8mm and 2mm Spacer for M5 Screw

When I bought my first 3D printer, the CTC A10s, I was AMAZED at how much there could be wrong with a brand new printer, but given the price differential between it and the machine it set out to copy, perhaps I shouldn't have been so surprised.

I was actually pleased with how much was wrong with this printer I was getting my feet wet with as it would serve mostly to hasten my knowledge and understanding of FDM 3D printing.  :)

One of the many problems CTC injected into this machine to cut costs was to install POM wheels with only a single centered bearing.  Creality machines, and practically every other machine that uses these POM wheels have two bearings and a flat washer in the center.  One day into my 3D printing experience, one of these single bearing rollers on my X carriage began wobbling and jamming on the X axis.  I looked at the Creality POM wheels and saw how they were different, so I ordered a complete set of 15 from Creality.  Each of the original single bearing rollers had two 11mm tall spacers.  With the double bearing rollers, I needed 8mm tall spacers for either side so I made these 8mm spacers.  I had also ordered a bulk bag of M5 concentric nuts since CTC only included three on one side of the heated bed, and one on the X carriage.  There were no concentric nuts for adjustment on either side for Z axis travel.  The concentric nuts I ordered were just the cheapest ones I could find for M5 screws, and they turned out to be smaller on both external dimensions than the four that came with the printer, which is why there is also a 2mm spacer as part of this model.  If you're using the 8mm tall concentric nuts that require a 10mm wrench, ignore the 2mm spacer as it serves no purpose for those using proper hardware.  :)

I replaced all the rollers for both the X and Z axis' and decided to leave the heated bed rollers for a later day.  Four years later, that later day has finally arrived.  The Y axis rollers without concentric nuts require only one 8mm spacer per, and those with concentric nuts will be installed with no spacers at all since the nuts themselves are 8mm tall.

I included before and after photos of the bed roller replacement and a photo of the Z axis rollers I installed years ago.  Disregard the fact that the old spacers are indigo, and the new spacers are green.  I'm on a green kick lately, but not so much so that I feel like replacing all the spacers that have been working perfectly all this time.

Of course these can be used on anything that uses M5 screws and needs either an 8mm or 2mm tall spacer.  If you intend to use these on a printer that will be working in a heated enclosure, print these out of nylon or some other material that will survive the heat.  If you're only printing PLA or PETG, and aren't using a heated enclosure, print them out of whatever you like.

The outside diameter of these spacers is 9.5mm.  The original nylon spacers were 9mm.  I made these slightly thicker because I would be printing these out of PLA and solid, but I don't recall why I decided on 9.5mm as opposed to 10mm.  Perhaps I was concerned that a 10mm diameter spacer would damage the dust seals on the Creality bearings.  I honestly can't recall, it was four years ago, but there certainly was some reason for this…  I just included that piece of information so whomever might want these will know if it suits his or her application.