Saturday, December 5, 2009

Device, brace attachment

My last post showed how to make the Device. But the Device alone is not sufficient as a piece of adaptive equipment.

There needs to be a way to attach it to the forearm of the person using it. If it cannot be easily attached to a person's existing supports or braces, there are many options.

I experimented with several designs of braces and straps, trying to find something that would be both comfortable and stable. Yet my brace-designing skills proved to be somewhat lacking. I asked a friend for advice, and she suggested I look at bowling supports.

I went to a local bowling shop with my Device (well, with a previous version that turned out to have serious problems and later fell apart, anyway), and started trying on the supports available in the shop and seeing how they fit my arm and how I could use them to secure the Device. I found one that was comfortable and seemed like it would hold the Device securely in place with no additional adaptations or work. So I bought it, and have been using it with the Device for over three years thus far.

I use this one. The only modification I had to make was that since I was wearing it against the front of my right hand and forearm, and this support is designed to be worn on the back of the hand, wrist, and forearm, I could not use the right-hand brace. I instead use the left-hand brace, but upside-down on my right. The curvature in the brace fits my wrist perfectly with just this small change.

For anyone needing to use the Device, and looking for a comfortable way to attach it to the arm, I recommend bowling supports. They are easy to find and significantly cheaper than other orthopedic supports and braces available.

I will have pictures of the Device with its brace, and pictures of it in use, to post in a few days.

Device, design and construction

Obligatory legal note: Design of this Device is copyright Christine Schoedel 2006-2009. The design and construction instructions below are released under v1.0 of the TAPR Noncommercial Hardware License. Full text of the license is at the end of this post.

The materials used to make the Device are:
Aluminum bar, 1"x1/8" This is sold at hardware stores, usually in 4' lengths.
Hose clamp, 1 1/4" size.
Steel wire, 28 gauge.

Tools needed:
Dremel multi-tool with cutting blade and 3/16" drill bit.
Electric screwdriver (optional).
Sanding block, or sanding bit for Dremel.
Needlenose pliers.

All of the supplies are fairly inexpensive. Enough supplies to make three of these, purchased at Home Depot, came to just over $25. That included two types of epoxy, and a spool of wire that ended up unused because it was too thick to bend easily.

Most of the epoxy was not used, as was most of the wire. A single spool of wire and package of epoxy would be enough to make many Devices.

Cut a 1' segment from the aluminum bar. First, measure and mark the aluminum bar where it will be cut.

Secure the aluminum bar, then cut with the appropriate cutting blade/disk on the Dremel.

Sand off the cut end of the aluminum with the sanding block or Dremel bit. Be sure to get this part very smooth, as it will go against the forearm of the person using it.

Next, secure the 1' piece of aluminum, and drill 2 holes through the end that was not cut. These holes should be around 1/3" to 1/2" from the end.

Next, position the hose clamp between the holes and the end of the bar. The loop of the clamp should stick out past the end of the bar, so that it can be adjusted easily. Cut a 3' long piece of steel wire from the spool. Then, wrap the steel wire several times through each of the holes and around the body of the hose clamp, to hold it in place. Use the needlenose pliers to tighten the wire-wrap and tuck in the ends.

The next step can vary slightly, depending on what type of epoxy is used. If a more liquid epoxy is used, squeeze some onto a disposable plate and mix it up. Apply it to the aluminum bar and wire-wrap. Be careful to not get any epoxy inside the hose clamp, but do work it into the wire wrap and be sure it fills the holes in the aluminum bar.

If a paste-type epoxy is used, knead it as directed on the package instructions, and then push and smooth it into place on the Device as above. Be sure to completely fill the holes in the aluminum bar, and to cover the wire-wrap.

Put the Device in a safe place and leave it undisturbed for 24 hours, or until the time the epoxy package says it will take to fully cure. After that time, any rough edges of aluminum should be sanded smooth.

