Silentblock SC8UU by MKSA

Last crawled date: 3 years, 1 month ago

When I started with my Geetech Prusa Al, the noise, a mix of humming, hissing, rattling ... almost drove me mad. I had noticed the smooth rods excessive play in the bearings. Worse, they are regular "soft" stainless steel diam 7.92mm ! May be they produce it in that size to sell them as metrinch ? (standard metric 8mm and archaic 5/16 " ). Big savings anyway and it seems to be quite common. I replaced them with suitable hardened rods miked at 7.95 mm.
Now, to reduce further any play and compensate for slight misalignment, I designed these bearings where the LM8U is held by two O rings. Depending on the O ring size, material, shore hardness one can make the liaison more or less flexible. This somewhat allows to constrain the bearings when they are mounted thus eliminating any play.
Yes, tie wraps and flexible frame achieve about the same result but frankly ?
It is a drop in replacement for the SC8UU. Use self tapping screws (old printers are a good source for perfect ones). Regular machine screws are not really fit for plastic but will work. No real need to tap, just make sure the hole is the screw diam mius the pitch (eg M3: 3-0.5 = 2.5)
PS: These have been printed in ABS with an unimproved Geetech. I don't use them anymore as I went Igus (see my other things). Of course the quality while not bad is not comparable to what I am now getting. Biggest gain due to replacing the Z lead screws and one motor. See my other things.