It is time to move on - a new year brings new challenges. Luckily some week before Christmas the last perceived challenges of the Detectron case mod were overcome, and in this post round up photos of the finalized exterior and interior will be shown. Some pretty creative kitchen engineering was performed to achieve the correct tactile feedback for the stepped knob, as well as some draconian cutting to improve air-flow.
Compared to previous pictures, it can be noted that air intakes (on the top and bottom) have vastly increased in size. This follow from the heat problems experienced in the initial cooling solution. The other change is the completely new air outlet on the front of the case. To make this the original text explaining how to calibrate the Detectron had to be sacrificed, but that was anyway not applicable, and proper function was deemed more important.
The rationale on the air flow is as follows. When running with open lid, there was never any problem with heat, meaning that the CPU-fan is likely capable of handling the i5 CPU. The problem was that air flow though the case was too limited, probably due the the undersized case fan and small air vents. The first part of abbreviating this was therefore to open up more air holes. Secondly, in the original configuration, the CPU-fan was sucking in air to blow at the CPU grill. This air was then heated and ended up in the case, effectively heating the case using the CPU! That would not help in the long run. Therefore the CPU-fan direction was reversed to suck air from inside the case and blowing it out, making it double as a case fan. This could mean slightly worse CPU-cooling as the case interior air is likely a little bit warmer that air outside the case, but this is likely not crucial. Finally, air flow was optimized by turning the CPU grill 90 degrees to align it with the air inlets.
Mounting all the Phidget input boards and sensors was pretty crowded, but all in all quite smooth. Lots of cable work was required to shorten the sensor to board cables, and also to make a two-to-one mini USB to internal USB2 cable. As can be seen, the Phidget interface board had to be raised to make room for the power and HDD LEDs and some sensors underneath, which was tight considering there was only 20 mm to work with.
The old ampere-meter was modified with a resistor (can't remember the value at the moment) to tune it to 0-10V input, and the connected to the Phidget analogue board that was bought for this specific reason. Further, three white LEDs were built into the meter, to later allow for three different modes. These were connected to the Phidget interface board, as well as the other sensors.
For being the most intriguing part of the above figures, the cog-wheels need a special mention. The problem here was that the stepped knob that will control the what is shown on the ampere-meter, needs to feel stepped. Simply tucking a rotation sensor behind it would work, but feel pretty unsatisfying to use. Therefore the old mechanical stepping device needed to be included, but the narrow height of 20 mm made it impossible to have that followed by a co-axial rotation sensor. This is were the cog-wheels come in, to transport the mechanically stepped knob axis onto the flipped rotation sensor axis. As the reader might suspect, no cog-wheels of suitable size were available in the workshop kitchen used during the Detectron construction. These cog-wheels were custom made from to kids paracetamol bottle corks, proving the utility of drugs in case modding.
Construction of the the CPU air outlet required completely remaking the SSD mounts, which is the and resulted in a slightly lower profile, which really helped making the closing of the lid easier, along with the complete removal of the interior back panel to allow for air flow.
Someday in the future, the final piece of the Detectron will slid into place, which is the little program required to make all the buttons and dials work. When this will occur is a bit beyond prediction unfortunately, but at that time an epilogue will come. As mentioned, the focus of this blog will now move to software programming, as the author resuming PhD-studies after half a year of parental leave. We thus thank the Swedish welfare system for bringing us this far, and open our arms to embrace the future.
