Quote Originally Posted by irving2008 View Post
Cret,

Can you outline what was involved in fitting the DRO... or what was taken apart to fit it? I dont know the C3 but I have a similar movement in my ancient lathes and this is simply wear on the nut. What I did find was stripping them down and rebuilding them had a big effect until I discovered that the nut wears differentially and was reversible... accidentally refitting it back to front increased the backlash by 2mm!

Sorry for the slow reply!

I've found the source of the problem and sorted it (at least for now).

It wasn't anything to do with the nut, but related to a collar on the cross slide screw. I forget the name of the part but there's a fitting that goes on the end of the cross slide which keeps the screw locked in place.
Between the new screw and new piece to hold it on (which has a recess that the screw collar goes into) there was over 40thou of a gap which meant you could just pull the slide in & out by this amount. In comparison the original parts had approx 11thou of movement, which wasn't too bad.

I'm disappointed that an 'upgrade' kit made by Sieg for this very mchine would make it worse. I know you can work around backlash on a manual machine but ultimately you shouldn't have new parts from the same people making it a more sloppy machine! Eventually I want to convert to CNC and things like this are a backward step.

I emailed Sieg & got no reply, although I believe they forwarded the message to Arc Euro. They replied to me but they seem to have misinterpreted my gripe into a complaint that the kit should make the machine more accurate. That's not the case, as I've just tried to convey that I don't think it's acceptable that a kit to improve the use of the machine should introduce such a large amount of slop.

I've not got round to replying to them again yet. They did offer a refund if I'm not happy but that's never been my intention. I think they have indeed made an effort to answer my questions but not quite from the right perspective.

Anyway, I've managed to make a plastic shim which fitted perfectly so it solves the problem for now, but obviously that will wear.....

If I get updates on the stance on this I'll pass the info on. My opinion (as a relatively inexperienced machinist) is that it's a sub standard product to have such a poor fit over the original parts even though I like it a lot. Others may well disagree with that.

Cheers
Jim