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XY-Carriage Alignment

Correct alignment of the X/Y carriage is the most tricky part of the Vertex assembly. If you fail achieving a perfect alignment of the axis you'll end up with a lot of shifting and your printer will be useless.


If you set the distance between the two clamps exactly as written in the manual, chances are that the movement is only OK in the center and difficult near the ends of the axis (test the movement without the belts installed : there shouldn't be almost any friction i.e. the carriage must move freely from end to end when tilting the printer).
If not move your axis towards the ends and check if the outer rods tend to bend inwards or outwards. Inwards means the clamps are too close and outwards that they are too far from each other. You'll probably have to modify (more often enlarge) the distance between the clamps by a few tenth of a mm to get the head moving smoothly along the full axis.
This is really, really important for a proper functioning printer in the end!

Alignment procedure

  1. Remove all the belts and release all the pulleys
  2. The printer head should now move without any noticeable resistance. If you tilt the printer 45 degrees, the print head should freely slide from side to side. Many times the printer head moves freely in the center, but meets resistance in the ends of the travel direction. Normally the clamps needs to be adjusted further away from the center. Try giving it a light knock with a hammer, and then try sliding again. Continue until a free movement is gained all the way. (don't forget to insert a piece of plastic or wood between the clamp and the hammer!). It is all about hitting the right tolerance, so the free movement is obtained. To know if you got it right, do the following : put the print head in the center of the printer ; remove the end cap of one of the lateral axis and slide the axis to release it from the ball bearing on the opposite side - try sliding the rod back in the bearing - if its not dead in the center of the bearing check where the rod is hitting the bearing : on the outer border of the hole --> the clamps are too far away from each other ; on the inner border means the clamps are too close from each other.

Out of alignment.jpg

  1. From here you'll align the belts and pulleys working one side at a time. Put one belt back in place but don't insert it into the belt tensioner
  2. Place 2 spacers between the axis and one of the side rods (each one near the end). The purpose is to get the rods // (you can use the printed ones you can find below or - if you can't print - use anything allowing you to set the same distance like 2 blocks of wood or 2 identical open-end wrenches).
  3. Insert the belt in the tensioner but without tightening it
  4. Align the pulleys to have the belt touching the inner edge. The belts must run straight and not from one side to the other. Be careful with the pulleys hosting two belts. They must not overlap (you'll probably need to tilt the motor a bit to achieve this)
  5. Tighten the pulleys and then the belt tensioner (but not too much, your belt is not a piano string). Check if the belt is running straight and realign if necessary
  6. Repeat steps 4,5,6,7 for all remaining sides

Clamp hammering.jpg
Hitting Clamp to adjust clearance.

Belt t10.jpg
Correct tension of the belt.

Makeshift alignment tools
Alternat align.jpg Align.jpg

XY-Carriage Alignment Helper (by H60)

A simple tool to help align the xy carriage rods of the Vertex K8400.
The rods for the XY carriage should be as parallel as possible.
Print 2 of these and clamp them onto the rods. This will align/tune the rods to become parallel.
Then tighten the pulleys and belts (don't tighten them too much, just the minimum to hold them in place).

Vertex xycarriage cal helper.jpgVertex xycarriage cal help1.jpgVertex xycarriage cal help2.jpg

Link to the object on Thingiverse

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