setting the lathe up perfectly level on floor, really?

Hi.Thanks to RNR for the reply to my last enquiry l have another it has puzzeled me for a while concerning lathes in general they say you must get lathe perfectly level on floor knocking steel wedges in if necessary and packing up on bits slate ok l will go down the slate route sounds good but l cant see the importance in being perfectly level at this stage surely if you were an eighth inch out that would be good enough after all this is stand going in then lm putting bed on stand -at this stage say l was 5degrees out and bed was showing 5degrees out level the talstock,headstock all these would have same error pointing in same direction so in theory l could leave this,l wont but after this on with head/tail stock put test bar in and clock over the top and side of bar now l would use the critical word any error showing on clock should be eliminated by shiming probably headstock and adjusting tailstock l wont be clocking cabinet true to bar l will be clocking headstock/tailstock true to bed what they are located on,not shiming under bed a guy asked if he could put his boxford on castors and told no as this would affect his accuracey l may be thinking wrong but l dont think it would his stability yes, so yes bed the lathe down but once he had performed the test bar test and was happy with his readings in theory he could wheel the lathe onto a 45 degree slope and it should cut parallel-be intrested to hear a few comments on this otherwise i,ll be in trouble when l put mine in -thanks onecut

Onecut

Most lathes are made out of cast iron which believe it or not will bend like a banana over a given length. This in turn will affect the precisions and balance. For the sake of a half hour job will save a lifetime of problems.

Paul

You are quite correct in saying that a lathe doesn't need to be level although it can be an advantage sometimes. The important thing is to ensure that there is no stress applied to the bed that can twist it. There is a nice description of how to check for distortion here

Russell.