Re: CNC Router belt drive

Hi

Thanks, I now understand the belt drive. But I don't think I fully
understand the stepper motor and servo thing. If the machine is busy
cutting something on x-axis and y is standing still. Does the
electric drivers apply electricity to the y motor to prevent it from
moving? Otherwise the force of the head cutting could make y move. Is
this what they call holding torque or stall torque in the motors
datasheets?

Thanks
Wayne

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "caudlet" <thom@t...> wrote:
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "wgaybba" <wgaybba@y...>
wrote:
> >
> > Hi
> >
> > I'm planning on building a cnc router. Instead of having
expensive
> > screw drives, could I use a timing belt drive for the three axis.
How
> > will this drive compare to a screw? Can a belt drive lock like a
screw?
> >
> > Thanks
> > Wayne
> >
>
> There have been a lot of tables built with belt drives. You have a
> choice of a continuous belt with a drive motor on one end and an
idler
> pulley on the other or an open piece of belt attached at the ends
with
> the motor on the gantry and the belt looped/around (>180 deg warp)
> with idler bearings keeping tension and the wrap (kinda like a 16mm
> projector mechanism (:-))
>
> The belt drive of either style will not "lock" if the motors are not
> under power. This can be an advantage as well as a disadvantage.
For
> static loads (horz) it affords a way for you to manually move the
load
> if it's ever required. If power is applied to the motors (stepper
or
> servo) the drive electronics will "lock" the motor and the load.
>
> leadscrew drives work on short or loaded (verticle) loads. It's not
> unusual to see a screw drive Z and rack & pinion or toothed belt
drive
> X & Y.
>