Anybody with a BIG lathe?

A while ago, I saw the web site of a guy that does architectural columns, and built a lathe large enough to do columns that were several feet in diameter, and something like 15 or 20 feet long. To rough out the columns, he used something like a 3- or 5-horse motor attached to an 18" circular blade, mounted on rails to slide back and forth. I wish I could find the link now! Maybe someone else has it...

steve

It sounds like Tom Plamann's lathe:

Finished project -

whole story - Jack Novak Buffalo, NY - USA (Remove "SPAM" from email address to reply)

I have a Faye & Scott (Dexter, ME) pattern makers lathe from the early 1900s. I bought it from a fellow turner who had the spindle threaded to 1 1/4 x 8 (RH in board and LH outboard). Replaced the flat belts sheeves with a v-belt sheeve. A 2hp motor went thru a jackshaft assembly to give a wide variety of speeds. Once I got it, I replaced the jackshaft with a 2HP VFD. I have 8ft between centers with a 16" swing. Outboard, I have a 38" swing (which is what I use 99% of the time). The rest of the bed is home to one of my Jet 1236 lathes. I can remove it with 4 bolts quite easily when I have a long spindle job to do on the big lathe. I use a Nova banjo/toolrest between centers and it has a homemade banjo with MANY homemade toolsrests for the outboard side.

Peter Teubel Milford, MA

i also run a big old lathe - no makers name on it though - it has a

9ft bed with a headstock and tailstock - i can turn approx 26 inch dianeter over the bed. the headstock has a 2.5inch shaft which was originally hollow but i have plugged it and rethreaded it to fit the faceplates and chucks that i have for my other lathe. it runs on two split brass bearings which are continuously oiled to provide a sjurface for the shaft to float on. i hva e chaged the motor to a 3 phase 3 hp which is strong enough to turn anything with good torque. i run the motor of an inverter which now means i have infinite speed control and forward reverse aswell as many other features -

i am now in the process of putting together a larger bowl turning lathe - i ma going to make it from two block bearings anmd a thrust bearing maounted on a heavy duty angle iron frame- the shaft i will have to get engineered with the appropriate shoulders etc but will thread it to suit the sturdiest chuck i can find - i will match faceplated etc with this. i am interesetd in anyone else has built such a thing and comments would be appreciated.

Rather than threading it at all, consider one of the metalworking cam-lock systems, since you're scratch-building. Nice beefy chucks available (you will need to make your own woodturning-specific jaw-tops) and no pesky unscrewing when you reverse the lathe.

My memory has slipped a little but I read of a turner who modified his homemade machine to turn flagpoles for a uni or college in either Aus or the USA. Something about trees being felled to makeway for a new building and using native wood ... the plot has been lost in the mists of time. I do remember he employed two guys just to clear the shavings (by the skip/dumpster load) photos were supplied but I cannot remember if it was a website or a magazine that ran the story ... the more I think about it the more I belive it was in Aus.

Tim GC

I turn on an old Oliver 20-C Patternmaker's Lathe and wouldn't trade it for any other on the market. I can turn 24" in diameter and almost

8' long inboard and from spindle to floor/ceiling outboard. It has a 4 step flat belt pully drive system run by a 5HP motor with 4 speed gear box. The spindle is threaded 1-7/8" x 6 tpi with #4 Morse Tapers in head and tailstocks.

You can buy MT adaptors inexpensively from Enco, MSC or on Ebay. For ~$100 I had an adaptor turned by a machinist to allow use of my 1-1/4" x 8 tpi faceplates and chucks.

The only changes I'd like to make to the old machine is a VFD for the existing 5HP motor and some sort of breaking system (poss. built into the VFD).

Are you thinking of buying one?

Turner

I worked for Thiokol, (you know the shuttle booster people), and in the exit cone facility, they had a lathe that would handle 12 foot diameter stock. It was used to lathe the exit cones for the space shuttle. It was a vertical lathe, not horizontal, and the operator rode on a lift with the tool on the end of the lift. The exit cones were approximately 12-14 feet high, made of carbon material with a fiber wrap for insulation. Very interesting watching

the work done.

I worked on one of these Olivers at a former job and wished it had VFD but the boss was too cheap. The motor was a humongous 5 hp, 750 rpm old chunk of metal and copper. I hated those flat belts, never could get a decent splice. It didn't have a gearbox, so probably not the exact model--the lowest speed was about

200 rpm which is why I wished for VFD since we were turning up to 20" dia. hardwood log chunks into African-style drumshells. I also turned a couple eccentric posts for the front porch of our house.

