This is a preorder, estimated time of delivery is 2 months (~60 days) from end of preorder period.

The preorder period will last 2 weeks, will end Sunday night, November the 15th at 11:59pm est. After that, all the components will be ordered and should take about 60 days to arrive. Your orders should start shipping soon after the 60 days are up.

Give your Annex K3 the rigid, perfectly square halo it’s been missing.

The Hula replaces the stock top extrusions with a precision-machined steel assembly that delivers true squareness out of the box—no more finicky gantry alignment. Combined with a 12 mm belt upgrade, live shafts, and added mass right where the motion system needs it most, the result is a stiffer, more consistent, and easier-to-maintain XY system.

Key Benefits

• Perfect squareness with precision locating features that make the rails self-aligning
• Eliminates bimetallic effects — manufactured from the same material as your linear rails
• Increased rigidity and mass placed closest to the moving gantry
• +20 mm of Z height by removing the top extrusions (especially useful with taller hotends such as the Chube)
• 12 mm closed-loop EPDM belt upgrade
• Live shafts for smoother motion and easier maintenance
• Uses your existing motors and rails

What’s Included

• Hula
• 8 bearing supports
• 4 shafts
• Shaft spacers
• 4 closed-loop 12 mm EPDM belts
• Pulleys
• 16 bearings
• All required screws

Not Included

• Toolhead
• Linear rails
• Motors
• Motor mounts
• Hotend
• Rail backers (this is a partial kit)
• Anything else not listed above.

Compatibility

Rails

Compatible with rails maximum 9mm wide

Toolheads

Stock k3 toolhead, K3 Metal toolhead, Hula toolhead kit, Mathy toolhead v2

Rail setups
Stock rail setup, Standard K3 cross rail backers, Extra wide rail backers, extra-wide rail backers (when used with a new toolhead)

Motor mounts
Stock printed mounts, Annex steel motor mounts, Hula motor mounts, and most other mounts

Belt tensioners
Stock printed or SLM tensioners (up to 12 mm belts), 12 mm SLM belt tensioners

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