Strangely my Nema23 had ø4mm threaded holes and I thought it appropriate to widen the hole with a ø4.5mm tip and then make a new ø5mm thread. My 2040 profiles had ø5mm holes while the standard is ø4.2mm; so I had to thread them for a M6 bolt (and therefore enlarge the holes in the two side panels).
If your profiles are perfectly standard, thread them for the M5 and there is no need for changes to the other elements.
The M5 L75 threaded bars must be inserted in the components “Y carriage LA”, “Y carriage LB”, “Y carriage RA”, “Y carriage RB”, “X carriage A” and “X carriage B”; in the X panels they must be positioned both above and below. They will be fixed with two-component epoxy glue: for its correct use follow the product instructions; I left them to cure for at least a day.
To give greater rigidity to the 20mm plywood top, I made a 10cm-high grid of panels with a mesh of about 25x25cm; the reinforcements are in plywood to which I previously made the comb joints. I then fixed the pieces with pocket holes.
Assembly is quite simple and presents no particular problems but it is important to check its geometry.
For the X track it is important to check the squaring of the lateral surfaces with the long side of the profiles 2040 and that the external vertical distance of the profiles remains constant in each section.
For the Y tracks I verified the orthogonality of the feet with the base plane and then that the distance between track and floor is always constant. I also verified that the free sections of the two 2040 profiles have the same size.
In the case of small errors, they can be remedied with a little sandpaper or with a little adhesive tape to insert a small thickness. Do not fix yet the rails to the Y basis.
Then proceed with the assembly of the Y carriage, fixing first the components “LA” and “RA” to the track X; then mount wheels, pulleys and spacer. Then proceed with fixing the external panels «LB» and «RB», the motors, the limit switches (2 on the left and 1 on the right for squaring) and the lower parts of the carriages.
I have assembled them separately but not yet fixed. The X carriage is the component with the most pieces. It is advisable to start by mounting the rear part (pieces D, E, motor, pulley, limit switch, etc.) on panel B, then mount the 608ZZ on the top panel C and the two ø8 bars, checking that they are vertical and parallel to each other.
Mount the lower part of the carriage with the 6 wheels, without tightening the screws. Assemble the upper part of the X carriage (panels A, B and C), check the alignment and then mount the 6 wheels; assemble the Z carriage and all its parts and insert it between the two bars. Place the X block on the rail and complete it by hooking the lower part, check that the X and Z carriages slide easily and then tighten the screws.
The piece is finally completed by housing the trapezoidal screw, the motor for the Z axis, the closed belt.
SQUARING OF THE GUIDES — XY PLANE
Fix the left Y guide to the plywood first, to be used as a reference; the track must be fixed as far back as possible, otherwise the work space will stick out from the panel in the front part. Temporarily fix the second Y rail, with the help of the Y carriage, making sure that they are equally distant from the front side of the plane. Measure the squaring of the Y tracks by checking distances and diagonals.
Place the Y carriage on the two tracks and mount the two lower wheel blocks; then insert the GT2 belts giving a slight pretension. The perfect XY orthogonality will be ensured after the first power up, by adjusting the limit switches on the Y carriages.
SQUARING THE CUTTER — Z AXIS
I made the square of the spindle axis with the help of a compass made from a piece of wood about 20cm long; one end is fixed to the spindle while the second is free to rotate and allows you to understand if the axis of the cutter is perpendicular to the plane. If not, it can be adjusted by putting small shims between the Z carriage and the drill bracket.