There's a simple way to brake any induction motor (single or three phase) by injection of DC current into one of the windings. With some type of current control, you can use a car battery as long as it's not more than twice the rated AC current of the motor. I don't have the specifics nearby, the info I have is in a book by Tubal Caine--part of the Workshop Practice Series published in the UK. I'll look it up if asked.

I'd like to find plans for a cheap DIY VFD to run a 1.5 hp 3 phase motor I have lying around. Guess I should head over to rec.crafts.metalworking and post a query.

Ken Grunke

Do you mean a build-it-yourself vfd? Buy the parts and wire it up? These things are all software driven and the code is pretty sophisticated. Also some of the parts are, I think, pretty exotic because of the large amounts of current they are dealing with.

Or isn't that what you mean?

Bill

things are all

are, I think,

Yup, that's what I meant. I spent a couple hours googling the newsgroups on the subject and came up with enough info to partly discourage me from looking any further and settle for a variable DC drive using a treadmill motor. Probably more practical for my situation, although I DO have a 3 ph. motor, and a working rotary convertor, but not much extra moola.

I'm not necessarily hoping to find a design for a continuously variable frequency convertor, a stepped adjustment in 3 or 4 ranges controlled by a rotary switch would suffice (15, 30, 45, and 60 hertz for example). A circuit made with scavanged 60's or 70's vintage parts would be ideal for my frugal style of living. A high power, very low frequency radio transmitter?

Ken Grunke

If you have 3ph available, you're half way there. Check out eBay. VFDs that take

3ph input are alot cheaper than those that can take in 1ph.

Peter Teubel Milford, MA

Well, I'm not a double-e but I play one on television...

I've been heavily into diy electronics for decades and know quite a bit about vfd-s and designing, bbuilding and programming microcomputer circuits from scratch (one of mine is running a dry kiln -- written in assembler language on a microchip cpu) and wouldn't even think of tackling a vfd. Too much current, too much smoke before I got it running and too many fried 3-phase motors. Also, no idea where to start on this one.

Bill

things are all

parts are, I think,

Hi Tim, I remember seeing that on the web and am pretty sure it was in Australia, but I don't recall enough info to do a search to find it. I think you the general idea on the details also. Martin

in message news:...

well, if i can get my hands on one at the right price, maybe at auction somewhere, yes. i look at the oneways and stubbys etc. and think that maybe the old iron would suit me better. it'll go well with the rest of the vintage machines in my shop.

jon e

Turn on a Oneway or a Stubby, than say that...

Bill

Sorry Bill,

I've turn on Oneways (all models) extensively and a Stubby once. They are both great machines, but I wouldn't replace my Oliver with one of them. I just like the stability of the Old Giant (The Oliver 20-C weighs just over 4000 pounds). With the addition of a VFD I'll have the best of both worlds.

SAFETY NOTE: This is one reason I really want a VFD... I finished one relatively small turning last Saturday morning and mounted a big snag on Sunday afternoon. I NEGLECTED TO CHANGE TO LOW GEAR and when I hit the run switch the out-of-balance snag (~100 pounds) quickly came to speed (5HP motor) and rocked the whole 4000 pound lathe! I'm sure glad I wired an emergency kill switch at the other end of the machine! ALWAYS REDUCE YOUR SPEED WHEN YOU ARE FINISHED WITH A TURNING SESSION! While a VFD won't automatically prevent this from happening, they can be programmed for a soft start.

Take it for what it's worth to you!

Turner

Soft starts are great. And, your VFD probably COULD be programmed to shut off if the load was out of balance. You could rig some sort of pendulum that touched a microswitch when the lathe began shaking. Said microswitch could be wired and programmed as the emergency stop.

Got me thinking...

Many years ago I worked for a computer manufacturer. We made a printer (1403 for those old enough to remember it) which, when it needed paper, would open its cover to let you know. The engineers thought it would save time, assure that the operator noticed the need, etc.

The problem...

The top of the printer was almost exactly the right height to put your coffee cup on and was used regularly for that purpose. So, my idea...

The coffee cup goes on the lathe. When it spills because of vibration, it shorts the contact on a liquid sensing switch...

BTW, there was always a brown stain on the floor under every 1403 printer.

Bill