A ball bearing is a bearing used for low friction movements across an axis. They are cheap and widely available, mostly from the skateboard industry.
Ball bearings are usually closed and have their own lubrication, so no additional lubrication is needed.
The first digit of the model name refers to the kind of bearing, the second digit to its robustness. The third digit is usually the bore size in mm. Then follows the bearing type letters.
There are several types of ball bearings:
|ZZ||Shielded, double||Sufficient for most RepRaps.|
|2RS||Sealed, double||For keeping out generated dust and grit (e.g. from a Milling and Drilling Head)|
|V||Non-contact seal, single|
|VV||Non-contact seal, double|
|DDU||Contact seals, double|
|NR||Snap ring and groove|
The most common ball bearings are:
|Abbrev.||Inner D.||Outer D.||Thickness||Notes|
|608||8 mm||22 mm||7 mm||A common roller skate bearing used extensively in RepRaps.|
|688||8 mm||16 mm||5 mm|
|686||6 mm||13 mm||5 mm|
|626||6 mm||19 mm||6 mm|
|625||5 mm||16 mm||5 mm|
|624||4 mm||13 mm||5 mm|
|623||3 mm||10 mm||4 mm|
|603||3 mm||9 mm||5 mm|
|633||3 mm||13 mm||5 mm|
The 608 size ball bearings in particular are extremely low cost. Their 8 mm bore size almost forces us to mount them on:
- M8 threaded rod or M8 bolt, as in the Mendel Z-axis; or
- 5/16 inch bolts or 5/16 inch threaded rod, as in the SAE Prusa Mendel; or
- something like a plastic bearing clip 01 (still experimental).
They will need shims to fit snugly on threaded rod. Thin aluminum (pop cans) often works.
The 626 size ball bearing have a 6 mm bore size. We can mount them on:
- M6 bolts and M6 threaded bar, as in the RepRapPro Huxley frame assembly.
The 624 bearing have a 4 mm bore size. We can mount them on:
- M4 bolts, as in the Mendel X-axis; or
- #8 bolts (4.1656 mm) with a little tweaking, as in the SAE Mendel.
The 626 and 624 bearings seem to cost more than 608 bearings, but M6 and M4 bolts and threaded bar cost less than M8 threaded bar and bolts, so it's almost a wash.
|Vendor||From||8 mm||6 mm||5mm||4 mm||3 mm||Additional notes|
|Alfa-Tech3D||DK|| 608RS 608ZZ
||From 1 pcs. Delivered Worldwide.|
|Folger Technologies, LLC||US||608Z||626Z||625Z||624Z||623Z||Offers various other bearings, high quality, and fast shipping.|
|3D Acessories Hub||India||608z Bearing||624z bearing|
|Charlie's 3D Technologies||BE||608ZZ||624ZZ|
|ReprapUniverse.com||Netherlands||608ZZ||624ZZ||High Quality Miniature Ball Bearings for Reprap 3D Printers. Sells per 1 piece / 10 pcs / 60 pcs - Cheap International Shipping.|
|FunReprap France||FR|| 608RS
|Envoi Rapide tous les jours pour toute l'Europe. D'autres references disponibles, Roulements à billes ou linéaire LM6 - 8 - 10 - 12 UU - 16014 etc...|
|VXB Ball Bearings||US||many||many||many||many|
|Makeralot||CN|| 608ZZ 688ZZ
|| 686ZZ 626ZZ
|| 625ZZ 695ZZ
|| 624ZZ 634ZZ
||Shipping worldwide. Also available 6900ZZ 10x22x6mm Ball Bearing, 16014 Ball Bearing, etc.|
|RepRap Portugal||PT||608Z||626Z||625Z||624Z||623Z||Dedicated Portuguese community, we also establish connection between the Portugal local sellers.|
|CIE Auto Source||CN||many||many||many||many|
|Wholesale Skateboard Bearings||US||608SS||Minimum 80 pcs.|
|Imprimante 3D France||FR|| 608ZZ
608ZZ (10 pcs)
626ZZ (10 pcs)
624ZZ (10 pcs)
|623ZZ||Paris area. Also available: MR105ZZ (5-10-4), 6700ZZ, MR126ZZ|
|chartup.com System Engineering GmbH||DE||533Z|
||Sell individually or in packs. Fast $2 shipping within Australia for small orders.|
||626ZZ||625ZZ||624ZZ||623ZZ||Ship to worldwide.|