Re: [CAD_CAM_EDM_DRO] Re: DIY Router Design questions ?

Dean:

Wow, your close, its actually .029 per full step. I use a microstep of 10:1
for .0029/inch. I find this resolution is fine for almost anything I do. I
do a lot of photo engraving , signs and decorative woodwork with no real
resolution problems. I have found that the CAM software output seems to only
give .002 or so resolution for most things depending on how its set up. Wire
rope is fine for my purpose, is very cheap, requires no real critical
alignment so at this point I swear by it. As you can see I drive the drive
pulley right off the stepper motor itself. Since the stepper is a modified
SloSyn AC motor, it is quite powerful and can drive my X axis at up to 10"
per second, though I could never cut at that speed, I have snapped bits by
trying. I would recommend that anyone trying to duplicate my efforts, put a
reducer on the stepper and go at maybe 3:1 to the pulley for a more accurate
system. My system is handy because if you kill the motor enable signal, you
can just grab the gantry and pull it toward you and place the toolbit where
you want it to be, then hit enable and it locks in place. Like I've always
claimed, your system should reflect your needs. The largest mistake I see
people make is trying to design to standars like 30000 pulses per inch. You
can't get that kind of resolution anyway, so why bother. (my appologies to
the metalworkers in the crowd who CAN get that kind of resolution and do
need it). For a home hobby type system, stay away from any more than 5000
pulses per inch and it makes it much cheaper. My Z axis is 16480 steps per
inch, but I just happened to find a acme screw with that pitch, otherwise I
would prefer less for greater speed, but these SloSyns are fairly fast, so
even at 16480 I get pretty good Z speed and can crush just about anything
due to the ratios.

Art

----- Original Message -----
From: <deanc500@...>
To: <CAD_CAM_EDM_DRO@yahoogroups.com>
Sent: Sunday, August 12, 2001 9:37 AM
Subject: [CAD_CAM_EDM_DRO] Re: DIY Router Design questions ?


> Art, is your system is direct drive off the motor? If it is, I make
> the resolution at around .025"/step (full step) looking at the photo.
> How do you like it? Seems to me cable drive is where its at for a
> cheap and simple machine.
>
> -no expensive lead screws and anti backlash nuts
> -no critical alinment parallel to the axis
> -no flex couplers to the motor
> -no thrust bearings at the far end of the screw
>
> -racks are not as cheap as cable
> -racks still need to be accuratly mounted
> -the rack itself may or may not come drlled and tapped for mounting,
> you must do that or weld it on
>
> Cable couldn't be simpler if the performance is there.
> Dean
>
>
>
>
> --- In CAD_CAM_EDM_DRO@y..., "Art Fenerty" <fenerty@h...> wrote:
> > Rab:
> >
> > Just uploaded 2 better pictures showing the servo motor mounted
> beside the
> > router( laminate trimmer) that I use the most. You can just see the
> wire
> > rope on a boat pulley on the Y axis if you look carefully.
> > Art
>
>
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