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View Full Version : Making a vertical lathe - and very large bowls



Arron
30th November 2014, 06:56 PM
This is an idea I'm thinking about but because I have no real engineering experience I thought I'd reality-check it here. If its a rubbish idea, please tell me before I expend any more precious thinking-time on it.

Anyway, a few years ago I bought an inexpensive lathe and got into wood turning. I did turning for about 6 months before giving it up - making some quite nice things - but ultimately deciding there were enough dog-bowls in the world already. The one thing I remained interested in however, which I would still like to pursue, was making some really large bowls - I guess I'm meaning 500+ millimetres across, maybe up to 800mm.

I have all sorts of ideas about large bowls which look good in my mind (probably not in practise but we will see and thats the fun of it).

Obviously you cant make something that big on an inexpensive lathe - the distance from bed to centre would stop you if nothing else.

So I'm thinking of perhaps making my own lathe.

Most of my mega-bowl ideas are not what you would call finely-featured forms. Thats good, because it steers me away from a high-precision engineering solution.

Thinking about making a lathe means going back to scratch. As I'm only interested in making a lathe suitable for very large bowls (no turning between centres stuff) I have wondered if the best solution is a vertical lathe. I did a search for vertical lathes for home-oriented wood turning on the internet with no success. This seems odd as I doubt I'm the first person to think of it.

So I guess its a lathe like a potters wheel - but larger and very much more robust as its turning very large bits of wood.

The advantages I can see are that:
1. You would be able to turn a very heavy object (subject to motor size) without gravity playing a negative role. This means you have more tolerance in terms of engineering precision, bearing quality etc. Thus it should be easier to make.
2. You could have a very wide, flat platen (the wide horizontal plate which I see the blank sitting on), which would enable you to have all sorts of holding mechanisms for these large blanks. The blank would sit on the platen with great stability.
3. There could be a safety angle. There is little risk of the blank coming loose and hurting you because its already (in a sense) fallen as far as it can.
4. There would be no limits on the size of the object you could turn, except perhaps motor power.

Out of these, point 1 is the main one. It seems to me that building a lathe to turn heavy object with a horizontal shaft is wrong, because the object is putting immense downward, and therefore lateral, pressure on the shaft.

So what I'm thinking about is making something with:
1. A low robust and rigid table made out of angle iron.
2. a metal top to the table.
3. a 2hp motor bolted to the legs of the table.
4. a central spindle, mounted to the table top, piercing it vertically, and with a pulley on the bottom.
5. a belt between the motor and the spindle, preferable with gearing for different speeds.
6. a big wide platen on the top of the spindle - say 600mm wide. This is the bit the blank sits on.
7. a bearing race towards the outside of the table, directly supporting the platen. Probably a dozen or so bearings - maybe these : http://www.amazon.com/Bearing-6201RS-Sealed-12x32x10-Bearings/dp/B002BBJSO0 .

The bearing race would take most of the downward force. They would need to be on adjustable shafts, so they could be raised or lowered a tiny bit to make sure all bearings are in contact with the platen. They would need to be in a circular arrangement - so the platen rides smoothly on them. They would need to be somewhere towards the perimeter of the platen - but basically at the point where they provide the most support with the least platen flex. These take most of the downward pressure, so the shaft takes very little pressure and is basically just providing turning force.

So is this idea any good, or is it rubbish ?

Arron

Pat
30th November 2014, 08:30 PM
So you want the work piece to be horizontal, you having to lean over the piece to shape it, be in the line of fire . . . . You would have to be able to fix your blank to the platen in both orientations, as a big blank has terrific centripetal force even at low speed (<50rpm). Also, how high is the lathe? I have a stuffed back, so leaning over a workpiece for any length of time is out.

Just a few questions. Have you drawn up a plan? Looked at the physics?

Not saying it's impossible, but maybe not efficent or practical or safe.

dougturner
30th November 2014, 08:36 PM
I have only been turning for about 26 years, and have made bowls/platters 500mm and larger over that time. A dedicated bowl lathe is available from several different sources, and many have made their own, but I have never seen reference to a "vertical" lathe. Maybe all those points you made seem valid to you, but a normal wood lathe with beefed up headstock bearing arrangements and a heavier shaft will do the job. The only other comment I have is, that I hope you have very strong and long-lasting back muscles and spine, to cope with all the bending your "vertical" lathe will force you to do. A dedicated bowl lathe, or even one with a swivel head, will allow you to turn larger bowls and platters in a great deal more comfort, standing right in front of the piece you are turning. Good luck! Doug :U.

