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KoalaSafe KS150N Pertinent Links (Prelude)

Recently while thrifting I came across and purchased a KoalaSafe KS150N "Family Friendly Wireless Router with Parental Technology" for approximately CAD$5. I recognized it as a popular type of miniature, USB-powered portable router of which I already have two from other vendors; apparently this was a popular whitelabel type of unit. Given that, I assumed it would probably be easy to install something like OpenWRT if not some other malleable firmware in the same vein. As further research has uncovered OpenWRT actually forms the basis of the firmware the OEM distributes these units with and is therefore also likely the basis of most or all firmwares issued by subsequent resellers. Given its small size and meagre power requirements a use can almost always be found for a router and access point of this sort, despite correspondingly limited and dated capabilities. I plan to return to this topic at length in the future but am extremely taxes for time at the moment so I'm putting a collection of the relevant links I've found here to make it easier to repurpose and write a more complete article about it later on.

Evidently the device was some sort of content filter/parental control that depended on the reseller's (KoalaSafe) cloud infrastructure to function. Interestingly, they chose to push a clean version of OpenWRT as an Over-The-Air Update (OTA) when they went out of business so at least its users would have a usable device instead of just bricking them all - I think that's a move worthy of respect and further investigation/reporting on when I get back to this topic.

Replacement Blades for DeWalt 25mm Tungsten-Carbide Snap-Off Shop/Utility Knife AKA Box Cutter

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DWHT10250

In the interest of never having to track down the exact replacement blades for my DEWALT 25mm Cartridge Blade Snap off Knife model # DWHT10250 with 25mm laser-deposited tungsten carbide (oOoOoOoh~) edge, please find below links to the 5 (DWHT11925) and 20 (DWHT11925F) packs of replacement 25mm snap-off blades.

Local hero AvE tears down and tears into the gimmicky tungsten-carbide coating which is typically used to make drill bits extra hard but is virtually useless at prolonging the longevity of a rough-and-tumble shop knife like this as its failure tends to stem from chipping of the blade edge which is not improved whatsoever by the additive.

It's not immediately clear how to reload one of these gadgets if you've not had to in years (or just never read the manual, as the case may be. but surely isn't...). These knives have the unique feature of being automatically reloadable; once a blade has been fully spend simply remove it by sliding it all the way off the end then return the slider to the fully retracted position, past the notch in the blades. Sliding forward once more catches the next blade in the cartridge, assuming there is one.

Now that we have our new blades the mission is not to install one that is active and pack a few into an onboard storage slot, as it is with virtually every other knife of this variety. Instead remove the blade cartridge by depressing the black tab and sliding outward from the back of the knife. Insert up to five blades backwards into the cartridge (it will be much easier to insert them as a single package rather than individually) until the latch actuates into their notch. Reinsert the cartridge into the knife housing and use the slider to load the active blade from the top of the stack by fully retracting it then sliding forward.

If you remove the slider you will note that the notch which selects and frees the active blade is an indentation of only a few micrometers - it is critical that when you use this knife you do not rely on the slider to retain the blade's position or you risk sliding the blade back into the cartridge or - much more dangerously - the blade may slide forward out of the housing and could even drop right out. Always make sure you use the locking knob after protruding the length of blade you wish to work with.

Reloading the cartridge is demonstrated in this video:

Things to make with a 3D Printer

A living list of things I intend to (and subsequently have) made with my 3D printer so I can keep track of ideas before they fall out of my ears and bounce away before they can make it to the printer. Or while I wait for a design to become available. Or while I wait for myself to give up waiting for someone else to do it and make one myself...

Before I bought a 3D Printer I promised myself that I would figure out at least one worthwhile, cost-saving or otherwise difficult to obtain item that I could make so I would never have the shame of being That Guy™ who buys a 3D printer and then just leaves it on a shelf. I made the same promise before buying a Raspberry Pi and have since owned four (and counting); perhaps this list will help you figure out something to do with the 3D printer you have in the mail or on your wish list that can help you avoid the shame of being That Guy (or Gal)™ too! :)

  • 18650 shoulder-short prevention cap
  • CR4040 adapter for CR3230 coin cell lithium batteries (for Microsoft wireless 10key)
  • Auto body removal tools (non-scratch spodgers)
  • Battery holders for various formats in varuous sizes
  • Raspberry Pi cases
  • Pwnagotchi cases
  • Bus Pirate cases
  • Project/demo/breakout board cases for the various ones I have in stock
  • Missing battery covers (for keyboards etc)
  • Libby's arcane weird thing: "Lian Li case clips" https://www.thingiverse.com/thing:2691439/files Lian Li PC-60FN female clip
  • Battery Organizer

