Upgrade 4 to 6?

I have a 4 and am having horrible problems with the z axis binding. I see that the taz 6 has a radically different setup for the z ends and x carriage. If I print new z tops and bottoms and x ends can I use the rest of my current parts (screws, rods, nozzle, etc) to upgrade my printer?

Yes, though you would need the larger 12mm rods and bearings for the X axis. You can get most if not all of what you need right here: https://itworks3d.com/product-category/parts/taz-6-parts/

You will also need to upgrade to a hexagon hotend and implement the auto leveling setup, because the 6 parts do not have a manual Z height adjustment target. A 6 style bed is $20, a hexagon kit is around $70ish. the corner bits for auto leveling and the harness are probably going to be another $30-$40 or so.

You may also want to look at the Openbuilds X, Y and Z axis projects:

All that being said, you really need to track down and understand what the Z binding issue you are running into is before you attempt an upgrade that may compound that issue. To eliminate that, try the following first

  1. With a set of Verneir calipers, Make sure the distance from the bottom of the X axis end leadscrew nut to the top of the lower leadscrew bearing is the exact same on both sides.
  2. Look at the top leadscrew bearing. is the top of the leadscrew up the center shaft all the way, and the same height both sides?
  3. check the bottom Z motor mounts. Are they both down on the leadscrews all the way so there is no leadscrew play?
  4. watch the z motor couplings for a couple of layers. Do either of them look like they are compressing on one side? Are there any breaks
  5. does each leadscrew coupling have all 4 setscrews, are they down and tight and on the motor and leadscrew shaft flat spaces for at least one setscrew per side? These can easily fall out and cause binding.
  6. If none of that was it, check the frame front and back with a 90 degree square
  7. if it still has issues, unbolt the X axis bearing rod setscrews on the idler side, then run the axis up and down the Z axis agin. Move it back to the middle of the axis, then retighten the screws. This will eliminate either pinching or over bowing.
    8 if it still is binding, try loosening the bolts holding the Z motor in place on the side it is binding and see if that has any effect.

You also want to put white lithium grease on your Z axis leadscrews if there isn’t any already.