The productivity center at Sandvik Coromant wanted to capture high quality video inside their CNC machines to demonstrate machine operations to customers. Their existing security cameras provided low quality video. GoPro cameras were selected to replace them but the stock polycarbonate enclosures failed when exposed to coolant. An engineer designed and 3D printed a prototype for an aluminum enclosure with a tempered glass viewport and waterproof buttons and cord grips. Testing showed the enclosure resisted coolant infiltration and allowed wireless remote control of the GoPro. Manufacturing 5 enclosures and equipping them with GoPros cost $4,710, saving money compared to purchasing commercial enclosures.

1. August 11, 2015
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Development of Waterproof GoPro Camera Enclosures for use in CNC
Machines
Dallis Guillemin
Sandvik Coromant
17-02 Nevins Rd
Fair Lawn NJ 07410
INTRODUCTION
The ability to capture video from inside CNC machines is a very important feature of the
productivity center at Sandvik Coromant. Functioning as a showroom for customer
demonstrations as well as a fully functioning machine shop, the productivity center relies on
video footage captured in the machines to give customers and employees alike a close look at
what is happening inside the machines. Despite
being equipped with some of the industry’s
most capable CNC machines, the productivity
center has never been able to provide high
quality video of them in action. The cameras
currently fitted inside the machines are
essentially security cameras, designed to
provide video records over long periods of time
with limited maintenance. While these cameras
are capable of taking video recordings in the
machines, they are a far cry from high quality.
It was determined that the productivity center would benefit from having cameras in the
machines that were capable of producing full high definition (HD) video footage, so new
cameras would need to be purchased.
After an analysis of available cameras, it was determined that the GoPro line of cameras
(shown in Figure 1) would be perfect for use inside the machines. The cameras can record 60 to
120 frames per second, which is much better than the typical security camera which rarely
exceeds 30 frames per second. Furthermore a resolution of 1080p can be recorded by these
cameras, making them full HD. In addition to the high quality video, GoPro cameras are low
profile, easily operated, and relatively cheap (about 300 to 500 dollars per camera, depending on
the model). Based on these features, the GoPro was
selected as a candidate to replace the security
cameras.
GoPro cameras come with a waterproof
enclosure made of polycarbonate plastic, which
was initially used in the machine to protect it from
the coolant spray used during many machining
processes. After just a short time in the machine,
small micro-cracks were discovered on many
surfaces of the camera enclosure. The cracks led to
failure of the enclosure and its mounting unit
(shown in Figure 2). This problem, combined with
Figure 1. GoPro Hero 4 camera line
Figure 2. Failure ofthe Camera Mount after
exposure to the coolant

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a lack of access to a live feed HDMI video cord, made the stock polycarbonate enclosure
unacceptable for use inside the machines. An enclosure would need to be acquired that was not
only waterproof, but coolant-proof as well. This enclosure would also need to support live feed
wires from the camera, which would be a necessity for classes and demonstrations involving the
machines. After no such enclosure could be found, it was determined one would be designed in
house.
DEVELOPMENT
The enclosure which was designed to meet these design criteria needed to be made of
something other than polycarbonate plastic. After acquiring the chemical data sheet for the
machine’s coolant (Fuchs Ecocool S761 B) [1] a series of plastics and other materials were
considered. Plastics are light and cheap, and could be easily machined at the productivity center
to create the final product. Unfortunately, research showed that most plastics would be
completely or partially dissolved by the coolant’s chemicals (Detailed in Figure 3). As a result,
aluminum was chosen as the material with which the enclosure would be constructed. Aluminum
is relatively light and cheap, and
could be machined easily in the
productivity center. Due to the poor
performance of many plastics,
tempered glass was chosen to cover
the viewport of the enclosure.
As the enclosure begun to
take shape, the issue of wire access
to the camera was given attention.
The wires would need to enter the
enclosure to connect to the camera,
and be waterproof once installed. Watertight cord grips were chosen to complete this task. The
cord grips were large enough when open to allow the wires to pass through the housing wall, but
could then be tightened to seal around a smaller diameter. A schematic of a typical water-tight
cord grip can be seen in Figure 4.
To attach the lid to the
housing, a hinge was considered due
to its convenience. The lid and
housing would be one unit, preventing
the possibility of the lid and housing
becoming separated. Once closed, the
lid would be secured to the housing
tightly through the use of thumb
screws. Between the hinge and
screws, adequate sealing pressure
could be achieved on the oil ring
between the lid and housing.
The most difficult aspect of
the design involved the incorporation of watertight buttons which would allow the camera to be
used fully when sealed inside the enclosure. Because the buttons would need to be moving parts,
Figure 3. Polycarbonate’s performance when exposed to
Naphtha and Ethyl Acetate,two of the primary solvents in
the coolant. D indicates very poor performance. [2]
Figure 4. Components of a typical Cord Grip, exploded
for reference

