N2 - Z-axis movement is ONLY down

[Jerry Jackson]

After working through several minor and annoying problems I was thinking I'm ready for a 5 hour long print. Initial problems were:

• random nozzle clogging - thought it was fixed with upgrade to V2 hot end and latest firmware.
• bed nowhere even close to being level or flat. A good bit of time after tweaking the bolts and set screws I had it flat enough and Z zero plenty close enough for decent laydown of the first layer.
• X-axis movement vibrations - apparently the result of mechanical binding which was relieved by loosening all 4 of the X/Y rod retaining screws (which were all rather tight) and leaving them all just barely touching the rods. It was easy to feel the binding moving the carriage along X and easy to feel freedom of movement after loosening the bolts.

NOW I'm ready to print! (or so I thought).

4 hours into my 5 hour print today I checked on the print progress and was surprised/disappointed to find that the last 10 or so layers missing and a clogged nozzle along with the extruder gear chewing away at the non-feeding filament.

I figured.... probably not a big deal yet - after I cleared the build plate off (right where it was when I stopped the job), then unloaded the filament, heated it up an extra 20C then loaded filament and had nice extrusion which remained nice after reducing the temperature back to the happy place for this particular filament.

Now we enter the twilight zone.....

Hit print and watched patiently as the bed then hot end came up to temp - and then the X/Y homing and then the Z homing - where I was more than a little surprised to see the platform moving DOWN away from the Z limit switch instead of UP.  I should add that the Z steppers sounded a lot noisier than usual.

I killed the power via switch on the back and waited for everything to finish shutting down.

Then I tried to jog the Z up toward the limit switch - but it goes down instead of up. Down goes down as it should - and - up goes down as it should not.

Any ideas on what I can try before I rip into it and start checking all the wiring, stepper coils, cooling fans, etc ??

[Werner Zettlinger]

Someone else had this problem

http://forum.raise3d.com/viewtopic.php?f=2&t=227&p=2017&hilit=only+goes+down#p2017

It ended up being the stepper driver.

My advice is to start a support ticket they will try and help you fix it or replace the stepper driver

ps. For Raise3D it is easier to post in their forum than on Google Groups which is not always accessible since the Great Firewall blocks it

[Jerry Jackson]

Z axis stepper driver was bad. They're sending me a replacement.