IEEE Robotics & Automation Magazine - March 2017 - 74

device and of those who expressed an interest in doing so,
2) the building experience regarding sourcing components,
3) manufacturing, and 4) assembly.
Motivation
While the number of respondents in this study was small,
they represented a wide spectrum of motivation for building
their own WoodenHaptics device. The two who had already
built one wanted to produce a public technical demo displaying their corporation's technology along with haptic remote
control. They mentioned as important factors having control
over all aspects of the technology as well as the ability to render high stiffness and forces. The HCI student became interested in haptics after a visit to a surgery simulation facility and
wanted to explore it further without a particular application
in mind and was intrigued by its particular aesthetics. This
person commented: "I really like the look and feel of the
product. It's got this craft feel to it. It's not like a final product-you know, totally refined and built in a factory somewhere. To keep that spirit, I should actually build it myself
rather than getting everything assembled by someone else.
And you could learn how it is actually built, how it works, the
mechanism behind it. I'm curious about it."
The professor thought the device would suit his institution's educational style and suggested that depending on the
course one could exclude or include various moments of the
building experience. For example, an electronics class could
design and make their own H-bridge but have the rest provided, or vice versa.
Sourcing of Components and Parts
The two in the study from the corporation sourced components themselves using the suggested suppliers, except for the
variant in acrylic, which was sourced from a local lasercutting supplier. They had no preference on sourcing parts
from one or several suppliers. The same was true for the
mechatronics students, for whom the sourcing was part of the
learning experience. However, for the self-directed HCI student, who was also currently living abroad, the sourcing of
parts from various vendors was a big obstacle, and he would
have preferred receiving everything as a physical kit. The professor expressed appreciation for the possibility to source and
manufacture independently using the open-source drawings
as well as to buy premade modules, kits, or complete devices.
The sourcing of parts was successful, but not without some
unexpected obstacles. The laser-cut parts aside, some issues
included suppliers sending the wrong cable, some components damaged and in need of replacement, a few parts missing from the bill of materials, and a DAQ card with a
nondefault jumper configuration. Receiving all parts unsorted
was reported to be a bit overwhelming at first.
Manufacturing: Laser Cutting and Making the PCB
The respondents, who lacked access to their own laser-cutting
machine, used an online service for getting the laser-cut
plywood parts, including the material, and used a local com74

IEEE ROBOTICS & AUTOMATION MAGAZINE

march 2017

pany for the acrylic. They reported several issues before
achieving success:
●● The plywood varied in thickness from one order to the
next, and since they were stacked even small deviations
accumulated. Consequently, some screws became too short.
●● The holes were sometimes skewed cut, which mismatched
stacked holes, making it impossible to insert dowel pins.
●● Conversion of file formats one time resulted in millimeters
being interpreted as inches, resulting in comically large
parts.
●● Some iterations on adjusting dimensions were made,
especially for the acrylic version.
While the laser-cutting service provider did not work with
tolerances, asking for sheets of 6.0-mm or fewer thickness and
as straight-cut as possible eventually proved successful. Also,
the fact that changes were possible to make directly in the
vector drawings without using CAD was appreciated. PCBs
were easy to order, but the respondent accidentally soldered a
component in the wrong direction. He found it useful to have
ordered spare parts and PCBs for such mistakes.
Assembly Experience
The first respondent assembled the device independently,
except for the device cabling, which he found the most challenging, for which he sought the assistance of someone more
experienced. Since he eventually built several devices, he accumulated tacit knowledge of the assembly process, using tricks
with such things as tape, tension, and cutting in the right order,
and could pass on this knowledge when supervising the next
builder. He found CAD software (SolidWorks) useful for visualizing the assembly but noted that the CAD software's interface could be confusing to newcomers. The respondent
building the acrylic version had access to the previously built
wooden version, which proved helpful. Acrylic was reported
to be more difficult to assemble due to its brittleness.
Something the respondents would have preferred was to
have the components, both laser-cut and metal parts, sorted
into bags according to which body they belonged to. While
the laser-cut parts were originally placed on different sheets
according to their respective body, minimizing material
waste by combining all the parts on a small number of sheets
was done in the cutting process. The comment suggests that
a facilitator, if the kit is purchased, could help by sorting parts
or that the user could be instructed to do so at the start of
the assembly.
Discussion
We have shown how the WoodenHaptics starter kit can be an
engaging spatial haptics device test bed without many of the
issues usually involved in the craft. It serves to
●● help users understanding the fundamentals of the mechanism; for example, it shows clearly how three motors
combine to generate a force vector at the end of the
manipulandum
●● enable users to incorporate the device easily into their
projects without having to be an electromechanical expert

Table of Contents for the Digital Edition of IEEE Robotics & Automation Magazine - March 2017