DaveTTC
30th November 2014, 09:15 PM
A vertical lathe is something that has been thought of at some level. There are attachments you can get to use a drill press as a vertical lathe.

What you say about gravity and balance makes a lot of sense. However while this might be good for holding the work you would be fighting against gravity in using your tools.

Either way I would be interested in following what you do. I imagine an 'L' shape tool rest to hold your chisel up and to hold it against rotational force at the same time would be in order.

Relatively cheap would be a basic swivel head lathe which would let you swing a larger bowl along the length of your bed.

oreos40
1st December 2014, 12:08 AM
1 there is no getting out of the line of fire.
2 unusual tool positions holding the tool above the work rather than at your side as the depth increases or decreases
you would be stooping or on a ladder.
3 bending overt he work I didn't think of originally until I thought about holding the tools and getting the swing you
may want to use on the handle good chance for a catch to clipp one in the head.
4 fixture would be the same as on a horizontal set up



For platters have you considered a "T" shaped lathe?
for bowls it is hard to beat several of the inexpensive yet very robust DIY designs out there.

jhovel
1st December 2014, 02:48 AM
The issue - as many previous responses pointed out - is that using a HAND-HELD tool is always going to be too dangerous. However, in metalwork, vertical lathes are common for large objects: https://www.google.com.au/search?q=vertical+lathe&num=50&safe=off&rlz=1C1CHMO_enAU575AU575&es_sm=93&tbm=isch&tbo=u&source=univ&sa=X&ei=-jd7VNq6OcPv8gXGrILIAQ&ved=0CCwQsAQ&biw=1366&bih=643
If you were thinking of mechanically positioning your cutting tools then this is not such a silly idea.
The other option is to use 'live' tools (a router for example), positioning and holding that mechanically and using very slow rotational speed might make for a whole new concept!
On the other hand, large bowls are turned the 'conventional way' too: https://www.youtube.com/watch?v=VEO43Zo6CbY

Arron
1st December 2014, 07:05 AM
The issue - as many previous responses pointed out - is that using a HAND-HELD tool is always going to be too dangerous. However, in metalwork, vertical lathes are common for large objects: https://www.google.com.au/search?q=vertical+lathe&num=50&safe=off&rlz=1C1CHMO_enAU575AU575&es_sm=93&tbm=isch&tbo=u&source=univ&sa=X&ei=-jd7VNq6OcPv8gXGrILIAQ&ved=0CCwQsAQ&biw=1366&bih=643
If you were thinking of mechanically positioning your cutting tools then this is not such a silly idea.
The other option is to use 'live' tools (a router for example), positioning and holding that mechanically and using very slow rotational speed might make for a whole new concept!
On the other hand, large bowls are turned the 'conventional way' too: https://www.youtube.com/watch?v=VEO43Zo6CbY

Yes, I did intend to use some method of mechanically positioning and holding the tool. This was going to be the subject of a second post - I was keeping the topics separate in the hope of concentrating on the engineering aspects of spinning the bowl first. I can see now it probably wasnt the best way to approach the subject.

I am interested in a mechanical tool holding because I have Injuries to my hands and arms which make prolonged holding of turning tools too difficult.

However, some good points have been raised. I cant help thinking that even if a mechanical cutter did most of the work I would still need to do plenty of finish work with hand tools and I dont think that would be possible.

I also doubt my ability to make an effective tool holder.

Its starting to sound like a misguided attempt to reinvent something that doesnt need reinventing. Thanks for the guidance so far.

Cheers
Arron

oreos40
1st December 2014, 08:02 AM
Now you are moving into an area that I have some experience! My dad started out using converted metal lathes in the late 1940's. He ran a production wood turning business for over 60 years. The lathes I have built are a little different. all can be used freehand but they are made to be copy lathes. they are not CNC. I use a typical tool holder for a metal lathe and typical tooling for metal but sharpened for cutting wood. the cross feed screw is replaced with a lever and a template is mounted behind the bed for a finger on the cross slide dust cover to follow. I have adapted lathes for the physically challenged with specialized tooling and user specific adaptations. I would be happy to help any way I can.

