Large Lathe

[rmm1]

Hi everyone , I am looking around for plans for a home built lathe. I already have a 20 year old ELU lathe, with approximately 1 m between centres, but I was looking for something which would turn timber posts about 10 to 15 foot long. For reasons of space in my shed, if at all possible, I would like it to be partially demountable, with the rails etc removing from the headstock for storage. I have seen commercial ones, with massive motors, both size and power, standing over 1 m high. However I would be happy to compromise on speed etc without going overboard with massive power and gears. I saw one at auction in Gatton about 10 years ago, it had a reserve of $8,000 on it, which was way above what I wanted to spend. The motor and gears would take up half a normal car garage by themselves, and I thought it was a touch over engineered if you only wanted it as a hobby. Thanks,rmm1.

[China]

I don't you will find a lathe that large that can redily be folded away, mine is a wadkin cost about $12,000 I had to source it from The UK 20 years ago.

[China]

BTW you will be supprised just how much power it takes to effectivly turn posts of that size

[hcbph]

RMM1

I see reference to length but I don't see any reference to diameter or weight of what you want to turn. Only suggestion I can make is check out Jet & Powermatic. Both have bed extensions available for their respective lathes.
Jet has a 57" & 20" bed extensions available. Longer one would take a Jet 1642 to 8' and if you could add a 20" also, that would almost be 10'.
PM 3520 bed is 34" then add either of 50" or 18" bed extensions to extend the length of it.
I have the Jet 1642 with a 20" extension on it. I've turned up to almost 60" successully but I'm afraid anything 8' or longer would be so massive I couldn't handle it.

Only other thoughts I have is that you're going to have to have a lot of power to handle something that long along with alot more than a drive center and live center to hold onto it. Additionally, I'm guessing it will have to be turned very slow.

Doesn't sound like an easy project to me.

Paul

[Jim Carroll]

12' posts are easily turned using a 1hp motor.
They do not require a lot of tourqe or speed. It is just a matter of getting the part you are turning balanced then of you go.

Variable speed works great as you are able to run the peice up to a better tunring speed. Standard pulley set up can be limiting as you are generally too slow on one set then you move up and can be too fast for the peice.

[RETIRED]

......... and 3 tonnes are easily turned with 3 HP.;)

[rmm1]

Thanks everyone for your replies. My thoughts ran along the same line as Jim Carroll.I did not think it would readily fold away,but I did not see why the rails could not unbolt from the headstock, and allow the lathe to dismantle that way.Provided you could fasten the post properly[ the commercial version I saw inserted a 30 mm bolt,20mm in diameter inserted through the headstock], the motor could build up speed gradually depending on its power and torque.Obviously, it would not match a $12000 machine in efficiency,but it should do the job,albeit a bit slower. Also quite large items can be turned on a treadle or pole lathe compared to a modern machine , although not of that size.

[RETIRED]

There is a way to do it.

Make your bed and build the headstock so that it sits on top of it similar to a tailstock and is bolted to it.

Bed extensions are fairly easy to bolt in using fish plates (like railway lines) to add strength. I have the abilty to add another 40' to mine if I need it. I hope not!:D

Accuracy is not really an issue and it doesn't matter if the tailstock is 3" out over 9' as all you want to do is turn the timber.

I have also seen a lathe without a bed. Headstock was mounted in a block of concrete and the tailstock mounted on a tractor. The toolrest was in a drum of concrete and he just moved it around.

Remember that it only has to spin the timber. As long as it held safely at each end any thing is possible.:)

This my baby.http://www.ubeaut.com.au/.htm

9' posts seems a strange hobby.:cool:

[hcbph]

Just thought of something: see if you can find a Conover lathe. You build your own bed to go with it, and you can make them as long as you want.

http://www.lathes.co.uk/conover/

Paul