Re: Max feedrate of ball screws?

--- In CAD_CAM_EDM_DRO@y..., "dgmachinist" <scsm@m...> wrote:

>
> <snip>
>
> > My scope is if you dont' need it there is no benefit to have it.
> > Good luck..
>
>
> That's just the thing... I need at LEAST 300 IPM. I intend

on

> doing some serious woodworking, and the speeds required for good
> tooling life are kinda up there, so in the long run, whatever the
> cost is, it might well be worth it...
>
> Seth

If I understood right this is a 0.625 Dia. 60 inch long ballscrew
probably 0.2 pitch.
It would be running at 1500 Rpm at 300 Ipm.
This dose seam marginal to me but may work as long as the weight of
the Table is light and the cutting force small.
There are several posible ways to improve this.
1) bigger dia. screw is more stable at this length.
2) larger pitch on ballscrew to reduce Rpm needed
geared back by pulleys timming belt ratios.
Either or both of these sugestions will be far easier to implement
and much cheaper then the rotating Nut design.
Another interesting observation about the larger pitch ballscrew
compared to a acme screw concerning backlash.
Part of the reason a ballscrew has less backlash is its greater
acuracy but also a ballscrew has more pitch so the ramp angle is
less shallow wich contributes a great deal to this effect.

I am also wondering what the rest of your system is made of
Motors, Drivers, Powersupply and Software.
Multy step drivers capable of reaching the performance you wish?

The goal of a good machine is in the proper balance of the
components used.
Can't build a race car with a pinto engine no mater how good the
frame is designed.

Good Luck