Rod Gilbert
1st December 2014, 08:04 AM
Hi all, Sounds like we are getting into the likes of Stephen Hogbin who was mentioned in an earlier post he did a lot of experimental (out there) work on extremely large turntable with an articulated arm with a router attached to the end of the arm. He made some really wild sculptures on it. There were several photo's as I recall in the book he did while here in Australia.
Regards Rod.

Lyle
1st December 2014, 12:31 PM
Try thinking about a truck differential and rear axle. They would be strong and depending on the ratio maybe turn the wheel hub with a motor, effectively reversing the ratio. eg one turn of tailshaft = 3 turns of wheels. therefore 3 turns of the wheel then only 1 turn of tailshaft. There would be ways to easily mount a faceplate and driving attachment for wheel/axle. as the diff and wheels are mounted to a vehicle body they should be able to be adapted for a solid horizontal mount, to have the tailshaft end vertical.
I hope you can understand the idea. I know others have used this method for large horizontal turning, so adapting it for vertical shouldn't be too much more.
Lyle.

ACT_Grumbles
1st December 2014, 01:30 PM
It strikes me that there are two major issues.

1. It is easier to balance a blank vertically when it can freely fall to the bottom.
2. Waste falls off a "normal' lathe - a vertical lathe work area would always be choked with sawdust unless a blower or DC can be attached.

Comments from other members are equally valid - if you are re-engineering a CNC machine, limiting it to a single axis rotary table seems a backward step.

Attaching a conventional rotary table to a Wood Wizz would seem cheaper and more capable.

Best of luck!

oreos40
1st December 2014, 01:30 PM
Try thinking about a truck differential and rear axle. They would be strong and depending on the ratio maybe turn the wheel hub with a motor, effectively reversing the ratio. eg one turn of tailshaft = 3 turns of wheels. therefore 3 turns of the wheel then only 1 turn of tailshaft. There would be ways to easily mount a faceplate and driving attachment for wheel/axle. as the diff and wheels are mounted to a vehicle body they should be able to be adapted for a solid horizontal mount, to have the tailshaft end vertical.
I hope you can understand the idea. I know others have used this method for large horizontal turning, so adapting it for vertical shouldn't be too much more.
Lyle.

the differential is a reduction from drive shaft to wheel the drive shaft makes more turns than the wheel does. I used one for a machine to cut granite circles up to 8 feet in diameter and it was set so the granite was horizontal.

tea lady
1st December 2014, 04:01 PM
On a "normal " lathe gravity is actually helping you do the turning as the wood is falling on the tool spo to speak instead of you having to push the tool down.

But having also done pottery and turned the foot of bowls maybe it would work. The chisels would need to be differant through. In pottery the tool is a loop tool with the blade perpendicular to the handle. Like the hook tools that are used to do bowls on pole lathes. And you might need to sit like a potter to do it.

Holding the tools like a metal lathe would be taking all the fun out of it for me.

DaveTTC
1st December 2014, 06:05 PM
If you want to trial it before a major commitment you could mound a mini lathe on its end and jut try some stuff first

I actually love to see someone trying something outside the box


Dave the turning cowboy

turning wood into art

Paul39
2nd December 2014, 04:33 AM
Proserpine Big Bowl. Their web site is down, do a Google search and talk to some turners about the big bowl.

http://www.woodworkingtalk.com/attachments/f6/29131d1316744819-really-stupid-question-turning-big-stuff-lathe_without_driver.jpg


http://www.woodworkingtalk.com/attachments/f6/29132d1316744840-really-stupid-question-turning-big-stuff-john_d_with_base.jpg

http://www.woodworkingtalk.com/attachments/f6/29133d1316744853-really-stupid-question-turning-big-stuff-ready_for_turning__2_.jpg

hughie
2nd December 2014, 09:58 PM
So you want the work piece to be horizontal, you having to lean over the piece to shape it, be in the line of fire . . . . You would have to be able to fix your blank to the platen in both orientations, as a big blank has terrific centripetal force even at low speed (<50rpm). Also, how high is the lathe? I have a stuffed back, so leaning over a workpiece for any length of time is out.

Just a few questions. Have you drawn up a plan? Looked at the physics?

Not saying it's impossible, but maybe not efficent or practical or safe.


....and not to mention it will be damned awkward to use. Search the forum there a number of home made lathes project listed some with a blow by blow posting.

Paul39
3rd December 2014, 01:17 PM
No bending over or straining, just crank the tool down.

