Smartrapcore Alu linear rail conversion kit for 608zz bearings - New motor mounts!

thingiverse

Update 29-07-17 The full parts tray STL did not contain the tensioner - fixed.\nUpdate 01-Jul-17 - Revised motor mounts have been added. These have been updated for use with the linear rail conversion. I removed the smooth rod clamp and made a 1.5mm shift of the motors towards the center of the printer, improving the geometry of the belts from y-slides to motors. This geometry relies on using 608zz/f608zz bearings and 16t pulleys. The right mount has a 2.5mm hole for tapping a screw for an endstop if you want to place one there.\nPlease remember this: Attach the motors before attaching the mounts or trying to get the bolts, otherwise you'll go mad! Use plain hex-headed M3 bolts, not cap-headed Allen key screws.\nUpdate 04-Feb-17 - I realized that the R y-slide has not got enough cut-away for the higher-plane belt to rub against. This was corrected in the STLs above. It's been working well since installation.\nDescription: Convert your SCALU printer to linear rail (MGN-12H) Hiwin or their Chinese equivalent, getting rid of x and y smooth rods. The kit is designed to be as minimal and smarttrap-derived as possible.\nYou can keep your rear pulley holders or replace them with a better-supported version like these: http://www.thingiverse.com/thing:1655402. If you also use f608zz bearings, consider the belt geometry. These motor holders provide the correct geometry: http://www.thingiverse.com/thing:1741525.\nYou'll need 3 MGN-12H rails - two for the y-axis are 275mm and one for the x-axis is either 340mm or 440mm, depending on your printer's size. It's worth buying slightly longer rails than needed and then cutting them. Use an angle-grinder if necessary.\nAlso get at least 4 M3 half-t nuts and M3 bolts, plus a selection of short 6 and 8mm M3 bolts.\nI printed the parts in PETG - they're strong and have a slight elasticity that grips screw threads well. Print them with 90 or 100% infill for a reason. The x rail is the fiddly part, as hole spacing on rails varies between manufacturers. So I didn't include holes to mount it.\nThe x carriage has balanced belt tensioning - you'll need a long M4 bolt (about 60mm) to connect the moving belt clip. See more details here: http://www.thingiverse.com/thing:1582049\nAttach the y-axis rails to the frame with T nuts, then attach the y-slides. Decide where to cut your rail for reasonable screw positioning into the underside of the y-slide. Cut the rail and mark holes - drill the y-slides to 2.5mm. Attach the rail to the y-slides with M3 bolts.\nI also bonded it with epoxy for extra security.\nPress or heat-press 4 M3 nuts into the adaptor plate, which is screwed to the x linear rail carriage. Use short screws to attach it to the carriage and the printed x carriage. Then reattach your belts, hot end, etc... \nThere's definitely less play at the nozzle now, and I expect grid levelling will work without the characteristic sag in the middle.\nI accept that there are probably better designs for a CoreXY gantry using linear rails, but if you want to keep your machine similar to the SmartRapCore with improved function, this might be the way to do it.