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

IMG_20160527_115312~01IMG_20160527_120233 IMG_20160527_115751
  • Using the XYZ part, 4 1.25″ bolts, lock nuts and 608 bearings assemble as shown.
  • Make sure the bolt heads face as shown for Z-Axis clearance.
  • Do this for both parts.
  • These bolts can get snugged up and should not be touched again.


  • XY part, 4 1.25″ bolts, nuts, and bearings.
  • 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.


  • Using the 1.5″ bolts, nuts and bearings assemble these into the end of the XY parts that only have 1 hole and the letter marked on that end.
  • 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.
  • These should be left extremely loose, just tight enough to engage the nylock on the lock nuts.



  • This screw and nuts are only used if you are making a machine using allthread instead of the lead screw. If you are using the T8 lead screw just insert this piece with no hardware.
  • (allthread use only) Use whichever Nut Lock part fits your coupling nut. 11mm or 13mm x .75″ . This is measured by the flat to flat measurement, a .75″ screw and lock nut will also be needed.
  • (allthread use only) Insert the coupling nut make sure it does not protrude from either side.
  • (allthread use only) Snug this screw up it will not be used again.


  • This step uses the XY, XYZ, Lock Nut, 5″ bolt, bearing, and a nut.
  • The 5″ bolt goes through the XYZ plate, then Nut Lock, into the small hole on the XY part trapping a bearing in the gap.
  • The head of the 1.5″ bolt on the XY part should face the XYZ plate.


  • Add the other XY part and trap the next bearing the same as the previous step.


  • Add the Spacer, then the other XYZ plate.


  • Add the lock nut to the bottom of the XYZ plate and 5″ bolt.
  • Tension Bolt B – Controls X and Y Rail tension only.
  • This should be left extremely loose, just tight enough to engage the nylock on the lock nut.


  • Use these 4, 2.5″ bolts, bearings and lock nuts finalize the assembly.
  • Tension Bolts C – Control Z Rail tension, slight effect on the squareness.
  • These should be left extremely loose, just tight enough to engage the nylock on the lock nuts.


  • Only if you are using a T8 lead screw.
  • (T8 only) Add in the brass T8 nut and secure with 1 or more M3x10 screw
  • (T8 only) These screws only prevent the nut from turning no need to over tighten or fill all four holes.


  • 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, If you don’t have one you should have one on hand they tend to come in handy once and awhile with a cnc machine.
  • Both of the ones pictured above were about $5.


  • Insert all 4 rails into the assembly.
  • The least amount of tension on the rails is best. You are aiming for all bearings touching and smooth movement in the following steps. If your bearings aren’t already making contact you might have odd sized conduit, make sure you are using the right size for your parts. C=23.5mm OD, F=25mm OD, J=25.4mmOD.
  • First check that the X and Y rails are equally tensioned in the XY blocks, all the bearings should make contact. If you need to add any tension start with “Tension Bolt A”, at this point it is best to leave “Tension bolt B” loose (it locks the assembly in place as well as rail tension).
  • Second step is to make sure the Z rails have equal tension and all the bearing are making contact. If you need to add any tension use the “Tension bolts C”.
  • Use a square to see if your rails are, well, Square. If they are, give “Tension bolt b” a turn or two, making sure the X and Y rails are still free to move. If your assembly is not square loosen all the tension bolts up and flex it in the direction needed, then tighten the Tension bolts one at a time to see which one is causing the issue. 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 it is much easier to adjust it here, like this, before putting it on the rest of the machine.







-Everything past this point is for the old center assembly-

Middle Assembly

IMG_20150719_141947Tools needed, Phillips screw driver, Needle nose pliers, 2 open ended wrenches


IMG_20150719_122131Middle joiner, 1.25″ bolts, bearings, lock nuts.


Snug not tight.


IMG_20150719_1226271.75″ bolts, lock-nuts, bearings.

IMG_20150719_123013Both Heads Facing up.



IMG_20150719_135301Z Nut lock, .75″ screws, lock nuts.

IMG_20150719_135625The small hole on the z nut holder faces up. Keep these fairly loose until the Z assembly gets put on.


IMG_20150719_135739Middle End, 1.25″ bolts, lock nuts.




IMG_20150719_1422051.5″ bolt, bearing, lock nut.


IMG_20150719_142506The heads should face each other.



Rigid Middle Z, 1.25″ bolts, Bearings, lock nuts. (same for regular middle z)

IMG_20150719_140634Heads should all face in for clearance of the Z axis later.



3″ bolts, bearings.

IMG_20150719_143004Middle end center bolt head facing up.




Add the lock nuts, loose until the other half is fit.





Add the other half, with 3″ bolts, bearings, lock nuts.





Snug up all 4 lock nuts.



IMG_20150719_144149 IMG_20150719_144246

middle middle half middle z middle end