Imperial Ball Bearings Print in Place | R4 R6 R8
Print in Place R Series Bearings | R4 R6 R8
Inch sizes, printed fully assembled. For everyone whose shaft is measured in fractions.
Three imperial deep groove bearings that print in one piece and spin off the plate. R4, R6 and R8, the three sizes you actually run into.
Why a separate set
If your shaft is half an inch, a 608 will not help you. The R series is its own dimensional system, and it dominates in workshops that never went metric. R8 in particular turns up in skateboards, lathes, wheelchair wheels and small motors, and it sits in the top ten best selling bearings alongside 608 and 6203.
What is included
- R4 · 1/4 × 5/8 × 0.196 in · 6.35 × 15.875 × 4.978 mm · 11 balls
- R6 · 3/8 × 7/8 × 7/32 in · 9.525 × 22.225 × 5.556 mm · 11 balls
- R8 · 1/2 × 1 1/8 × 5/16 in · 12.7 × 28.575 × 7.938 mm · 10 balls
Same clearance, verified the same way
Ball to race clearance is 0.150 mm, measured solid to solid in CAD, exactly as on my metric set. If you have already tuned your printer on those, these behave identically. Nothing new to calibrate.
Printing
Flat as supplied, no supports, three walls, 25 percent infill. Turn ironing off, it welds the balls to the outer race.
R4 is the delicate one, with 2.78 mm balls. Drop to 0.12 mm layers for it. R6 and R8 are comfortable at 0.20.
Straight off the plate they feel locked. Grip the outer ring, twist the inner one firmly until it clicks free, then spin it a few times. That is normal and by design.
Working in metric?
The metric set is on my profile: 36 sizes covering 608, the 6000, 6200, 6300, 6800 and 6900 series, built from this same geometry.
