Enabling R&D – Thermo-forming Trials

Over the past few months, we have shared numerous stories about the beautiful children that are receiving 3D printed hands that are being created by our amazing volunteer e-NABLE community – but have failed to share much of the “Behind the scenes” research, development and design that goes on in our Google+ group where we now have over 5000 members and quite a few of them are donating their time, talent and creativity to help us improve these devices further.

While the news articles about smiling kids with new colorful 3D printed limbs is always a treat to read – we think it is high time we start showcasing some of our volunteers and the incredible work they are doing in their garages, their universities, their basements, their labs and their classrooms.

Volunteer, Adam Kitz, has gathered some of our recent R&D projects to showcase and will be featuring a few each week so that we can share a bit about what our volunteers are working on and showcase some of the most interesting ideas coming out of our group that will be tested and eventually released for use!

Thermomesh Testing

Volunteer Andreas Bastian, 3D printing research scientist at Autodesk, has been experimenting with a variety of thermo-mesh (thermoformed) designs for palms and gauntlets since October of 2013. These designs allow the plastic hand caps and gauntlets to be warmed with hot water and molded around the recipients limbs to create a more custom fit.

Andreas shares: “I work with a recipient who has been testing an integrated thermomesh palm since February 18th and he’s liked it so far, though we’ve made a couple of size adjustments (made it too loose last time around). One potential challenge we encountered is that the thermoformed PLA is still more brittle than ABS and will crack under a direct blow (a baseball in this case). I’m looking into integrating a ninjaflex/sugru gripping surface on the exterior of the mesh to help with functional grasping and to mitigate direct impacts.”

An update on April 29th shows a couple of stress fractures in the gauntlet after 2 and a half months of active use and some damage after catching a baseball.

Our volunteers in the R&D group have also been testing a new thermo-formed gauntlet designs that print out flat on the print bed, remove the need for support materials and can also be heated and formed around the recipients forearm (while wearing a protective sock to remove the chance of harm) and provide a more customized and more comfortable fit.

Andreas shares an update from his 4/29/15 session with his beta testing recipient:

• I’ve updated the wist hinge thickness so that the wrist pins don’t stick out on the inside of the joint.
• I’ve updated the “Full Wrap” thermogauntlet to provide better load distribution

“My recipient liked the new full-wrap gauntlet for a number of reasons. It was easy to slip on and off, in part because there wasn’t yet a binding in place, and there was very little play in the component, unlike the stretch of the velcro in velcro-secured gauntlets. The most important thing I saw was that he no longer had the impression of the edge of the velcro strap on his forearm, the cause of which I’ve attempted to illustrate below as I think it is a pervasive flaw in most gauntlet designs currently available. Because the velcro slots must be printed exactly horizontally (at least in the traditional print configuration), the velcro does not describe the roughly conical surface of the underside of the forearm. Instead, it forms a bisecting plane with the forearm and concentrates the restraining load of the gauntlet on the rear edge of the velcro, sometimes causing irritation.”

One of our favorite things about working with recipients – is when they use their test hands for a while and then come up with great ideas on their own based on needs that designers don’t often think of because they aren’t the end user.

Andreas recently shared this update from his Beta Tester:

“I wanted to share a discovery my recipient and test pilot Kieran made earlier this week.  He’s a big tech deck fingerboard fan and noticed that the adhesive grip strips on the fingerboards were a nice grippy foam, so he started putting them on his fingers and palm.  It’s great stuff and though the strips need a little glue to keep them secured, they do add a nice soft friction to the fingertips and palm.”

There is a lot of work that still needs to be done with this design, but thankfully we have some fabulous beta testers that are working with our teams to give us feedback and help improve these hands so that we can find ways to create stronger and more comfortable devices.

To learn more about these designs – please visit our Forum pages for the Thermomesh Gauntlet and Palm designs!

If you are interested in contributing your skills and knowledge, design work or would like to help print and create hands for those in need – please visit our “Get involved” page and sign up to become a volunteer!

Help us to keep “Enabling the future!”