Soundproof Server Rack/Acoustic Cabinet Wishlist

While Qubes will be moving to an architecture that allows you to run your AppVMs on remote machines, allowing you to employ an almost thin-client to mainframe-like architecture, when I first moved to Qubes from Gentoo as my daily driving workstation operating system the number of cores and amount of RAM available in a single system became of paramount importance on my human-interfacing edge devices. I had always wanted the reliability and redundancy features of rack mounted servers in my workstation and now an even better reason pushes me in that direction; you can get multi-socket systems just oozing with ECC ram for pennies on the dollar if you are willing to work with datacentre-focused servers that are just a few years older thanks to leasing arrangements, EoL policies and aggressive upgrading.

Soundproof Rack
Cheapest Retail 12U for ~CAD$1400 shipped

Having lost my house in the financial upheaval wrought by the COVID pandemic it's no longer a simple matter of running a bundle of actively amplified HDMI and USB cables up from my basement and into my office; if I want to use a rack mounted server or servers as part of my network operations workstation in any apartment I might find myself in while clawing my way back to financial contentment I would need to have them in the same room as me. Even modifying the fans of a typical rack mount server with resistors or throttling them though management interfaces - where that is even possible - still leaves me with a virtual jet engine next to me and this is not an acceptable proposition, especially for tasks that draw upon creative juices. The sound buggers with my chi, one might say.

The solution is to employ a soundproof rack, also called an "acoustic cabinet" but the problem is that the market for them is dominated by three companies and in an industry where brand new hardware is already overinflated in price the lack of competition has allowrd them to keep prices far above reason. Enough so that it makes sense for one to build one's own solution. While you might find it easier to start with an enclosed cabinet and seal its holes they tend to lack the kind of space between the outer panels and inner rack to do add much soundproofing material and more importantly, to construct air ducts that wind in such a way as to muffle sound while still permitting sufficient airflow that a few quiet brushless fans can provide adequate assistance to keep the now-stifled rackspace within optimal operating temperatures.

ATA Case Rack
16 space ATA Case with 19" Rack

Enclosed cabinets also tend to cost as much as half the price of their equivalently sized sounfproof options and that negates the savings necessary to make a DIY project like this worthwhile. Therefore I am leaning more toward incorporating a much cheaper open four-post rack into my design. Additionally, since moving again - and maybe again and again - is back in my future until a new house can be secured, mobility is important. I think it makes more sense to trust the selection of casters that a rack manufacturer has selected than to add another problem to my list and as such you will likely find more quater- to half-height racks and cabinets in this, my living list of potential materials that will be incorporated into my eventual work product.

An ATA Case (more commonly known as a "Road Case" or "Flight Case") enclosed rack may in fact provide the ideal starting point as they are designed with casters and substantial padding though not intended specifically for soundproofing and the enclosures are typically free from ventilation holes which otherwise need to be blocked if starting with a conventional enclosed cabinet. Replacing the material between rack and outer enclosure with materials engineered specifically for soundproofing properties may improve performance and would then only necessitate routing ventilation and adding an active ventilation system to ensure proper cooling while the devices are run inside the enclosure. In this context the term "space" is usually used instead of [rack] unit for the 1 1/4 inch standard equipment size unit and the depth of such cases are often expressed in spaces the same as their rack capacity, such that a 14 space rack in a case that is 14 spaces deep has installable dimensions of 24.5 (14*1.75) inches high by 24.5 inches deep with a width sufficient to accommodate "19-inch rack"-able equipment (approximately 17-17.5").

When (and if) finished you can expect a follow-up article, until then please enjoy and hopefully benefit from my brainstorming, note-taking and research as it grows below:

Notes

  • Though you will see pyramidal foam in professional cabinets this is mostly designed to absorb echo and high frequency sounds for improving recordings. A thin layer innermost facing the servers might be appropriate
  • An air cavity between layers of soundproofing material (any material) greatly increases efficacy and would make pyramidal foam as mentioned above much more useful than for its largely cosmetic effect
  • Bituminous foil applies a layer of this petro industrial product to aluminum or other metallic foil and was developed for the roofing profession before its excellent sound deadening properties were discovered.
  • Mass Loaded Vinyl is an extremely dense substance that provides excellent sound absorption and at least one layer should form the outermost soundproofing material layer in a soundproof enclosure.

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