MiltRap Y-Axis Brace Front Bracket

thingiverse

This part replaces the front and back frame stiffeners included in the Z Brace mod. A thicker front bracket and a threaded rod provide better frame stiffness by adding support from front to back in the middle of thin front and back frame panels. The printed part, Front YBrace Bracket, has four holes for screws that secure it to the panel with 2.5mm taps or other preferred screws. It also features an indent for a threaded rod to brace the Y axis directly under the Y Belt and a vertical extension to add support. Parts list: 1x 16" (or longer) 3/8 threaded rod 2x 3/8 nuts 2x 3/8 ID washers, with narrow outer diameters to fit between frame wire harness cutouts and Y axis stepper motor L brackets To install: Install a nut and then a washer on one end of the threaded rod about four inches down. Install the second washer and the other nut at the end of the rod. Mount the printed Front YBrace Bracket on the front of your i3, replacing the Z Brace part that goes there. A 3/8" threaded rod fits through the cutout for the wire harness on the back frame panel that mounts the motor and rails. Move the wires and put the threaded rod through that cutout until it rests in the small pocket in the Front YBrace Bracket. It should be under the belt pulley slightly offset. Check that the rod is not touching the Y Belt or the Y Carriage Belt Bracket. A few millimeters clearance is fine; nothing should move except the belt in a predictable path. Now, tighten the inside nut outward against the back frame panel carefully. Standard 3/8 nuts may slightly clip the stepper motor M3 cap screws, but can be tightened by sliding the assembly away from the stepper motor slightly. Turn the inside nut so it moves outward and pushes on the back frame panel until you have braced your front and back plates. Do not over tighten it and bend your panels outward; just turn it enough to brace the panels from moving inward. Tighten the remaining outside nut to hold it all in place. This provides a direct compression resistance member very close to the motor and pulley, almost directly under the belt (offset about 2mm but offset closer to the center of the frame due to the belt being slightly offset). Edited: Replaced STL with one in proper printing position, old version was laying flat in a poor position for printing. Print Settings: Printer: Monoprice Makerselect i3 Rafts: Doesn't Matter Supports: Doesn't Matter Resolution: I use 0.18 layer; you can use that or whatever suits you. Infill: I use 50%, use that or your structural part preference. Notes: Internal slot is modeled to 1.7mm, in case anyone was wondering. You don't need the screws to hold it in place once the Y axis brace rod is installed; it holds in place, but they look nice. I consider the parts and project done for now, marked as a WIP though as it certainly could be improved. You really don't need the printed part except a little foot for the rod; someone could just do that and print a little round cap for it as a minimalist version.