Prusa i3 Pro B Z axis top brackets with blocks for strengthening rods

thingiverse

The sturdy material used for the frame of my i3 "Pro" B printer appears somewhat fragile, prompting a desire to reinforce it. Since I had two 8mm spindles left over from replacing the Z spindles with trapezoid spindles, I utilized those along with two custom Z-axis top brackets, modified with two blocks each to support these rods. The primary goal of adding these rods is to enable the frame to securely hold heavy items such as filament reels, box feeders, and tool trays without risking breakage. These blocks can be used with or without 608zz (8x22x7) ball bearings. If used without bearings, the bearing insert provides a wide enough diameter for the Z spindles to move freely or indicates that the rods need to be aligned, straightened, or replaced. The photo still shows an earlier version of these brackets, which I later updated by joining the blocks together for increased support along the horizontal rods. The purpose of these brackets is to strengthen the top horizontal bar, not necessarily to incorporate bearings. To address any potential concerns about using bearings, I've included two photos: one showing a G clamp printed without bearings and another with bearings. The G clamp printed without bearings displays a wavy pattern that I mentioned earlier in my response to a comment. The cylinder was printed with bearings and does not exhibit this wavy pattern. However, I do not have identical items printed with and without bearings for direct comparison. Based on my current understanding, I believe that using perfectly straight and aligned spindles is more effective than restricting with wobbly spindles. For practical considerations, I maintain an agnostic position, allowing any design to operate effectively either way. The .scad presets are designed for 5.5mm thick frame material, but the customizer parameters still require some refinement. If you're not ready to print and replace the top brackets, a standalone version of the blocks is available at http://www.thingiverse.com/thing:1789180. Additionally, an early version of a top filament holder that rests on the horizontal rods has been published as http://www.thingiverse.com/thing:1801124. Print Settings: Printer Brand: RepRap Printer: Prusa i3 Pro B cheap China clone Rafts: No Supports: No Resolution: 0.4mm nozzle, 0.3mm/layer Infill: 12% 3dhoneycomb Custom Section: Versions: 2016oct01: Added strengthening rails along the X-axis. Initially intended to serve as rails for guiding displays that are mounted off-center, these rails were later moved to accommodate displays at various positions. To avoid weakening the bracket, I accepted that displaying on this position and height is not recommended. Adjusted screw holes that weren't frame-centered due to introducing a variable "slack" for widening cutouts but neglecting to consider it for hole positions. Widened the diameter of the bearing recess.