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Macro: Tip Forming

What it does

Happy Hare's standalone filament-tip-forming macro - the default way to get a clean, hair-free tip before an unload, working similarly to PrusaSlicer/SuperSlicer's own tip forming. See Feature: Tip Forming and Purging for the concept, the alternative methods (toolhead cutting, slicer-controlled), and the full step-by-step tuning workflow using MMU_TEST_FORM_TIP - this page doesn't repeat that, just the menuconfig view of the variables it tunes.

Where it's applied

_MMU_FORM_TIP, defined in mmu_form_tip.cfg. Active whenever form_tip_macro: _MMU_FORM_TIP in mmu.cfg (the default) - runs through five steps in order: ramming, nozzle separation, cooling moves, an optional skinnydip pass, then parking the result for eject/inspection or the next unload step.

Kconfig.form_tip is sourced unconditionally in the installer, so this screen is visible in menuconfig regardless of whether tip forming or toolhead cutting is actually selected - unlike Toolhead Tip Cutting's screen, which only appears once a toolhead cutter is enabled.

Happy Hare zeroes pressure advance for the duration of the macro call, so the ramming/cooling moves aren't distorted by it, then automatically restores whatever value was active beforehand once tip forming completes - nothing to configure or restore by hand.

Configuration

menuconfig: Tip forming (_MMU_FORM_TIP) screen, showing the ramming, nozzle separation, cooling, skinnydip, and parking steps

_MMU_FORM_TIP_VARS in mmu_macro_vars.cfg, reachable from menuconfig's Macro Variables → Tip forming (_MMU_FORM_TIP) screen shown above, grouped by the same five steps the tuning workflow walks through. Full variable table: Macro Variables: Tip forming.

Hotend starting points

cooling_tube_position/cooling_tube_length are toolhead-specific - tuning from scratch is slow, so start from your hotend's known geometry rather than the shipped default:

Hotend cooling_tube_position cooling_tube_length
DragonST 35 mm 15 mm
DragonHF 30 mm 10 mm
Mosquito 30 mm 20 mm
Revo 35 mm 10 mm
RapidoHF 27 mm 10 mm

See also