Banding and other issues

I have had my SD2 for a couple months now. I have been following this forum, the google group, and read everything I can find about this machine. It is my belief that a poor quality z-threaded rod is responsible for most, if not all, of the banding issues I and others are experiencing. Almost all of the pictures I have seen of SD produced parts have significant banding. Even the parts made by SD!

It is a shame that SD is allowing 1 poor part and some less than perfect QA to severely limit the quality this machine is capable of.

My machine had a base that was not perpendicular to the Z axis, so the motor and shaft were pointed several degrees off to the side and front. This puts a lot of lateral pressure on the z-nut and build platform. The z-threaded road had about 5mm run-out at the tip. After trying unsuccessfully to get support to send me another, I figured I had nothing to lose and straightened the threaded rod by hand, and shimmed the motor level. This almost fixed it entirely. It's not perfect, but I am morally opposed to paying for a replacement part for something that was defective to begin with.

List of QA/assembly issues:

• Bent z-axis thread rod

• Base of machine not perpendicular to z-axis resulting in mis-aligned motor and threaded rod.

• Bushings for the y-axis "jack-shaft" (intermediate shaft, whatever you want to call it) were installed so far off-angle that they exceeded the "self-aligning" abilities of the self-aligning bushings, putting lots of extra friction in the y-axis stage.

• Poorly tensioned and aligned y-axis belts and shafts

• SD printed parts were all exceedingly poor quality. My own printed parts are MUCH nicer. You would expect the companies

• own parts to be as good or better than what the customers could produce.

• X-axis rod ends printed parts, nearly all screw holes were stripped.

• Y-axis printed pulley bracket misaligned, resulting in pulley always pulling to one side and causing additional drag

• Corrupted bootloader, had to "burn" a new bootloader to load latest firmware

• Ridiculously loud extruder fan

Items they really "should" have:

• Had to solder in headers for PWM fan, not technically a problem, but c'mon, what's it cost, 3 cents? Should come with FET and fan already installed.

• Kapton bed is not that cool, boro glass bed is much better.

SD should improve the QA on the threaded rods, provide replacements to anyone with banding issues, along with instructions on how to replace it, and level the motor.

Before and after applying this "fix"