Installing a new lathe

[Howard LewisParticipant @howardlewis46836]

Hi Robin,

Sorry to be so long replying. Have not looked at this thread for some time.

A lathe will have a Vee on one side, with a flat way on the other for the Saddle and/or tailstock.

(Mine has one Vee/Flat for the Saddle, and another, as a mirror image for the Tailstock).

A Lathe with flat bedways provides lateral location for the Saddle and Tailstock against the shears (vertical sideface )of the bed. So any wear will mean that the Saddle and Tailstock can move across the bed, and so become off centre, affecting alignment, accuracy and cutting action.

Adjusting the gib strips should remove slackness, but the Tailstock would need to be readjusted to ensure that its centre line is on that of the bed and Headstock.

The problem here, is that often the bed wears near the Headstock where the Saddle runs for a lot of the time. So removing clearance here will mean that the saddle is tight, possibly unacceptably so, at the Tailstock end of the bed.

A Vee bedway, provides lateral location, so any wear should keep the lateral alignment, but will allow the Saddle or Tailstock to sink below the centreline of the Headstock. On the Saddle, the tool height can be adjusted so no great problem there.

If the Tailstock wear puts it below the centre height, parallel turning , between centres will be affected.

The tool might be on centre height at the Headstock end but will effectively rise above it as the Tailstock end is approached, causing the tool to lose clearance and rub rather than to cut.

Nowadays, many lathes are advertised as having Induction Hardened Bedways, to minimise the risk of wear.

Whilst, as amateurs, we try to be precise, as we make our our one or two offs (certainly low volume), we rarely have the need for the level of repeated and consistent precision that is required in commercial mass production to ensure interchangeability. Consequently, we can live with, and adapt to a slight degree of wear in a machine.

If the underside of the Saddle or Tailstock wear, with flat bedways, the underside can be machined, and a wearplate fitted to restore things to the original level, (possibly even compensating for some wear in the bedway).

With a Vee bedway machine, repair is not quite so straightforward.

Not that I am advocating using worn, or in need of adjustment, machines, rather the reverse, that we should try, wherever possible, to eliminate or prevent wear.

What is acceptable depends upon what level of precision and accuracy is the goal, and the availability of machinery to make it. In the days of James Watt, a cylinder bore within 1/16 of an inch was probably considered good. Today, for Fuel Injection Equipment, we are looking at one or two microns!

Howard

[Robin GrahamParticipant @robingraham42208]

Hi Howard, thanks for the clarification – I thought you were saying that the levelling procedure was somehow different for flat and V-bed lathes, which perplexed me, but I see now that you were talking about the different wear characteristics. The machine I've bought (new) has induction hardened V-ways, so I'm hoping wear won't be a problem for a while at least!

I took on board your comments about ventilation and have installed a 100m^3 per hour extractor near floor level which is doing a good job – no sign of rust on various bits and pieces I've moved down there. Next thing will be to get some heating in. A couple of wood-burners should get the place pretty toasty.

Progress – Lathe arrived last Wednesday, after much head scratching I had decided that there was no way I was going to get it into the cellar on my own and live to tell the tale. So I enlisted the help of John S whose infamous Lodge is situated not too far from me. Took about three hours of dismantling, hoisting, pallet-trucking, crowbarring, pallet trucking again to get it down there, but job done! I'm going for levelling feet (eight of them) direct onto the flagstones. When they arrive, and Axminster have sorted the problem with the badgered cross slide, the machine can be reassembled and commissioned.

My thanks to all who have commented/ given advice, a great help for a tyro like me.

Regards, Robin

[Howard LewisParticipant @howardlewis46836]

Hi Robin!

Great day when the machine arrives, even better when it is set up ready to run. Unless you are planning to use a continuous (pumped) coolant supply, I would not worry too much about the Headstock to Tailstock level.

If you are using pumped coolant, obviously, the chip tray needs to direct the used fluid towards the return to tank. Otherwise, concentrate on removing any twist from the bed, by ensuring that the level across the bed is the same at Headstock and Tailstock ends. More difficult with a V bed way, but as long as the same packing is used at both ends, you should be able to get it twist free.

The levelling mounts will help no end, screw adjusters are far better than shims, in my view.

A woodburner with an external chimney will help with ventilation, but any leak in the pipework is an absolute NO NO. You don't want any extra water vapour in the atmosphere for the benefit of the machinery / materials, and for your benefit and life expectancy, you most certainly do not want any Carbon Monoxide.

Go for it!

Howard

[Russ BParticipant @russb]

I'm way to late…….. but

550kg, is really not a lot of weight, even on dirt. If you know your own weight in Kg and imagine 5 of you stood there, nothing drastic is going to happen to the floor even if it is laid directly on the dirt – many people find with old houses, much more than just the floors are laid directly on the dirt!!

mmmmmm wood burner…… living the dream, I am green with envy! If your in a cellar, a good monoxide alarm, plus one of the old skool visible cards in eyeshot is a must. But just one thing, wouldn't the rapid change in temperature cause a potentially damp wave of warm air to condensate on your still chilly machine tools!?

Perhaps a 30 or 50w tube heater under each machine 24/7 would keep them cosy enough (just a few degrees ahead of the game!), and give background heat to the room perhaps. 30-50w doesn't sound like much, but cast irons specific heat is only 430 to 500 J/Kg.K so I'd expect throwing 30-50 J/sec past it, even with all the losses, will soon change all 550kg of it (I can't be arsed to work it out……… it's almost midnight, I'm off to bed………) throw a blanket over it too if it don't work (mine are always under thick blankets, towels etc. breathable, insulating – bit messy, can gather dust if not cleaned – especially grinding dust.)

Edit* damp not dam*

Edited By Russ B on 09/10/2014 23:51:27

[Robin GrahamParticipant @robingraham42208]

Hi Russ, not too late, when I read your post I had sort of come to the same conclusion, though it would be more like 10 of me than 5 to make 550kg! I was thinking those Victorian cast-iron baths which weigh around 150kg, say 200 litres of water and a portly Victorian gent must come somewhere near, and these are often found on suspended wooden floors I think.

Anyhow, job now done, machine is sitting on eight levelling feet direct on the flagstones. Seems steady enough. John S brought an absurdly sensitive level along and declared himself satisfied with the setup, so I'm happy.

For the rest of it, it looks as if the flags are indeed about 5" thick, and laid direct on 'dirt' – there's some redevelopment work going on to adjacent buildings and they've taken the flags up there which look to be of the same vintage. So there will be some damp coming through I guess. At the moment it's liveable with, RH was in the 90's @ 16C when we moved in, now 70-60 @ 18-21C. No rust so far!

Thanks again all for your comments on both the lathe installation and cellar renovation, Robin.

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