The Device is now ready to be used! The hose clamp size specified above works quite well with dry-erase markers and wide gel pens. For thinner implements such as crochet hooks, simply pad or wrap the handle with tape - electrical tape is a bit more stable in the Device than duct tape.


License information:

The Device is licensed under the TAPR Noncommercial Hardware License v1.0.

Full license text:

The TAPR Noncommercial Hardware License
Version 1.0 (May 25, 2007)
Copyright 2007 TAPR รข€“


Open Hardware is a thing - a physical artifact, either electrical or
mechanical - whose design information is available to, and usable by,
the public in a way that allows anyone to make, modify, distribute, and
use that thing. In this preface, design information is called
"documentation" and things created from it are called "products."

The TAPR Noncommercial Hardware License ("NCL") agreement provides a
legal framework for Open Hardware projects. It may be used for any kind
of product, be it a hammer or a computer motherboard, and is TAPR's
contribution to the community; anyone may use the NCL for their Open
Hardware project. You are free to copy and use this document provided
only that you do not change it.

Like the GNU General Public License, the NCL is designed to guarantee
your freedom to share and to create. It forbids anyone who receives
rights under the NCL to deny any other licensee those same rights to
copy, modify, and distribute documentation, and to make, use and
distribute products based on that documentation.

Unlike the GPL, the NCL is not primarily a copyright license. While
copyright protects documentation from unauthorized copying, modification,
and distribution, it has little to do with your right to make, distribute,
or use a product based on that documentation. For better or worse, patents
play a significant role in those activities. Although it does not prohibit
anyone from patenting inventions embodied in an Open Hardware design, and
of course cannot prevent a third party from enforcing their patent rights,
those who benefit from an OHL design may not bring lawsuits claiming that
design infringes their patents or other intellectual property.

The NCL addresses unique issues involved in the creation of tangible,
physical things, but does not cover software, firmware, or code loaded
into programmable devices. A copyright-oriented license such as the GPL
better suits these creations.

The NCL is identical to its cousin, the TAPR Open Hardware License,
apart from its added requirement that products can be made only for
noncommercial use.

How can you use the NCL, or a design based upon it? While the terms and
conditions below take precedence over this preamble, here is a summary:

* You may modify the documentation and make products based upon it,
provided you do not make more than ten units in any twelve month period.

* You may use products for any legal purpose without limitation.

* You may distribute unmodified documentation, but you must include the
complete package as you received it.

* You may distribute products you make to third parties, if you:
* Either include the documentation on which the product is based,
or make it available without charge for at least three years to
anyone who requests it.
* Distribute only on a non-profit basis, charging no more than the
actual cost of parts, assembly, and shipping.

* You may distribute modified documentation or products based on it, if
* License your modifications under the NCL.
* Include those modifications, following the requirements stated
* Attempt to send the modified documentation by email to any of the
developers who have provided their email address. This is a good
faith obligation - if the email fails, you need do nothing more
and may go on with your distribution.

* If you create a design that you want to license under the NCL, you
* Include this document in a file named LICENSE (with the appropriate
extension) that is included in the documentation package.
* If the file format allows, include a notice like "Licensed under
the TAPR Noncommercial Hardware License (" in
each documentation file. While not required, you should also
include this notice on printed circuit board artwork and the
product itself; if space is limited the notice can be shortened
or abbreviated.
* Include a copyright notice in each file and on printed circuit
board artwork.
* If you wish to be notified of modifications that others may make,
include your email address in a file named "CONTRIB.TXT" or
something similar. Another reason to include your contact
information is to allow users who may wish to request rights for
commercial use to reach you.

* Any time the NCL requires you to make documentation available to
others, you must include all the materials you received from the
upstream licensors. In addition, if you have modified the
* You must identify the modifications in a text file (preferably
named "CHANGES.TXT") that you include with the documentation.
That file must also include a statement like "These modifications
are licensed under the TAPR Noncommercial Hardware License."
* You must include any new files you created, including any
manufacturing files (such as Gerber files) you create in the
course of making products.
* You must include both "before" and "after" versions of all files
you modified.
* You may include files in proprietary formats, but you must also
include open format versions (such as Gerber, ASCII, Postscript,
or PDF) if your tools can create them.


