SmartrapCore Alu X-Carriage with balanced belt tensioning

thingiverse

This is a custom x-carriage designed for the SmartRapCore Alu printer, as well as its wooden counterpart using 8mm rods. The design draws inspiration from mbthor's innovative creation on Thingiverse (http://www.thingiverse.com/mbthor/about), specifically his part number 1566017 (http://www.thingiverse.com/thing:1566017). This x-carriage features a belt retaining mechanism that enables simultaneous tensioning of both belts, effectively addressing the common corexy problem of achieving square objects in both the x and y dimensions. However, it's crucial to note that for this design to work seamlessly, both belts must be precisely the same length and securely clipped into place. This ensures each belt has equal initial tension, with an identical number of teeth engaged on each belt. Two versions of this x-carriage are available: one is designed specifically for printers converted to use f608zz bearings instead of printed pulley sleeves, while the other version fits the original SCALU printer. To assemble the x-carriage, you'll need to add an m4 bolt and an m4 nut or locknut. I used a 60mm m4 bolt with washers at the head end to shorten it slightly. The lock nut should be heat-pressed into the tensioner. It's recommended to cut this bolt so that there are 5mm of space between the tensioner and the carriage initially. Using an excessively long bolt will cause it to protrude, potentially hitting your y-slide and reducing the usable x-width. Don't forget to utilize your original bearings and belts. This design is still in progress, but I'm currently using it with some success despite not having conducted extensive testing yet. The belt clips might withstand normal use, but they could benefit from reinforcement later on. If you're interested in a more refined solution, please check out mbthor's version above, as it appears to be a neater and sleeker option. I'd like to express my gratitude for his valuable advice and assistance. Update 26-08-16: The part cracked around the mounting holes for the inductive sensor, so I've reprinted mine using PETG, which has proven to be significantly stronger than ABS. Update 04/09/16: To make adjusting the belt tension easier, I added a thumbwheel. To create this part, simply heat the head of your m4 bolt and press it into the thumbwheel until the slot or crosshead melts into place. Update 25-05-2016: After approximately 20 hours of printing with this x-carriage, everything seems to be functioning smoothly without any issues. Update 16-06-2016: I'm using the f608zz bearing version and found that the belt clips were slightly too narrow for perfectly parallel belts between the y-slides and the x-carriage. This is likely due to the stiff steel-reinforced belts not wanting to exit straight. However, if you're using neoprene belts, this might not be an issue. I made some modifications by cutting a small amount (about 1mm) off the protruding section of the belt clip. Since this isn't the ideal solution, I've updated the files to version 2, which should address these issues. If you've already printed this x-carriage, cutting a little off might be easier than reprinting entirely. Print Settings: Printer: SmartRapCore Alu Supports: Yes Resolution: 0.26 Infill: 40-60%