The following helpful documentation was written and posted by @steved:
Note: The table cuts and build remain the same for all of the following X-gantry lengths.
EMT TUBE LENGTH for X-gantry – FOR TABLES WITH METAL STRUT SIDES:
Note: Testing has not been performed for use with Optional Urethane Wheels.
If you already have an X-gantry size other than listed, you can cut your strut plates to your choice of size as listed below. You would then need to buy new EMT/tubing and cut to match your choice.
All of the gantry sizes listed below will work with the LR3 adjustable table extenders published on Printables (September 19, 2023).
A. 1425 mm (56.1″) X-gantry length, based on using LR3 non-adjustable table extenders (wood or printed)
B. 1435 mm (56.5″) X-gantry length, based on using LR3 HIDE/PROTECT non-rail side Y AXIS BELTS inside metal strut. This option brings the non-rail side Y Bearing Wheel Bracket closer to the edge of the metal strut to aid in the installation of the mod.
C. 1400 mm (55.1″) X-gantry length, based on using LR3 table extenders (wood or printed, or adjustable). This option works by not installing the two MDF 1/2″-thick spacers before installing the metal strut as per plans. This allows LowRider makers who are building this table and already have a full standard LR3 full sheet build to quickly move to the new table. To use the full area of the design, installing option A or B and the two 1/2″ spacers can be done at a later time.