Wanhao Duplicator 4S Y-axis pillow blocks & supports

thingiverse

Both the front and rear y-axis shafts on my 4S were wobbling quite a bit after just 3 weeks of use. Wobble was ~2mm at the center of the shaft but it started affecting the print quality. There are many pillow blocks here for Replicator clones, but none of them fit for 4S steel frame + it's not fun to drill that hard steel so I decided to try to utilize existing screw holes. These wont eliminate the wobble 100% (at least not for me as my shafts were already bent) but it will make it insignificant (again, at least in my case). For the front blocks you keep the original flanged bearings, but add additional non-flanged bearings to keep the shaft straight near the pulleys. Print one of each pillow blocks and 2 of rear supports. You probably need to rotate pillow blocks 180 degrees in your slicer around x or y axis. Printed these from PLA 0.2 layer height, 15% infill, 2 shells. No supports needed if any kind of cooling exists. Additionally needed: -2pcs M3x15mm screws. -4pcs 5x11x4mm bearings. These wont require much dismandling. How I installed them: Front: -Remove side plastic frames (6 screws on each side) then stock front pillow blocks (2 screws each on side). -Wiggle the shaft out from up side by turning other end towards back of the printer. -Remove stock blocks and plastic spacers. They wont be used anymore. -Loosen one of the pulleys to help installing new blocks. -Install stock flanged bearings as inner bearings for the new block. -Install new (non flanged) 5x11x4mm bearings as outer bearings. Push them in enough as the shaft is not long enough if you leave them just at the edge. -Intall shaft back in the same way you removed by positioning the end of which pulley you DID NOT loosen at the front first. -Push new block to the shaft to that end of which pulley you DID NOT loosen. -Push the second block to the shaft and wiggle the shaft in its place. Rear: -Loosen left side Z-axis slide upper mounting and tilt it towards front much as it's able to move (just ~2cm) to help manouvering rear Y-shaft. -Loosen left side stock pillow block. Then by some patience you should be able to remove it, plastic spacer and pulley from the shaft. Dismount the right side from the pillow block to help moving the shaft around. You need to bend the shaft a bit to remove all junk. You can of course disassemble the unit more but I was able to install new bearings on the shaft like this. -Push 2 pieces of 5x11x4mm bearings to the shaft and reinstall the shaft with stock parts. -Tilt the Z-axis slide back in it's place. -Replace outer most Z-axis slide screws with M3x15 screw found in spare parts bag that came with the unit and install rear support blocks to these points (keep the stock slide supports of course). -Slide the previously installed bearings in the supports. Remember to check X-axis alignment before tightening those pulleys and bed leveling before printing anything. NOTE: Front blocks were really tight fit for gantry to fit at the very end towards front. Check that yours is able to move far enough (towards front) and if needed, file the block corner a bit.