faster steppers was Re: Going home

Ian,

The 297/298 chip combo can handle 40V max! Get nearer to it, but
NEVER exceed it! The 298 WILL fry!

Any way, a 24V xfrmr will be about 34vdc when rectified and filtered.
This is the first step to more speed (assuming you NEED the 1mm lead
on the screw).

Hope this helps.

Ballendo

--- In CAD_CAM_EDM_DRO@y..., "Ian Wright" <Ian@i...> wrote:
> Thanks everyone,
>
> Even if there are varying views in positioning of the home switch
(as I
> really expected), I (and hopefully others) now have some very useful
> information on setting tool lengths etc. I quite like Smoke's idea
of having
> a moving home switch but quite how I could implement that I'm not
sure -
> I'll go and find my thinking cap!
>
> Jon, the motor driver are fairly basic L278/279 combinations with
current
> setback and running in half step mode. The motors are surplus and,
as near
> as I can tell they are about 5volt, 1.5 amp. At the moment it seems
that the
> best speed I can get out of them without losing steps is 210 r.p.m.
In my
> case this is taken through a 3:1 reduction to a 1mm pitch leadscrew
which
> therefore gives me 70mm / min or 2.75" / min! Not particularly fast
and
> that's on a G0 command. Speed doesn't really worry me too much as
the parts
> I will be working on are unlikely to exceed an inch or so in size
but a bit
> more on the rapid would be nice. Maybe there's something I'm
overlooking
> and, if I knew where to look, I could change something to get more
speed but
> I don't know where to look. I don't think it is the motors
themselves as I
> have three different types which all behave similarly so that only
leaves
> the drivers and the computer. Any thoughts?