Easiturn Bow in bed, manufacture tolerances or warped!

[Adee]

Hi
Just bought one of these Easiturn Lathes, nice bit of hobby kit.
I was leveling the bed up over the weekend, with a precision level (shows .001” over 10”)
From back to front I leveled the bed to about .001”, 0 reading in centre and about .0005” each end, so got a little bit of a twist, but can live with that.
But when I came to level the length of the bed, big errors!
I got centre of bed, well roughly centre reading 0, then roughly .003” plus at either end.
So looking at a saggy middle.

Can anyone tell me if these type of errors are satisfactory, if not any Ideas how I can true the bed up.
The above readings where obtain after adjusting the machine’s feet to get the most equal readings.

Adee

[SimonRafferty]

I think that's reasonable. You will probably get that kind of tolerance change between summer and winter due to thermal expansion, or by varying the torque of the bolts that hold it to the stand.

In practice, it's rare to be machining something the whole length of the bed and unless the workpiece is pretty chunky and between centres you'll be lucky to stop it sagging by a thou or more.

I suppose you could fabricate yourself a little screw-jack to sit under the middle of the bed to lift it up a tiny bit?

Si

[Adee]

Hi yeah thats what I was thinking something to jack it up a bit, was just wondering what other easiturn users/owners had found, Im more used to larger cnc lathes and normally errors on this scale would be put right.

cheers for the response.

[SimonRafferty]

Although I don't have a particularly precision level - I reckon mine 'sags' in the middle by about 1.5 thou.

From my point of view - that's fine - but I did wonder if just changing the torques of the bolts which hold it to the bench might make that much difference - if I get particularly bored, I'll give it a whirl!

Si