Trying out a new method to create more complex shapes using PLA.
This wrist brace model was found on Thingiverse and I just gave it a go. The idea behind thermomolding is thanks to the properties of PLA which is the plastic I am using. PLA is liquified at around 200°C but actually softens at around 100°C. This means the plastic becomes malleable and can be shaped just by dunking it for a few seconds in boiling water. However, once it cools, it becomes quite stiff. The print itself it pretty simple, a mostly 2 dimensional object, though probably one of the largest I’ve done in terms of print bed surface area used. It took approximately 5.5 hours to print this, mainly due to the complexity of the lattice and the tool pathing required adds additional time.
This particular design has reinforced bars on the long axis of the brace. The notches on the sides are for adding straps to secure it.
The actual process of thermomolding was straight forward. Dunk the plastic in hot water and you’ve got about 10 seconds to shape it before it starts to stiffen up again. The pro: you can isolate which sections of the print are exposed to the hot water to control where the bending takes place. The con: molding it over your arm might burn you with hot water droplets.
For something that wasn’t designed for my hand size and was molded by an amateur, I’d say the fit is pretty good. Even if it’s not perfect, I imagine it’d be good to squeeze some padding in there.
Overall this print was very successful and I look forward to applying this technique to future prints.