Bed Issue / Bent threaded rod

When I received my printer I promptly printed the Calibration Box (should have printed yoda apparently)... printed fine with the supplied filament. Attempted to print again using new spool of red/orange PLA and the thing ended in a horrible mess of strands. Cleaned the Bed/head and gave up for the night. Following morning I printed another calibration box by lowering the temp on the head by 10 degrees (seemed like the PLA was oozing out as if it was too hot) - printed fine this time... with a tiny bit of curling near the corners on the bed.

Lowered the bed temp 5 degrees and attempted to print Platform Lifters for the printer (from thingaverse) - everything went well for the first 2.5 hours...then everything started to slide towards the back of the bed (Y axis)... i.e.: the bed wasn't traveling far enough back with each layer it (the material) moved farther and farther towards the rear of printer but appeared to print correctly from a 'slice' perspective. Is this a bed slippage issue and why only later in the print?

Also I noticed that my right threaded rod is bent, and is really noticeable when rotating, could this be causing the issue as the head travels farther up the Z axis?

Any help anybody has would be appreciated...I'm a TOTAL noob to this. Hope the pic is good enough to show what happened.

 

the threaded rod is constrained by the smooth rods. That wobble shouldn't transfer to your print because of this unless its horribly bad ,which your z axis probably wouldn't work correctly anyway.. chances are if your z axis is functioning smoothly.. I wouldn't worry about the threaded rod wobble.. maybe a video to show your threaded rod in action would help..

but i'd look to other things that can cause your problem...like checking your belt tension.. etc....

 

Well haven't looked at the belt so it could be that, checking it now it feels definitely less tight then the X axis belt - I'll have to determine how I tighten that belt as I don't see any place to take up slack... I assume the front (2 screw) end stop plastic piece which appears to be attached to the belt is the adjustment point. I'll check...and I'll see about posting the rod video...if anyone else has suggestions I appreciate any tips / ideas... thanks again.

 

I would say it looks like your y belt is loose. You can unscrew the belt clip on one side and re tighten it a few clicks.

 

Chris, Does your Y belt have a spring tensioner clipped on it? The belt should strum like a very low guitar string. At one point I had the stepper pulley set screws loosen on both the X and Y steppers. It is a bit hard to access the Y set screw because it is under the bed. You may be able to check it by locking the motors in your host program and moving the bed by hand to see if the pulley is working loose like mine did. If you push too hard either the stepper will skip magnetic steps which is good or the belt will skip over the pulley gears, or the pulley will slip.

Come to think about it I also had the set screw come loose on one of the Z steppers as well!

 

SteveC - Nope I haven't seen the spring tensioner on the Y axis. But I'll actual be doing the tightening tomorrow, So I'll properly check then - I haven't seen the full length of the belt yet. Should there already be a spring on the belt?