Thread: Tail stock question - cast v's welded

Originally Posted by Karl Robbers

I second the "forget cast iron" motion.
I am a boilermaker who has welded more than my fair share of cast iron with a great deal of success if I may say so. Having said that, there is not enough money in the world to make me contemplate making a tailstock from cast iron sections, welded together and then machined. I can just imagine the new words in the English vocabulary created when your machinist hits a pocket of exceptionally hard material created by the welding process. If my first born was on the line and I absolutely had to do it, braze welding would probably be my approach for a number of reasons.
A good, chunky steel tailstock could be made for a fraction of the cost, (cast iron bar is not cheap), and I would challenge anyone to find fault with its properties in that application.

I'd make a pattern and get a casting done. But this wouldn't be cheap which is why, if you have no money that you're willing to spend, it's pointless saying in detail how to do it. Especially if you're going to put it on a wood lathe bed comprised of a couple of round bars. I mean, what's the point? It's going to lack both accuracy *and* rigidity.

As for steel, I'd prefer a Cast iron bottom shoe and a steel upper body if I had to go this way, but it comes back again to the fact that, if you want to make a TS for a metal lathe, you'd better have at least *some* clue about what you're trying to achieve.

Now if you want to make something that looks vaguely like a TS but aren't going to bother with minor details like having the bore on the centre line and parallel to the bed both vertically & horizontally to tolerances of say 0.0002" over 6", that's a different matter. But please don't call it a metal lathe tailstock, that's like describing something hacked out of a bit of railway iron with a cutting torch as an anvil.

Somewhere I have a book on making a wood lathe using all fabricated parts. It looked eminently do-able, including the tailstock. But it was not and never, ever could be considered as suitable for turning metal.

PDW

I want accuarate. not sure how accurate I can get. It is a wood lathe but I would like to be able to use it on some steel too. The bed it two round tubes OD about 44.5mm

Im not happy with my NOVA 3000, it is poorly machined and not very accurate in my opinion, I think I can make this old lathe better than the NOVA

Dave the turning cowboy

turning wood into art

You simply can't turn steel on a wood lathe. Spin maybe, but not turn. Your 44.5mm bar may as well be two lengths of cooked spaghetti, bar bed lathes will always lack rigidity due to their design. For turning steel you need lowers speeds, completely different toolpost etc, mass and rigidity.

As far as your T/S goes, welding one up would be easy, making the quill to suit and boring the T/S will be the fun parts. But its a wood lathe, if its out .010" it doesn't matter at all, the timber will move far more than that just from the heat imparted through turning.

Ew

Originally Posted by Ueee

You simply can't turn steel on a wood lathe. Spin maybe, but not turn. Your 44.5mm bar may as well be two lengths of cooked spaghetti, bar bed lathes will always lack rigidity due to their design. For turning steel you need lowers speeds, completely different toolpost etc, mass and rigidity.

so a dedicated metal lathe could be an add to my repitwar down the track


Dave the turning cowboy

turning wood into art

Originally Posted by DaveTTC

so a dedicated metal lathe could be an add to my repitwar down the track

Dave the turning cowboy

turning wood into art

You can turn wood on a MW lathe but unless it is dedicated to WW, switching between the two is a PITA as the wood dust and the lube needed for MW are basically incompatible.

Originally Posted by Michael G

Cast absorbs more vibration and being cast are generally have more mass so are harder to get vibrating in the first place. That's not to say that a properly designed fabricated T/S would not work but cast is probably the material of choice.

Michael

probably less man hours as well?

Originally Posted by BobL

We have an old cast iron lathe at our mens shed that has no tailstock and your description is more or less what I had in mind to replace it.

ditto....my wood lathe is fabricated from steel channel

G’day Dave,
For what it’s worth, people will line up all day long to tell you what’s not possible, to be frank, opinions are like bum holes, everyone’s got one and here’s mine.
If you really want to know what can and can’t be done you just need to have a crack and see what happens.

Can you use a wood lathe for turning metal? You bet you can, you just have to be realistic in what you do.
If you plan to take large depths of cut, seek sub thou of an inch accuracy or turn large heavy items then you really need a metal lathe.
If however you just want to put a point back on your damaged wood lathe centre, turn up an axle for a trolley or make a decorative knob for your latest creation then your wood lathe will be more than capable of the job, you will just have to be patient and take small cuts. Working in softer material like brass and aluminium will be easier but you can also work steel just as effectively.

I presume you are planning to use a graver tool on your woodturning rest because while devising and making a carriage for your wood lathe is no doubt possible, it’s probably not really worth it unless you want to prove you can.
EDIT: I see from your other thread that's exactly what you plan to do, two big thumbs up for having a crack.

As for yourtailstock, if you want quick, easy and effective, I would go with fabricating one.
If however you’re up for a challenge then you could have a crack at making a pattern and casting the body out of alloy, the type you can get from old mower bases and the like. You can do all of this yourself and if it all works out you could even take your pattern and get it cast in iron down the track and you will have learned a lot of additional skills you can use on your other projects.

Whichever option you go with I hope it all works out and good luck.
Cheers,
Greg.

Thanks Greg,

Any metal turning would probably not about what you suggest, small and minimal.

I dont know what a graver tool is but sure I will find out in short while, It is great all the in put I am getting. What I have is on old shopsmith. It is probably more of a challenge than anything else. I want to show that it could have been a better machine.

It will be long term project no doubt as I fix one aspect at a time. There is no fabricated one that I know of that is not somewhat flimsy, that is why I want to redesign it. What they do have is a carriage slide that is used for the tool rest. what I may be able to do is source another one of these and modify a fabricated Tail Stock to bolt immediately to this. Probably better this than fabricate an entire tail stock as it gives me more latitude for adjustment. If I have three fixed holes, two for the carriage ways and one for the MT they have to be spot on in every direction first time round.


Dave the turning cowboy

turning wood into art

Originally Posted by PDW

I'd make a pattern and get a casting done. But this wouldn't be cheap which is why, if you have no money that you're willing to spend, it's pointless saying in detail how to do it. Especially if you're going to put it on a wood lathe bed comprised of a couple of round bars. I mean, what's the point? It's going to lack both accuracy *and* rigidity.

As for steel, I'd prefer a Cast iron bottom shoe and a steel upper body if I had to go this way, but it comes back again to the fact that, if you want to make a TS for a metal lathe, you'd better have at least *some* clue about what you're trying to achieve.

Now if you want to make something that looks vaguely like a TS but aren't going to bother with minor details like having the bore on the centre line and parallel to the bed both vertically & horizontally to tolerances of say 0.0002" over 6", that's a different matter. But please don't call it a metal lathe tailstock, that's like describing something hacked out of a bit of railway iron with a cutting torch as an anvil.

Somewhere I have a book on making a wood lathe using all fabricated parts. It looked eminently do-able, including the tailstock. But it was not and never, ever could be considered as suitable for turning metal.

PDW

Totally agree.
At no time was I talking a tailstock for a metal lathe. As far as I knew, we were only ever talking woodlathes.
For all the reasons you mention and more, making a metal lathe tailstock is a major undertaking, requiring superbly accurate machine work.
For all intents and purposes, the only real accuracy required of a wood lathe is in the runout of the headstock drive shaft and faceplate if fitted. All cutting/turning operations being hand guided make the finest accuracy standards totally redundant anyway. Copy lathes are a bit different kettle of fish, but they still work using a medium that swells and shrinks at will.

Originally Posted by Karl Robbers

using a medium that swells and shrinks at will.

yep...bloody horrible stuff, but yet so beautiful when finished correctly...... sometimes I wish I could weld wood...