Having all those pieces everything I had to do was put them together. The prototype contains 3D printed parts in three different technologies: SLA , SLS and FDM on a pair with standardized parts and even sewed padding. Assembling was a bit like jigsaw but done same way as simulated in Fusion 360 design software and took about 20 minutes. Passive module (mounted on hand) weights 350g and is way too heavy to be mounted directly on corset. Moreover, most users will be in half sitting position with head support right behind them. Following advice of physiotherapy experts, orthopedists and parents I added simple tripod mount to be used with Manfrotto Mini Arm and mounted at the back of any chair. After first try-on (without counterweights) the feedback was very positive. The device follows natural arm movement and doesn’t lock in any position. Looks as if it’s indeed more resistant to misalignment than Magic and Angel Arms. The prototype padding could be better, ladder locks and...

The most important part of any device is that which interact with human the most. In computing it’s interface, in case of exoskeletons and orthopedics it’s padding attached to the body. The padding determines users comfort and experience with the product and if badly designed, poorly manufactured often leads to users aversion. It’s basic rule of all of us, especially the most gentle: children. I experimented with different types of padding and came to the conclusion that less is more. I mean by that it should be unnoticeable like everyday cloth, be soft and drain the moisture out. I feel more confident in hard surface modeling and got help with sewing from my grandma. I cut the template from cardboard and then from mesh fabric. Grandma added trimming and ribbons. Ladder locks were downloaded from GrabCAD rapid manufactured.

Initially all the parts were intended to be printed on desktop 3D printer. This is good approach taken from e-Nable organization – they print prosthetic hands for kids out of charge. Beside being easily available everywhere around the world (thanks for printing services like eg. 3D Hubs) and being relatively cheap desktop 3D printing has its weakness: limited quality. While in most usual cases it’s not the problem (believe me, for most applications desktop printer quality is just great), in arm exoskeletons is one of main factors responsible for locking and jerky movement. Iteration after iteration it was clearly visible that I wouldn’t design another clone of 3D printed WREX. And it wouldn’t have been even possible… Always focused on users comfort and fun of wearing supportive exoskeleton I’ve been trying to keep it slick and friendly. That’s why I reduced number of components and screws to minimum. The less screws means other joining methods must be utilized and this is the reaso...