Light Weight PLA

[Simon Chaddock]

I have recently bought some lightweight PLA (LW-PLA).

It is the material that 'foams' as a result of the temperature used to melt the filament in 3D printing.

It has been around for some time but initially was rather expensive and also required a replacement "hot end" of the printer as most budget printers would not run reliably at the 240 C temperature required for maximum "foaming".

 

It is possible to print a complete airframe in this material with significant weight savings and some have already done this, the Plane Print Seagull springs to mind. However my chosen use for printing is to create "parts" for planes, usually single wall structures, where the attributes of both the material and the printing process can be used for maximum benefit.

 

The nose cone is an example of a printed part as used on my XPS Hawker Sea Hawk.

As I happen to have a 'spare' nose cone in normal PLA I though it would be an interesting comparison to print a duplicate in LW-PLA.

To keep within the hot end limitation of my printer I kept the extruder temperature to 210 degrees and accepted the reduction in the foaming.  

It is a single wall 'vase' printed item.

 

The weight difference, just 32%, is obvious. The LW material is rather more flexible but has a degree of flexibility so it will 'spring back' from a mild defection. Normal PLA is significantly stronger but brittle in comparison.

There are some hidden advantages as well.

To achieve even the 7g in PLA required the thinnest possible wall and layer thickness (0.3 and 0.15 mm) that would print satisfactorily. With the 'foamed' PLA the effective wall thickness is doubled giving both a superior quality print and surface finish yet at 1/3 the total weight.

An even more subtle advantage is the foaming process ensures a superb bond between the layers so unlike normal PLA the finished article is virtually as strong across the print as along it.

Obviously the reduced strength of LW-PLA does mean some limitations but for printing 'parts' its reduced weight does increase the scope of what might be usefully created.

We shall see.      

[Andy Stephenson]

I have a couple of planes printed in LW PLA but I found in the heat of the summer under the full glare of the sun that it started to melt and sag in places like the canopy on my Eclipson Pitts. There is now a high temperature version of LW PLA which should hold up much better on a hot day.