just built the printer and z axis useless

[NatWilsher]

okay so I built the printer to find out that only way the z axis will work is if I make all the screws on z axis motors and the brass thread thingies all loose. then i'm able to use the z axis. IF I tight a single screw then it will get jammed. apart from returning it and going with a different brand all together cause i'm really annoyed right now any suggestions? this is a genuine question cause im literally exhausted all my own knowledge and googling and youtube and forums. like all I ever see if have you over tightened the screws... I cant even tighten 1 out of 16 screws im talking about without it jamming. to make it worse when I tighten it I swear the screw rod wobbles but I am not totally sure cause its not noticeable when all the screws loose cause the parts are free to move. I am literally about to give up. please help thanks

[William]

Hi, Regarding the problem that the z-axis does not move, you can check the following aspects:
1. You can remove the threaded rod first to see if the motor itself is normal.
If the motor is not working properly, you can exchange other shaft motor wires to the z-axis motor for inspection to determine if the motor wire is damaged and the motor cannot move correctly.
2. If the motor moves normally, you can check if the threaded rod is bent and cannot move, and the bending needs to be replaced;
3. Check if the coupling is installed correctly;
4. Whether the left z-axis and the right z-axis are at the same level;
5. Whether the voltage of the driving board is in the range of 0.8-1.2V;
6. Can loosen the brass nut slightly;
Specifically, you can refer to this:viewtopic.php?f=82&t=60931
I hope this can help you.

[moorebrm]

Z axis problems can be amplified by incorrect X axis locking collar location and belt tightness.
The geeetech manual indicates putting the X rod locking collars on the outside of the Z axis bracket don't do this.

First Put the collars on the inside of the bracket (the Extruder side) - this stops the Z axis rods from being under tension when you tighten the extruder axis belt.

To do the job
1. The rods are too tight in the metal X brackets (due to the Black paint finish) remove the X rods and run a 8mm drill bit through the holes to get a gentle pressure sliding fit on the rods.
2. Refit the rods with the locking collars on the inside of the brackets NOT the outside - do not tighten the collars at this point.
3. Make a thin cardboard, plastic or thin sheet metal height gauge (best) 45 to 50 mm wide that you can use to set the X axis rod height off the z axis stepper motor mount. Rotate the 8mm Z axis screw coupling (by Hand) until the X axis rods are the same distance away from the Z axis motor brackets(common fixed reference point) on both sides of the printer - this should make the X rods at right angles to the Z rods.
4. Push the Collars out against the X/Z black metal bracket then lock up the collars to the X rods.
The Collars are now spacer on the X Rod bracket preventing the tightening of the extruder belt pulling in and distorting the z axis rod alignment.
5. Now tighten the X axis Extruder belt.

Check the machines Z axis performance
Check you don't have run-out on the z axis thread caused by incorrect coupling attachment. refit the coupling to minimize the run-out effect - It is a good idea to leave the brass nut z axis screws loose - I have mine attached with cable tie straps to allow for the small amount of run-nout I have.
If the Z axis is OK reset the X axis level with your reference spacer Home the machine and with a texta/paint pen mark a visual reference line on your Z coupling across to your Z stepper motor bracket on both sides. Always check the X axis level prior to print with the visual reference line.(the steppers get out of sync at times).

Hope this helps - needs to be done anyway to get good reliable prints.
Regards mooreb