Due to the fact that the housing does not have a proper threading for the front and back panel fastening, a surprisingly large amount of aluminium shavings get loose when you change the front panel. This can in theory create shorts and therefore have catastrophic effects on the device. I would recommend that joulescope change the front panel fastening somewhat.
Hi @bateau and welcome to the Joulescope forum! Thanks for the feedback!
I agree that the aluminum filings can be somewhat concerning, but it is very common with aluminum enclosures. In the previous-generation JS110, we used self-taping screws which generated a huge amount of aluminum shavings. We did not have a single failure in thousands of units that we can attribute to the presence of shavings inside the enclosure. The aluminum surface does oxidize pretty quickly which greatly increases its resistance, which may explain some of this.
With the new JS220, we do tap the holes first, which greatly reduces the amount of aluminum shavings inside the enclosure. Unfortunately, our tapping process was not great. For our next order of aluminum extrusions, we will have the factory perform tapping, which should help even more.
Aluminum is also a very soft metal, so you should use care to fit the screw with the existing threads. The steel screws can very easily cut new threads. When you first insert the screw, you need to turn it gently to seat the screw in the existing threads. If you use too much force initially, you may find that the screw is difficult to turn, which likely means that you are creating new threads and more shavings.
The presence of aluminum shavings is definitely an issue we track and work to minimize during manufacturing!
If I can weigh in a bit in a proposal: I found that using a larger thread pitch greatly reduces the risk of rethreading, and would be easier to manipulate when changing fronts. The present machine screws you use are 0.6mm pitch, you could try 1mm pitch for example.
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