Letter sized Press

Not a direct remix of Martin Schneider original, but heavily inspired on it (only today I realized you are working on an improved design, looks great!). Visit the original thing for additional tips on print making.

https://www.thingiverse.com/thing:2841592

Also, I used the rushman´s Customizable rack and pinion library.

https://www.thingiverse.com/thing:1227374

Re designed from scratch in OpenSCAD, with the objective to be able to use letter size (8.5x11") paper. Scad file included, so design can be adapted to your specific needs (use of metric bolts&nuts, for example) as required.

Minimum cost was not a design driver, but the total cost should be around US$60 (a little more if you don´t have materials at hand... you cannot buy 1 brass insert, you have to buy them by the hundreds!).

I cannot print the complete rolls in my printer (too tall), so I cut them in halves. Print two halves and join with the half_rolls _connector and super glue. Glue two shaft_cube the non geared roll sides, and one shaft_cube and one shaft_cube_with_connector to the geared roll sides. The design has tight tolerances (0.2 mm), you may need to sand the connectors to fit.

The geared roll is the only part not completely designed in OpenScad. If you want to change its design, you will need to add the gears (in "roll_gear.3mf" file). (3Dbuilder can do that).

The lower_block height can be adjusted to raise or lower the cylinder gears, to ensure the bed is perfectly horizontal.

Slightly thinner or thicker wood board can be used. For thinner boards, the "geared rack" height needs to be reduced (edit mesh file, or sand the original one).

Glue the thin metallic plates to the top of both upper_blocks to avoid the eye bolt direct contact to damage the block.

I used brass inserts mainly because I wanted to learn how to use them. Only the M4 inserts for the upper towers are critical (under stress).
The insert diameters I used may not be the best fit for yours (OD is not standard). I recommend to do some testing for the inserts, and optimize the diameter in the script.

I included a removable "extension" to keep the table horizontal when the table end lefts the press (you may or may not need it).

3 perimeters and 30% infill is enough for most of the parts. I used PLA for rigidity (try to use the pro versions that are not brittle, and allow easier sanding for adjustment of pieces).
upper_tower part is under tension and shall be printed with 5 perimeters and >=50% infill. Print it flat to have maximum stress capacity in the Z axis. In my printer, only supports for the inner rails were necessary.

PRINTED PARTS
2 x half_geared_roll
2x half_non_geared_roll
2 x half_rolls _connector
1 x handle_V19
4 x leg_V19
2 x lower_block_V19
2 x lower_tower_V19
2 x pedestal_V19
1 x plate_extension_V19 (optional)
2 x plate_V19
2 x rack (epoxy glue to the wood board)
2 x roll_gear (only if you need to re design geared roll)
1 x shaft_connector_V19
3 x shaft_cube_V19
1 x shaft_cube_with_connector_V19
2 x tip_V19
2 x upper_block_V19
2 x upper_tower_V19

BOM
1 x Aluminum rod 1/2", 170 mm
2 x threaded steel rod 5/16", 270 mm length
2 x eye bolt 1/4", 1 1/2" length
4 x 6805 type bearing (25x37x7 mm).

2 x 1/4" nuts
8 x 5/16" nuts
8 x 5/16" washers
8 x socket head M4 bolts, 8 mm
8 x socket head M3 bolts, 6 mm
8 x M4 brass inserts, 6 mm
8 x M3 brass inserts, 4 mm

1 x wood board 288 x 217 x 11 mm (you can design/print one too, but this size was too big for my printer).
2 x thin metallic plate (12 x 7 mm), (coffee can lid is a good material for this!)