Hey guys, in my experience In order to print using 2extruders it is imperative that both nozzles be as close as possible to thesame height above the bed.

Here is one way to get the 2 nozzles accurately adjustedto the same height on the Flashforge Dreamer:

1. Unload both extruders
2. Make sure the tips of the nozzles are 100%clean. Any small amount of plastic on the tips will spoil the alignment.
3. Place a sheet of 20# copy paper on the bed andrun through the bed height adjustment procedure on the touch screen. Determinewhich extruder is the highest (farthest from the bed) one. By sliding the paperback and forth it is easy to tell which one is higher. This is the one thatwill be adjusted, leave the other alone.
4. Leave the extruder in the X-Y position at the endof the procedure. Run the bed down (not left or right) some with the touchscreento give some work room.
5. Turn off the machine
6. Disassemble the extruder according to theFlashforge video: https://www.youtube.com/watch?v=9BiU9qBgzEU
7. Now re bolt the aluminum bar to the carriage withoutthe steppers motors or fans but with the nozzles in place. Now raise the bedmanually by pushing up on the bottom until the bed is just short of the lowernozzle. There is no harm in moving the bed manually if done slowly, this iswhat is instructed to do in the unpacking instructions for the machine.

8. Place the paper under the nozzles again andreach in to the back of the case and turn the lead screw by hand until the paperis just dragging a little on the lower nozzle. It doesn’t matter how much thedrag is as long as you shoot for the same amount for each time. Loosen the setscrew on the back of the aluminum bar for the too high nozzle. Now push down onthe nozzle where it appears poking out of the top of the aluminum bar until thedrag on the paper feels the same as the other extruder. It doesn’t take a lotof force, just a very gentle pressure. This is best a 2 person operation, 1 toapply the light pressure and slide the paper back and forth and another totighten the setscrew.
9. Now assemble the extruder right on the machine,no need to remove the aluminum bar again which might change the alignment.
10. Now redo the z height procedure from thetouchscreen using the paper again. If done properly you’ll be able to tell thepaper is dragging the same on both nozzles.

In another thread there is procedure for Creator pro tojust push the nozzles all the way up against the aluminum bar but although itwas said there is no problem, on my Dreamer the bed was already close to thelimit going up, I.E. I could not unscrew the bottom thumb screws much morewithout running out thread on the screw. Raising the nozzles that much more Ithink would put them out of adjustment range. There is no way in the softwarethat I could find to adjust the Z height like I have had on other machines. Alsoit did IIRC look like on the extruders it might cause a problem to push themall the way up, can’t exactly recall since it’s been awhile since dong this.Seems I was concerned the top might hit the plastic piece at the bottom of thestepper where the filament exits but that might not be the case.

Anyway hope this helps some to get a good alignment. Itdoes take some time but the results are worth it.