Geeetech quality issues and fixes

[Sabbath]

Geeetech quality issues and fixes thread. Hopefully this thread will become useful enought to be stickied.

Please post in this thread if you have either come across a quality issue or have a fix for one. Dont forget to state the model. I'll start;

Prusa i3 M201
-Bent threaded rods: Seems to be common. Make sure you check them before assembly. You can sight along, looking from one end. I rolled one on horizontal piece of glass/mirror and this was easier for me to see the bend. A little flexing by hand improved straightness, to what i think will be ok. I believe others have requested and been given replacements.
-Threaded nuts too tight: I've ran a 8x1.25 tap through the threaded nuts and it removed a little material, so the nuts may be a bit too tight. FWIW I ran a die down the threaded rods and they were fine.
-Power supply failed: This happened on the fourth power up. They originally said they would charge me for a replacement, but then sent a replacement at their expense when I pushed back.
-Filament feed tubing difficult to bottom out in the extruder. Just something to watch. They get caught about 5mm from the base so you think you've got them all the way in, but then have extruder blocking issues.
-Default setting for mixed 96/4 - IMO it should be 50/50 to start. Fixed via the LCD + control
-Default setting for one of the axis (IIRC X) was set to false, so it moves in the reverse direction. Other two axes move correctly and are set to true... Fixed in LCD setup.
From Admin Roxy: "Geeetech does not adjust their stepstick to produce the correct amount of drive current for the stepper motors. Before you do anything else, you may want to check what the reference voltage on the step stick is. (You may want to crank it up some.) "

Prusa i3 M201 Documentation issues
-No suggestion to lubricate all the sliding surfaces (straight and threaded rods)
-No suggestion to run the threaded nuts all the way down the threaded rods to check for binding
-No suggestion to use a level to set frame, X axis rods and heated base as a starting point

[Sabbath]

Another Issue: extruders do not grip the filament well enough, resulting in low density, poor quality print. There is no tension adjustment on the extruders that coming with the M201, so they're not fit for purpose. In the short term I have increased the spring force by forcing the spring coils further apart with a horizontal screw or two, which is a horrible hack, but at least the prints are ok. If i persist with this printer i'll replace with extruder filament drives with something better. The extruder motors seem ok.