tealvince wrote:

Another idea:  Since the banding is periodic, why not just cancel it out in the gcode?  I'd like to see this as a feature in Slic3r, but in the meantime here is a simple command line perl script that should do the trick once you experiment to find the proper displacement and phase values to cancel out:

#!/usr/bin/perl

if ($#ARGV lt 1) {
print "$#ARGV USAGE: wiggle <infile> <outfile> <max displacement (0-1.0)> <phase (0-1.0)> [<peak-to-peak spacing (mm)>]\n";
        exit;
}

$pi = 3.14159;
$displacement = 0.5;
$phase = 0.0;
$spacing = 25.4 / 18;

if ($ARGV[2] > 0 && $ARGV[2] <= 1.0) {
        $displacement = $ARGV[2];
}
if ($ARGV[3] > 0 && $ARGV[3] <= 1.0) {
        $phase = $ARGV[3];
}
if ($ARGV[4] > 0) {
        $spacing = $ARGV[4];
}

open(INFILE, "<$ARGV[0]") || exit;
open(OUTFILE, ">$ARGV[1]") || exit;

while(<INFILE>) {
        if (m/(G1 Z)(\d+[.]\d*)(.*)$/) {
                $val = $2 + $displacement * 0.1 * sin(2.0 * $pi * ($phase + $2 / $spacing));
                $_ = "$1$val$3\n";
        }
        print OUTFILE $_;
}

close(INFILE);
close(OUTFILE);

Very nice! If this works we will put it on Solidoodle Github, or package it with out software.

While we wont give away most of our research in to the topic, banding can be caused by interactions between the rod itself, the rods threads, the rods internal boring, the Z-motor, the rods connection to the Z-motor, and the Z-motors connection to the Solidoodle. The problem doesn't manifest from the same circumstances Solidoodle to Solidoodle. We've tried a few things with good results, but the issue (as always) is cost. There are definite tried and true solutions to this issue, but they are typically expensive and would take us away from our mission to provide the printer at a reasonable figure for consumers.

That said, given sufficient demand we could consider putting some more expensive solutions in our store as "upgrade" options. We've shied away from this since we do not want to give the impression that you need to get an upgrade to make the Solidoodle work correctly in the first place. What we'd really like is a solution that makes the $499 base model work without banding each and every time - we don't want to have to increase the price. That said, who knows - if there is sufficient demand we'd be open to offering wobble reducing solutions in the store.

Regards,
John

Curious, you say "While we wont give away most of our research into the topic" you will also use this guys work to your advantage and package it out with your software.

That kinda sucks.....

The big warehouses don't have it.

This should surely be mentioned in the wiki .....

The rod is not metric. 5/16 18tpi.

And where do I get ONE non-metric nut?

7mm.

There's your problem!

What thread is the nut?

7mm. Should fit on the rod.

Any news yet?

Can the z-axis design be improved upon?  Certainly, but this type of artifacting seems completely common for other printers in this class, so I don't think SD necessarily needs to do anything to their hardware.  Besides, with the latest firmware you can simply calibrate your printer to eliminate the banding, so IMHO this is a solved issue:

http://www.soliwiki.com/Calibration_of_the_Z_wobble