly I found them to be pure hell. The strain on the body working top-bottom-top and the tendency to tilt so that the work "appears" horizontal puts an aweful strain on the body - particularly neck and back.

Horizonal is rather comfortable and natural, and the body can be used to guide the tools down the rest. Even working outboard the body is in a comfortable position and body weight can be used to work the form.

Pottery wheels are a radically different animal. The body is in an upright position and the hands manipulate the clay from the sides, etc. This is a very different process than working with a cutting tool against a solid immalleable object.

The large vertical lathes used in oilfields generally are not used with handtools (as far as I know).

Tossing a block would occur just as frequently. At least with a horizontal lathe you know it will at least start out going perpendicular to the horizontal axis. With a vertical, it will do the same thing, but the floor is also perpendicular to the axis. Roulette wheels come to mind.

I can certianly see that loading might be a bit easier. On the other hand, what happens when you are leaning over an into a large spinning bowl clearing the inside? I'm thinking about even the slightest hanging cloth which could catch on the bowl edge which could result in something like leaning onto a saw blade or catch and throw the turner. Roulette wheel again, with different ball (no pun intended).

Anyway, I will admit that the vertical lathe I used was a small version, not a mega lathe, but I do think that the machines have evolved the way they have for a reason.

Not that we shouldn't sometimes mutate the evolutionary process ;-)

Have fun

Re: large lathes 

gil in san diego

>

Hey now!

TD

>Now you are tampering with perfection. Stand the thing up and go to work; you got all you need to do anything that comes to your mind. lol

TD