Re: Rolled vs. Ground ballscrews or other screws!

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<dave_mucha@y...> wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Lance Hopper"
> <snaggletto@c...> wrote:
> > I've run a Bridgeport with ballscrews for a couple years. It was

a

> > beautiful experience in all situations. Climb milling is

possible

> > with smaller cutters and lighter cuts, but any backlash or slop

will

> > be violently taken up if the cutter digs in. Save climb milling

with

> > 2" face mills and heavier cuts for the machining centers. I

don't

> > doubt that anything is impossible, but to throw the table off of

the

> > machine means that the operator is a dumba** and has no sense
> > or 'feel' for how to machine.
> >
>
> I figure it this way, he has been a repairman for over 20 years in

the

> phila area for Bridgeport, so has seen more machines and been in

more

> shops than most tool salesmen.
>
> 2 over that time is not too bad as I have personally met more than 2
> dumba**'s in shops running machines myself.
>
> But as we know a ball screw nut will run it self the length of the
> screw if the screw is standing vertical. an ACME won't do that.

the

> ball screw also does not have the same TPI so it offers MUCH less
> resistance when smacked.
>
> Dave

Dave,
I don't disagree, and my post wasn't aimed at you personally, or
saying that the repairman was a liar. Ballscrews do have much less
resistance, and thus very efficient with little backlash, that's why
they are used. As you said yourself, in a period of 20+ years, the
repairman has seen it happen twice. This is the exception rather
than the norm. I would bet that if we had the details of 'how' it
happened on those 2 occasions, we would see that the machine operator
was doing something inappropriate for the job/machine. My point,
ballscrews on a manual machine is not a bad thing.