LW-PLA: active foaming vs pre-foamed filament for RC aircraft

Identify the LW-PLA process before choosing a profile

The LW-PLA label covers two documented processes here. colorFabb describes its LW-PLA as active: the material expands during extrusion, and the manufacturer says temperature and flow can control foaming. It claims up to 65% lower weight for its product than standard PLA; that remains a colorFabb statement, not a property of all LW-PLA. Polymaker describes its PolyLite LW-PLA as pre-foamed during manufacturing. The pages cite weight-sensitive uses including RC aircraft but provide no mechanical comparison between the two products.

To interpret 'up to 65% lighter', take a purely arithmetic example: reducing 100 g by 65% leaves 35 g. This calculation is not a prediction for your file and does not describe a weighed aircraft. The colorFabb page supplies no conditions here for a comparison with PolyLite LW-PLA. Record the exact claim and the missing comparison basis before using it in a mass budget. Do not turn an upper-bound marketing statement into an expected saving for every object, or treat that arithmetic remainder as the mass specified by a model designer.

Active foaming: Prusa’s temperature and speed example

The Prusa Knowledge Base describes LW PLA as an active foaming material that can expand 2.3 to 3 times its original size during printing. According to that documentation, expansion depends on nozzle temperature and print speed, because those two settings together define how much heat the filament receives. Faster speeds need a higher temperature to reach the same expansion. Prusa also states that maximum expansion, three times the original size, is reached around 240 to 250 °C, with a recommended nozzle range of 210 to 250 °C and a bed between 55 and 60 °C.

The 2.3-to-3 expansion, 210–250 °C range and 1-to-0.35 multiplier are the indications on Prusa’s page for the LW PLA it describes; do not automatically transfer them to colorFabb or another spool. Prusa links expansion, temperature and speed in its example. colorFabb says temperature and flow can control foaming for its own reference. These sources identify settings to consult, but do not establish a shared curve or guaranteed setting.

Pre-foamed: Polymaker’s product description

Polymaker describes PolyLite LW-PLA as pre-foamed during manufacturing and says it does not foam at the nozzle depending on temperature. The reviewed passage gives no extrusion multiplier or calibration procedure; it points readers to the recommended settings and flags stringing. Check those settings for this reference instead of assuming a standard multiplier or calibration identical to ordinary PLA.

Polymaker flags stringing and suggests refining temperature and retraction. The reviewed passage is not a complete settings table: locate the recommendations for the actual reference before preparing a profile. To keep a useful record, note their version, the selected profile name and any applied changes. A pre-foamed product does not mean that every temperature or retraction setting produces the same result on your setup. Preserve the distinction between what the product description states and what the separate profile actually contains.

Extrusion multiplier: scope of Prusa’s guidance

For active foaming filament, Prusa’s documentation links the extrusion multiplier to the foaming factor and gives 1 to 0.35 for the example on its page. This is not a universal range for every LW-PLA. colorFabb says temperature and flow can control foaming in its product, but the reviewed passage supplies no shared measurement procedure. If you choose to test a spool on your machine, record it as an observation for that spool, profile and settings; a wall measurement alone does not establish an aircraft wing’s strength or mass.

If you run a trial on your setup, record at least the exact reference, profile, temperature, speed and multiplier, then limit the conclusion to that trial. The Prusa settings cited above belong to its example; the colorFabb and Polymaker pages reviewed here do not describe a shared calibration procedure. No test was conducted for this page.

RC aircraft: match spool, design and project criteria

The manufacturers list weight-sensitive uses: colorFabb includes RC aircraft and drones; Prusa mentions thin-wall models and internal structures, including 3DLabPrint aircraft. These examples do not establish that active filament suits every single-wall design or that the other product would produce walls that are too thin. Check the design assumptions and the instructions for the exact spool before choosing.

For a model build, record the material specified by its designer, the supplied settings and how any stated mass is defined: printed components alone or an equipped assembly, for example. This suggested project record does not qualify an aircraft. If you later record a mass, identify the items actually weighed and the profile used. That lets you distinguish your build's result from colorFabb and Polymaker product descriptions without assigning a difference to foaming process alone. A comparison with an equipped model needs the same list of included components before the two totals are meaningful.

Common traps: stringing, borrowed profiles, speed changes

The first documented caution is Polymaker’s stringing note for PolyLite LW-PLA, with advice to tune retraction and temperature. The source does not compare stringing with colorFabb’s active product or link it to higher foaming temperature. For retraction checks, use the existing retraction settings guide; its advice is separate from the LW-PLA manufacturer guidance.

The second trap is transferring a profile without checking its assumptions. Prusa’s page links speed and expansion for its example; it does not document here how nozzle diameter or another brand affects a colorFabb or Polymaker profile. If you change speed or reference, consult the relevant manufacturer settings and record the differences. colorFabb’s 65% figure remains a product statement; none of the three sources describes a specific aircraft weighed after printing.

Sources and limits

• LW-PLA Filaments – Lightweight PLA for 3D Printing | colorFabb
• Prusa Knowledge Base — LW PLA / PolyLight 1.0, active-foaming example
• Polymaker — PolyLite LW-PLA, pre-foamed product description and FAQ

We organize manufacturer and community documentation; we have not measured these products ourselves. The manual for your exact model takes precedence over general guidance.