GinaRep Concorde 3D Printer

[Gina]

https://stargazerslounge.com/uploads/monthly_2019_11/1041117794_Printer01.thumb.JPG.140044ec736e44649f2a1ba5c126ec17.JPG

[Gina]

The box was built from high quality hardwood plywood panels 18mm x 610mm x 610mm (2ft x 2ft). The size was derived from a previous printer build which used a casing made from 500mm square acrylic panels with 3D printed corners connecting the panels, except for the base and back which were plywood, so I searched for ready cut pieces of plywood this size or larger and came up with the 2ft square sheets (a bit bigger than I really wanted but not by much).

This CAD model gives an idea of the arrangement of some of the parts within the box as I envisaged it before starting the build.  Some aspects were changed as the build went along to fix problems and improve the functioning.  X and Y rails were and still are aluminium extrusion "V" rail with the carriages running on them with matching ball bearing wheels. The Z axis also used "V" rail vertical pieces with 3D printed Z carriages running on them and supporting the print bed. The Z carriages held the bed level with any remaining deviation from truly level being compensated for in the firmware using Z probing immediately prior to printing. I'll say more about the "V" rail system later.

This CAD model with the box removed shows the first design with the Z stepper motors mounted under the base of the box.  This arrangement was changed later with the Z motors mounted inside the box and a much more rigid Z carriage and rail system.  Also, the original 500mm square bed was changed to 400mm as 500mm square proved impractical.

[Gina]

All the running rails are V-Slot aluminium extrusion and sold by ooznest (https://ooznest.co.uk/product/v-slot-linear-rail-20x20mm-cut-to-size/).  The X ad Y rails are 20mm x 20mm cross-section and the Z uses a much bigger extrusion called C-Beam.  https://ooznest.co.uk/product/c-beam-linear-rail-cut-to-size/

20mm x 20mm extrusion showing a standard size wheel.  I use the "Mini Wheels" which are a bit smaller.

The final Z running arrangement used a variant of this, with a longer (higher) gantry plate and motor drive at the top with timing belt drive. (Click image to enlarge).

This photo shows the final Z drive.  A standard size (40mm) NEMA17 was plenty powerful enough