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Step by step, lots of pics, few words. Click on the pictures to enlarge them.

“Snugged up” for 5/16″ bolts or M8 ≈ 5.5 NM


!XYZ Part with hardware

  • For each XYZ part, using 4x 1.25″ (M8 x 30) bolts, lock nuts and 608 bearings assemble as shown:

!XYZ Parts assembled

  • Make sure the bolt heads face as shown for Z-Axis clearance.

  • These bolts can get snugged up and should not be touched again.

  • YES, the outer nuts are a pain to tighten if you are using 5/16″ hardware (but easy for 8mm). Pre-thread the nylocks to loosen them up a bit then just wedge a small flathead screwdriver in there and tighten it. No big deal. This is not going to change, we have metric and imperial hardware to account for. I do not want to maintain two sets of every part for something that gets done one time.


!XY part with hardware

  • XY part, 4 1.25″ bolts (M8 x 30), nuts, and bearings.

!XY part assembled

  • Assemble these as shown with the heads out.

  • Do it for both XY parts.

  • These bolts can get snugged up and should not be touched again.

These bolts can get snugged up and should not be touched again.

!XY parts 1.5bolts

Using the 1.5″ (M8 x x40) bolts, nuts and bearings assemble these into the end of the XY parts that only have 1 hole.

!XY parts bolts installed

  • As shown on the picture on the right the heads should be put in in opposite directions (purely cosmetic), when assembling later these heads should face up.
  • Tension Bolts A – Control X and Y Rail tension, slight effect on the squareness. More on this at the end.
  • These should be left extremely loose, just tight enough to engage the nylock on the lock nuts.

Tension Bolt “B”

This step uses the XY, XYZ, Lock Nut, 5″ (M8 x 130) bolt, 2 bearing, both gantry spacers, and a nut.

!XY XYZ and hardware

The 5″ (M8 X 130) bolt goes through the XYZ plate.

!5" bolt goes through the XYZ plate

Next is a gantry spacer.

!Add Gantry Spacer

Add the XY piece, align it with the hole on the side of the XYZ piece.

!Add The XY piece

Insert a bearing into the XY piece.

!Insert bearing into XY piece

The second XY piece is added to the stack, again lining up the side hole.

!Second XY piece is added

The second bearing is then added.

!Second bearing is added

Add the second Gantry spacer.

!Add the second gantry spacer

The second XYZ piece is next, upside down as compared to the first. Like face to like face.

!Second XYZ is next

Followed by the lock nut.

The lock nut should be kept loose, just engage the nylon.

This 5″ (130mm) bolt is Tension bolt B.

Add in the brass T8 nut and secure with 1 or more M3x10 screw

!Add in the brass T8 nut

These screws only prevent the nut from turning no need to over tighten or fill all four holes.

!T8 nut installed

It is best to actually leave these a little loose to allow the nut to have better alignment with the screw. Seat them all the way and back off a half turn.

Tension Bolts C(x4)

!Tension Bolts C

Use the 4, 2.5″ (M8 x 65) bolts, bearings and lock nuts.

!Bolts C installed

These are Tension Bolts C.

These should be left extremely loose, just slightly touching the plastic.


Now that the assembly is complete, this is the best time to double check to make sure the rails are perpendicular.


An inexpensive square works just fine. Both of the ones pictured were about $5.

Insert all 4 rails into the assembly (X, Y, and The Z assembly).

!Insert all 4 rails

  • The least amount of tension on the rails is best.
  • At this point, with all the tension bolts loose the rails they should actually be a snug fit, if they are not post some pictures in the forums so we can help.
  • Tension bolts “C” should have the locknuts and the bolt heads tightened so they are just touching the plastic. Equal light tension keeps the Z axis perpendicular to the work surface and locks the assembly together.

!Check squareness

  • Use a square to see if your XY rails are, perpendicular.
  • You can tension bolts “A” and “B” to adjust the rail angle. It is best to adjust by loosening them. If they are already loose tightening them slightly moves the rail away from the tension bolt.
  • I’m sorry there is no magic bullet for this part. For most people this should go together square as is, but if you are having issues you might just want to run it as is for a while and then try again after it has been broken in a bit. You cannot really do this in the rollers so any adjustments should be in loose rollers or apart to this stage.
  • This part can be tricky for some, take your time. Small adjustments.


  • Lube the lead screw.

  • If you are new to all of this, don’t worry about perfect here yet. Most people never even know or care how perfectly square there machine is. Carving a name into a piece of wood no one would notice if it is a 32nd of a degree off square. Have some fun learn some things, you can always come back to this later.

  • Using the blue square picture as reference, assuming Tension bolts A and B are all the way loose. Tightening B (the long one) would make the angle smaller as shown on the blue square. If instead you tightened both A bolts a bit the angle should open up.

  • If you run into Z axis perpendicularity issues later on it usually means your C tension bolts are not equal. Tighter on top pushes the rails away from the bolt, as well as the bottoms. A square from the work surface to the Z rails can test this after full assembly.

Done, looks cool right?!

Main assembly page