1. Introduction
1.1 This Agreement governs how you may use, copy, modify, and
distribute Documentation, and how you may make, have made, and
distribute Products based on that Documentation. As used in this
Agreement, to "distribute" Documentation means to directly or indirectly
make copies available to a third party, and to "distribute" Products
means to directly or indirectly give, loan, sell or otherwise transfer
them to a third party.

1.2 "Documentation" includes:
(a) schematic diagrams;
(b) circuit or circuit board layouts, including Gerber and other
data files used for manufacture;
(c) mechanical drawings, including CAD, CAM, and other data files
used for manufacture;
(d) flow charts and descriptive text; and
(e) other explanatory material.
Documentation may be in any tangible or intangible form of expression,
including but not limited to computer files in open or proprietary
formats and representations on paper, film, or other media.

1.3 "Products" include:
(a) circuit boards, mechanical assemblies, and other physical parts
and components;
(b) assembled or partially assembled units (including components
and subassemblies); and
(c) parts and components combined into kits intended for assembly
by others;
which are based in whole or in part on the Documentation.

1.4 This Agreement applies to any Documentation which contains a
notice stating it is subject to the TAPR Noncommercial Hardware License,
and to all Products based in whole or in part on that Documentation. If
Documentation is distributed in an archive (such as a "zip" file) which
includes this document, all files in that archive are subject to this
Agreement unless they are specifically excluded. Each person who
contributes content to the Documentation is referred to in this
Agreement as a "Licensor."

1.5 By (a) using, copying, modifying, or distributing the
Documentation, or (b) making or having Products made or distributing
them, you accept this Agreement, agree to comply with its terms, and
become a "Licensee." Any activity inconsistent with this Agreement will
automatically terminate your rights under it (including the immunities
from suit granted in Section 2), but the rights of others who have
received Documentation, or have obtained Products, directly or
indirectly from you will not be affected so long as they fully comply
with it themselves.

1.6 This Agreement does not apply to software, firmware, or code
loaded into programmable devices which may be used in conjunction with
Documentation or Products. Such software is subject to the license
terms established by its copyright holder(s).

2. Patents
2.1 Each Licensor grants you, every other Licensee, and every
possessor or user of Products a perpetual, worldwide, and royalty-free
immunity from suit under any patent, patent application, or other
intellectual property right which he or she controls, to the extent
necessary to make, have made, possess, use, and distribute Products.
This immunity does not extend to infringement arising from modifications
subsequently made by others.

2.2 If you make or have Products made, or distribute Documentation
that you have modified, you grant every Licensor, every other Licensee,
and every possessor or user of Products a perpetual, worldwide, and
royalty-free immunity from suit under any patent, patent application, or
other intellectual property right which you control, to the extent
necessary to make, have made, possess, use, and distribute Products.
This immunity does not extend to infringement arising from modifications
subsequently made by others.

2.3 To avoid doubt, providing Documentation to a third party for the
sole purpose of having that party make Products on your behalf is not
considered "distribution," and a third party's act of making Products
solely on your behalf does not cause that party to grant the immunity
described in the preceding paragraph.

2.4 These grants of immunity are a material part of this Agreement,
and form a portion of the consideration given by each party to the
other. If any court judgment or legal agreement prevents you from
granting the immunity required by this Section, your rights under this
Agreement will terminate and you may no longer use, copy, modify or
distribute the Documentation, or make, have made, or distribute

3. Modifications
You may modify the Documentation, and those modifications will become
part of the Documentation. They are subject to this Agreement, as are
Products based in whole or in part on them. If you distribute the
modified Documentation, or Products based in whole or in part upon it,
you must email the modified Documentation in a form compliant with
Section 4 to each Licensor who has provided an email address with the
Documentation. Attempting to send the email completes your obligations
under this Section and you need take no further action if any address

4. Distributing Documentation
4.1 You may distribute unmodified copies of the Documentation in its
entirety in any medium, provided that you retain all copyright and other
notices (including references to this Agreement) included by each
Licensor, and include an unaltered copy of this Agreement.

