KP08 8mm Bore Pillow Block Bearing - Self-Aligning Zinc Alloy Mount

Specifications

• Model: KP08

• Inner Bore Diameter (d): 8.00mm

• Housing Material: Zinc Alloy

• Bearing Insert Material: High-Carbon Chrome Steel

• Centre Height (h): 15mm

• Total Height (w): 29mm

• Total Length (a): 55mm

• Mounting Hole Spacing (e): 42mm (Center-to-Center)

• Mounting Hole Diameter (s): 4.8mm (Fits M4 hardware)

• Base Thickness (g): 5mm

• Shaft Fastening: 2x M3 Set Screws

Key Applications and Projects

• 3D Printer Z-Axis Stabilization: Mounting at the very top of a Z-axis aluminum extrusion to capture the spinning T8 lead screw, preventing it from orbiting and causing horizontal banding on tall prints.

• DIY CNC Routers: Supporting the extreme ends of X and Y axis ball screws to handle the rotational speeds required for high-feed-rate wood routing.

• Automated Camera Sliders: Providing completely silent, ultra-smooth rotational support for a lead screw driving a motorized time-lapse camera rig.

Unlock New Capabilities (Project Evolution) The Dual Z-Axis Upgrade: Is the right side of your 3D printer gantry sagging because it is only supported by a motor on the left? Evolve your machine by adding a Dual Z-Axis! Install a second stepper motor and T8 lead screw on the right side. However, two unconstrained screws can introduce nasty harmonic vibrations. Cap both the left and right lead screws with these KP08 Pillow Blocks at the top of the frame. This traps the kinetic energy, forcing the gantry to move strictly in the vertical plane, resulting in flawless, mirror-smooth layer lines on your 3D prints!

Package Includes:

• 1 x KP08 8mm Pillow Block Insert Bearing (Pre-assembled)

FREQUENTLY ASKED QUESTIONS (FAQ)

1. What is the exact inner diameter of this bearing? The inner bore is precisely machined to 8.00mm, allowing a snug, slip-fit for standard 8mm smooth rods and T8 lead screws.

2. What does "self-aligning" mean? The internal chrome steel bearing has a spherical outer shape that sits inside a matching concave track in the zinc housing. This allows the internal bearing to pivot and tilt to correct minor angular misalignments of your shaft.

3. My bearing arrived crooked inside the housing, is it broken? No, this is completely normal! Because it is self-aligning, it can shift during shipping. Simply insert an 8mm rod into the bore and use the rod as a lever to gently snap the bearing back perfectly straight.

4. What size lead screw fits this bearing? It is universally compatible with 8mm smooth cylindrical rods, T8 lead screws, and SFU1204 ball screws that have been machined down to an 8mm end.

5. How do I secure the shaft inside the bearing? There is an extended collar on the inner ring of the bearing featuring two tiny set screws (grub screws). Tighten these down against your shaft to prevent it from slipping.

6. What size Allen key do I need for the set screws? You will typically need a 1.5mm metric hex key to tighten the M3 set screws.

7. What is the distance between the two mounting holes on the base? The holes are spaced exactly 42mm apart (measured from the center of one hole to the center of the other).

8. What size screws should I use to mount the base to my frame? The mounting holes are 4.8mm in diameter, making them perfectly sized for standard M4 machine screws and M4 T-nuts.

9. What is the height from the base to the exact center of the 8mm hole? The "Center Height" is exactly 15mm. This is a critical dimension when calculating the offset for your motor mounts.

10. Can this bearing support axial (vertical push/pull) loads? It is primarily designed for radial (side-to-side) loads to prevent shaft whipping. While it can handle the light axial loads typical of a 3D printer Z-axis, heavy industrial axial loads require a dedicated thrust bearing (like a BK08 block).

11. Does the bearing need to be lubricated? It comes pre-lubricated with factory grease and features internal seals. However, adding a drop of light machine oil or lithium grease every few months will extend its lifespan and keep it silent.

12. Will this eliminate "Z-wobble" on my 3D printer? It traps the top of the lead screw. If your lead screw is perfectly straight, it will eliminate high-speed whipping. Note: If your lead screw is severely bent, trapping the top can sometimes force that bend into the gantry. Always ensure your screws are reasonably straight first.

13. What is the difference between a KP08 and a KFL08? A KP08 is a "Pillow Block" designed to stand upright, parallel to the shaft. A KFL08 is a "Flange Block" designed to be mounted flat against a vertical wall, perpendicular to the shaft.

14. Is the bearing insert replaceable? Technically yes. If you rotate the insert 90 degrees to align with the relief slots in the zinc housing, it can be removed. However, at this price point, it is usually faster to replace the entire unit.

15. Why is the bearing very stiff to turn out of the box? New bearings feature tight rubber dust seals and thick anti-rust packing grease. It will loosen up and spin incredibly freely after an hour or two of motor "break-in" operation.

16. Is the zinc housing rust-proof? Zinc alloy is highly resistant to standard atmospheric corrosion and oxidation, making it excellent for unheated workshops or garage environments.

17. Can I mount this upside down (suspended)? Yes, the load-bearing capacity is structurally symmetrical. You can mount it hanging from a top plate without any loss of performance.

18. What is the total length of the base? The footprint of the base measures 55mm in total length.

19. What happens if I over-tighten the set screws? If you over-tighten the tiny set screws on the collar, you can strip the delicate internal threads or damage your 8mm shaft. Tighten them firmly, but do not apply excessive brute force.

20. Are the base mounting screws included? No, this listing is for the bare KP08 pillow block assembly only. You must provide your own M4 screws and T-nuts for mounting it to your specific chassis.