Proper fit is essential when making an e-NABLE device. A properly fitting device can be worn all day long without discomfort. There are basically two methods available for determining the proper size for an e-NABLE device.
The first method was created by e-NABLE volunteer Peter Binkley. While a little more challenging to learn, this method produces the most reliable results. As a visual approach, it takes into account all of the geometry of both the recipient’s limb and the e-NABLE device, ensuring a comfortable fit. After you’ve learned this method and used it once, you’ll find it much easier the next time.
The second method relies on just a couple of measurements. While easier to use, this method provides less reliable results and may not produce a properly fitting device, so use this approach with caution.
METHOD #1 – THE PETER BINKLEY METHOD
The most effective method for determining the proper scale for an e-NABLE device is outlined in Peter Binkley’s excellent YouTube Tutorials, shown below.
Peter Binkley was honored with a 2017 InfyMakers Award for this methodology.
To get started, you’ll first need to download a copy of Blender, the open-source CAD software.
Next, download Peter’s e-NABLE Device Sizing Blender File and open it with Blender.
Now, watch the videos below (21 minutes total) and follow each step carefully.
e-NABLE volunteer Donna Zimmerman prepared this helpful summary to go along with the videos below.
METHOD #2 – BASIC SIZING FROM MEASUREMENTS
Stephen Davies from Team Unlimbited created an excellent spreadsheet to help determine the optimal scaling percentage for e-NABLE hand devices.
You can download a copy of the in either Google Sheets format or Microsoft Excel format here. You’ll need to make a copy of the spreadsheet for yourself before you can make any edits (“File / Make a copy”, or “File / Download as” in Google Sheets).
Just enter the values for the Recipient’s Measurements (Width of Hand and Length of Hand) in cells B24 and C24. The spreadsheet will then update automatically. Refer to the matrices to determine the best scale for the device type you’re making.
Use this as a general guide, but be sure to carefully examine the specific values in the matrix for the hand type you’re producing. In some cases, a close fit for hand width is more important than a close fit for hand length (i.e. for shorter hand lengths).
For example, a recipient with no fingers may have a hand width of 80mm and a hand length of 80mm. Referring to the Raptor Reloaded sizing matrix, the colored “Confidence %” bar would seem to indicate that 85% is the best scale. In fact, you’d probably be better off with a 125% scale, which would fit the hand width properly. Having some extra length in the device won’t be a problem, but a device that is too narrow would be.
Arm devices require additional measurements. For making the UnLimbited arm, just enter the measurements into the Thingiverse Customizer here. For the Flexy Arm and other arm devices, the spreadsheet above will help you find the best scaling factor.