1914 Niles Vertical Boring Mill

http://www.practicalmachinist.com/vb/attachments/f19/123038d1417147996-niles-36ft-vertical-boring-mill-photos-niles-vbm-2.jpg

http://www.practicalmachinist.com/vb/attachments/f19/123039d1417148039-niles-36ft-vertical-boring-mill-photos-niles-vbm-operator-platform-1.jpg

DaveTTC
3rd December 2014, 02:02 PM
I want one of them .... that is awesome!!!!!!!!!


Dave the turning cowboy

turning wood into art

Uncle Al
3rd December 2014, 02:18 PM
I want one of them .... that is awesome!!!!!!!!!


Dave, You'll need a few lengths of rope and a couple of mates to help you load it into your ute:D. Might also pay to put a bit of extra air in the rear tyres.

Alan...

Paul39
3rd December 2014, 02:21 PM
DaveTTC,

Niles VBM Thread, you have to join to see the photos:

http://www.practicalmachinist.com/vb/antique-machinery-history/niles-36ft-vertical-boring-mill-photos-294807/

Here is your chance, from the same thread with the photos:

There was a similar sized boring mill laying in pieces in a warehouse where the company I worked for rented space. It came out to the Harnischfeger Corporation in Milwaukee. It was purchased by the University of Wisconsin when they were bidding on the Super Collider Project that eventually went to Texas. Finding they had no use for it they sold it at an auction. The buyer thought he was going to make a killing by selling it for scrap. Over the years he hired several companies to cut it up, but all of them failed. He finally had a consultant come in to determine what had to be done to break it into small enough parts to send it to the foundry.

The consultant determined the castings were so thick the cheapest way to break it up was to use directional explosives. However the cost of disassembling it and breaking it apart was going to exceed the scrap value. The last I saw it was 8 years ago still laying in the warehouse. The owner had defaulted on the storage payments so it became property of the moving and storage company that owned the building. As far as I know it's still sitting there taking up acres of space because it's going to be more expensive to dispose of than it is to leave it set.

BUT!!:

I'm sure if it's still there you could have it for the asking. Keep in mind however it took a long reach 100 ton crane to get the pieces off the trucks it took to bring it to the warehouse. The trucks were also specialty trucks normally used in the foundry business. The tractors had 3 drive axles. while the trailers each had between 4 and 6 axles under them depending on the size of the part(s) they were carrying. Don't forget to apply for the oversize/overweight permits, and make arrangements for the guide vehicles before you go to pick it up.

AND!!:

Was offered a HBM with a 12ft square table several years ago for free. Scrap company had been given it and it wasn't worth hauling back to scrap. All I had to do was go get it... and prepare a foundation for it, and a building it would fit in, and provide electrical service, dis-assembly/assembly crews, big crane rental, and the aforementioned monster tractor trailer rigs with escorts to move it, then reverse to put it wherever I wanted it. Figure $300,000 for a good start.

DaveTTC
4th December 2014, 08:14 AM
what a travesty to see something like that considered for scrap


Dave the turning cowboy

turning wood into art

Boydage
28th September 2016, 06:11 PM
Hi. I looked at your thread and a few replies. I am an engineer and a woodworker. Having been in woodworking for many years and now playing with CNC routers and lathes I can understand where you are at.

In all honesty I can see the advantage of a slow speed spindle using a small router for your cutter instead of conventional lathe work using chisels against rotating timber for your cut. If it was me, I would be setting a small router on linear rails with hand rotated screws able to move up/down and in/out to create your finished product. Then you can rotate your workpiece at a slow speed and still get a great finish.

But if you are looking at rotating heavy large pieces of timber, DONT mess around with little baby tiny bearings. Also remember to research the difference between roller and ball bearings due to what they are to be used for. Keen to see how you get on.

ian
29th September 2016, 01:12 PM
Hi. I looked at your thread and a few replies. I am an engineer and a woodworker. Having been in woodworking for many years and now playing with CNC routers and lathes I can understand where you are at.

In all honesty I can see the advantage of a slow speed spindle using a small router for your cutter instead of conventional lathe work using chisels against rotating timber for your cut. If it was me, I would be setting a small router on linear rails with hand rotated screws able to move up/down and in/out to create your finished product. Then you can rotate your workpiece at a slow speed and still get a great finish.
me thinks a regular CNC would be a lot easier to set up and control if working horizontally