Reddit mentions of OTRMAX 4-Piece 8mm Longer Linear Motion Ball Bearing Double Side Rubber Seal Linear Bushing CNC Part LM8LUU

Pretty generic Not super high quality, but a big improvement over the bearings my printer came with. They were rough.

Oh thank god Reddit is back up! Okay, I think a good bet might be these: https://www.amazon.com/OTRMAX-4-Piece-Longer-Bearing-Bushing/dp/B01MXTYSVL/ref=sr_1_2?s=industrial&ie=UTF8&qid=1498657770&sr=1-2&keywords=lm8luu as it is the correct size and has good reviews.

After doing quite of bit of reading, I went with these:

OTRMAX 4-Piece 8mm Longer Linear Motion Ball Bearing Double Side Rubber Seal Linear Bushing CNC Part LM8LUU https://www.amazon.com/dp/B01MXTYSVL/ref=cm_sw_r_cp_apa_5iPSBb8S68Y2Q

I'm pleased with them so far.

This picture is inland PLA printed at 220 C at various speeds - 60 mm/s on the left to 10 mm/s on the right.

Like most Wanhao i3 pluses, my y axis bearings started going, so I replaced them with these LM8LUUs. I got a lot of ringing. Tightening the belt didn't seem to help. Adjusting print speed and acceleration work, but only with extreme values - the printer was printing fine at 60 mm/s print speeds before the swap, and now I can only get rid of the ringing at 10 mm/s. Similar with acceleration values, originally printed at 1000 mm/s^2, and can get rid of ringing sub 200 (the picture is all 800 mm/s^2). Obviously this is not ideal. I'm out of ideas, but am wondering if this could be a problem with the bearings themselves at this point - that is, if I should replace the bearings again.

I've basically had this problem for about 2.5 years and have posted about it about 6 times, this was the first time anyone knew what it was.

Here's the changes/settings I've made:

EEPROM:

• X axis acceleration: 800
  
• Y axis acceleration: 700
  
• X jerk: 5
  
  Cura 4.2.1:
  
  
• Wall line count: 4
  
• Top Thickness 1mm
  
• Bottom thickness: .7 mm
  
• Print speed: 50 mm/s
  
• Travel speed: 120 mm/s
  
• Initial Layer speed: 25 mm/s
  
  Upgrades to the printer (apart from those already mentioned):
  
  
• Running on a RPi3 with OctoPi/Octoprint
  
• Got rid of the spring tensioners and used these instead https://www.thingiverse.com/thing:1784375
  
• New bearings: https://www.amazon.com/gp/product/B01MXTYSVL/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
  
• https://www.thingiverse.com/thing:1728482
  
• https://www.thingiverse.com/thing:1635585
  
  The rest of my settings tend to vary based on what I'm printing; and my retraction currently isn't dialed in.