4.2 You may distribute modified copies of the Documentation if you
comply with all the requirements of the preceding paragraph and:
(a) include a prominent notice in an ASCII or other open format
file identifying those elements of the Documentation that you
changed, and stating that the modifications are licensed under
the terms of this Agreement;
(b) include all new documentation files that you create, as well as
both the original and modified versions of each file you change
(files may be in your development tool's native file format,
but if reasonably possible, you must also include open format,
such as Gerber, ASCII, Postscript, or PDF, versions);
(c) do not change the terms of this Agreement with respect to
subsequent licensees; and
(d) if you make or have Products made, include in the Documentation
all elements reasonably required to permit others to make
Products, including Gerber, CAD/CAM and other files used for

5. Making Products
5.1 You may use the Documentation to make or have Products made,
provided that each Product retains any notices included by the Licensor
(including, but not limited to, copyright notices on circuit boards).

5.2 You may distribute Products you make or have made, provided that
you include with each unit a copy of the Documentation in a form
consistent with Section 4. Alternatively, you may include either (i) an
offer valid for at least three years to provide that Documentation, at
no charge other than the reasonable cost of media and postage, to any
person who requests it; or (ii) a URL where that Documentation may be
downloaded, available for at least three years after you last distribute
the Product.

5.3 These rights are limited as follows: Products may only be made
for your personal use or for distribution on a non-profit basis (e.g.,
sold for no more than the actual cost of components, assembly, and
shipping) Making more than ten units in any twelve month period for any
purpose is deemed commercial use and is prohibited. These limitations
may be altered or waived through written or email permission obtained
from each Licensor.

TAPR may publish updated versions of the NCL which retain the same
general provisions as the present version, but differ in detail to
address new problems or concerns, and carry a distinguishing version
number. If the Documentation specifies a version number which applies
to it and "any later version", you may choose either that version or any
later version published by TAPR. If the Documentation does not specify
a version number, you may choose any version ever published by TAPR.
TAPR owns the copyright to the NCL, but grants permission to any person
to copy, distribute, and use it in unmodified form.



7.3 You agree that the foregoing limitations are reasonable due to
the non-financial nature of the transaction represented by this
Agreement, and acknowledge that were it not for these limitations, the
Licensor(s) would not be willing to make the Documentation available to

7.4 You agree to defend, indemnify, and hold each Licensor harmless
from any claim brought by a third party alleging any defect in the
design, manufacture, or operation of any Product which you make, have
made, or distribute pursuant to this Agreement.



Hi, I'm Chris. I have a disability that limits my hand function, but that's all I'm saying about it here. What I want to write about here is related to it - the adaptive device I designed and built.

Back in early 2006, I realized I needed a writing tool of some sort that I could use to finish my undergrad work. I spent months searching - I contacted medical device companies, brace/support manufacturers, ergonomic suppliers, prosthetic companies... What I found was that as far as writing tools, there was really not much. Sure, some companies had "ergonomic writing tools" - but those just gave different sizes and shapes of things to grip. What I needed was a writing tool that required no hand usage at all.

So I gave up on finding something already made. I thought a while about what might work, and what I could maybe create, what tools I knew I could use, and went to Home Depot.

Versions 1 through 4 of my writing tool failed. I changed the materials I was using, found a workaround for the epoxy problem, and then made version 5. I've been using it for the last 3 years, for writing and crochet. I call it my Device.

Recently, I've become aware that there are other people who need a writing tool like mine. So I've decided to release the design and assembly instructions under the TAPR Noncommercial Hardware License. A friend and I assembed a few of these last weekend, so we could take pictures to fully document how to make one. The materials used, instructions, and pictures of assembly will be in my next post.