On 12/27/2012 6:08 AM, SherlineCNC@yahoogroups.com
> Posted by: "Glen"moto52000@... moto52000
> Date: Wed Dec 26, 2012 10:18 am ((PST))
> I'm using 1/2 ground drill rod. I checked it on my surface plate and it looks very straight as I cant see any light under it when I roll it.
The problem may be that drill rod is not round. It is made by a
centerless grinding system and is often quite 'lobed' You can see this
if you start to lap the outside of a piece- it will first show shiny
makes in 3 or 4 places as you start to make it round. Sometimes you can
measure the out of round by mikeing it at several points around it.
Rollies dad always used a rod from an old car front end strut- Rollie
ran a garage and had lots of old struts to hand out to the guys in the
club. I still have one or two in my 'stock room', or scrap pile.