Possible problem.

[Swarf_Newbie]

(12-20-2019, 10:07 PM)Highpower Wrote:

(12-20-2019, 08:28 PM)Swarf_Newbie Wrote: So approx .3mm runout, this is pretty much the same with ALL stock used, so it can't be a bent bit of steel, or am I missing summat?
If I zero at tailstock end, I get approx. .3mm run out at chuck?????  

Thanks in advance folks.

Roy.

Roy, I'm not sure I am understanding your method of checking the run out of your stock. Are you measuring two random points 180° apart? Please clarify. Also you've said you have .3mm run out at the tail stock end. What are you doing with the stock exactly in order to then "zero" it at the tail stock end?  

Zero stock in chuck, rotate 360 deg, still zero yes! (I thought it was easier to just show two points 180 deg apart)

Move carriage to end of stock, zero should(technically be zero yes?) rotate through 360 deg, I now have .3mm runout.
(I have problems explaining exactly what I mean, cos I'm still a newbie!! sorry  )

If I then adjust  zero at end of stock, I then have .3mm of runout at chuck.
Does that make more sense?
 Now I would not think that 10mm silver steel 300mm long would flex that much under the pressure of a dti? but I could be wrong!   
Go easy on me guys............learning way to much to keep in my old brain at the same time!   

Oh, and a Merry Xmas and a Happy New Year to all on here!

Cheers.

Roy.