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it was not easy to visualize a
watertight solution to the problem.
Eventually a solution was
discovered while studying the
design of camera enclosures made
for scuba diving. These enclosures
had buttons which were comprised
of pins, o-rings, and return springs.
With some engineering, a working
button was designed for use on the
GoPro enclosure. A drawing of the
button is shown in Figure 5.
MANUFACTURE AND TESTING
Once fully designed, the camera enclosure
was modeled in Unigraphics NX. A prototype of the
solid model was then created using a small desktop
3D printer. Shown in Figure 6, this model was used
to test the tolerances and visualize the construction.
In addition, the model made visualizing the tool-
paths which would be created to manufacture the
enclosure much easier. After small adjustments were
made the model was finalized. The final model can
be seen in Figure 7. Next, NX CAM software was
used to develop the programs necessary to
manufacture the camera on the HAAS VF6 machine
in the productivity center. Sandvik Coromant
tooling was selected and purchased for the
necessary operations, and the CAM programs were
reviewed and post-processed. One fully functional
enclosure was machined, and subjected to testing.
First and most importantly, the enclosure’s
ability to resist coolant was tested. The fully
assembled enclosure was packed with paper and
submerged in a 5 gallon bucket filled with coolant.
The enclosure was left overnight, and after 15 hours
it was removed from the coolant and no leaks were
observed. Having passed this important test, less
crucial tests were conducted, mainly done to
observe the functionality of the GoPro camera
while in the enclosure. It was determined that the
camera’s field of view was not disturbed by the
housing body, and wireless signal from a GoPro Smart Remote could still be picked up. This was
not as expected, as a metal enclosure was predicted to fully compromise the camera’s ability to
get a signal from the remote. The remote’s ability to communicate with the camera in the
Figure 5. Water-tight button solution
Figure 6. 3D printed prototype
Figure 7. Solid Model ofthe Enclosure

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enclosure meant that the camera could be operated from outside the machine, greatly improving
its functionality.
The only major issue observed in the design was the camera’s inability to dissipate heat.
To keep the camera in place, it was originally surrounded by foam on all sides. The foam
provided thermal insulation for the camera however, causing it to become hot when used. To
remedy this situation, the lid design was changed to incorporate a raised contact pad. As shown
in Figure 8, this pad is
roughly the size of the
GoPro and essentially
turns the aluminum
enclosure into a heat sink,
allowing the camera to
dissipate heat into the
metal. After installing the
newly designed lid, the
surfaces of the enclosure
became warm to the touch,
leading to the conclusion
that the heat sink was
working correctly.
COSTS
Creating five custom enclosures
and equipping them with GoPro
cameras will cost Sandvik Coromant a
total of $4,710. This comes to a total
cost of $942 for each of the five units.
Subtracting the cost of the cameras, this
becomes $642 per camera enclosure. A
breakdown of the development and
material costs are outlined in Table 1
and Figure 9. Considering similar
enclosures retail for over $1000,
developing a custom enclosure in house
has saved the company a good deal of
money. Furthermore, the ability to
customize the camera enclosure to fit
the specific needs of the company
means that the final product is far more
functional than anything that could be
purchased off the shelf. Since the
development is already completed,
additional camera cases can be
manufactured for only the cost of the
materials, a mere $102.
Figure 8. Improved lid design featuring raised pad for heat
transfer
Item Price Quantity * Cost
Labor (per hour) $15 180 $2,700.00
GoPro Hero 3 $299.99 5 $1,499.95
6061 Al $57.90 5 $289.50
Cable Glands $5.74 10 $57.40
Lens Glass $8.10 5 $40.50
Grooved Pins $1.11 15 $16.65
Springs $0.86 15 $12.90
Washers $4.80 1 $4.80
Button O-rings $2.08 1 $2.08
Epoxy $6.27 1 $6.27
Hinge Pins $4.34 10 $43.40
Thumb Screws $9.87 1 $9.87
Foam $15.67 1 $15.67
Oil Rings $11.15 1 $11.15
Total: $4,710.14
Cost per unit: $942.03
Component Cost
* Items with quantity of 1 listed were
purchased in a single package of
sufficient quantity
Table 1. Cost Breakdown ofdeveloping a custom
enclosure

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CONCLUSION
Given the performance of the camera
enclosure during the testing stages, this project was
very successful. Not only was a camera enclosure
designed specifically for use in the machines, but it
also saved the company money. As a result of this
project, all the machines in the productivity center will
be equipped with full HD video cameras, and the
custom enclosures will protect them from the machine
environments. The enclosure with the GoPro Hero 3
installed can be seen to the right, in Figure 10.
Five camera enclosures were made in August
2015 for use in the Fair Lawn, NJ productivity center.
It is possible that other Sandvik Coromant facilities
could make use of this design, altering or improving it
for their specific needs.
REFERENCES
1. Fuchs Lubricants safety data sheet
https://www.cromwell.co.uk/safety/coshh/SOL/740/SOL7404570B_7.pdf
2. Chemical Resistance of various plastics
http://www.plasticsintl.com/plastics_chemical_resistence_chart.html
57%
32%
11%
Camera Project Cost Breakdown
Labor
GoPro HERO 3+ Silver
Housing Materials and Components
Figure 9. Relative cost ofproject components. Note that material costs account for just 11% ofthe
total, indicating that further manufacture of the camera enclosures would be relatively inexpensive.
Figure 10. The completed GoPro
enclosure ready for use