Filament Winder Traverse Calculator

What this tool calculates

Synchronize a level-wind guide with changing spool RPM so the intended pitch stays constant from the core to the full spool.

Formula and method

Spool RPM = line speed ÷ spool circumference. Traverse speed = pitch × spool RPM. As diameter grows, both RPM and guide speed must fall to preserve the same millimetres-per-revolution pitch. Turns per pass = traverse width ÷ pitch.

When to use it

Use this to set or review a synchronized spooler across its empty-to-full diameter range, then tune tension and reversal behavior on the actual machine.

Worked example

At 2 m/min with 1.8 mm/rev pitch, a 90 mm core needs about 7.07 rpm and 0.212 mm/s traverse. At 190 mm fill diameter it falls to 3.35 rpm and 0.101 mm/s.

Assumptions and limitations

Surface speed matches filament line speed without slip and the traverse follows spool rotation or a synchronized controller. This does not calculate winding tension, acceleration at reversals, flange clearance, cross-wind patterns, compaction, or controller tuning.

Common mistake

Do not hold traverse linear speed constant while spool RPM falls; that changes pitch and can produce gaps or crossed wraps.